Syndecan-1 Protein Expression Research Articles

Astragaloside IV Protects against Shear Stress-Induced Glycocalyx Damage and Alleviates Abdominal Aortic Aneurysm by Regulating miR-17-3p/Syndecan-1

Background. The present study aimed to analyze the impact of astragaloside IV (AS-IV) on abdominal aortic aneurysm (AAA) and the glycocalyx, elucidating the potential mechanism of AS-IV. Methods. Rat models of AAA were established using porcine pancreatic elastase. The effects of intraperitoneal AS-IV injection on the morphology, diameter, and glycocalyx of the aorta and the expression of miR-17-3p and Syndecan-1 (SDC1) protein were examined. Differentially expressed miRNAs from peripheral blood samples of healthy individuals, untreated patients with AAA, and treated patients with AAA were identified through sequencing. The relationship between miR-17-3p and SDC1 was validated using a dual-luciferase reporter assay. In vitro, shear stress was induced in human aortic endothelial cells (HAECs) to simulate AAA. Overexpression of miR-17-3p was performed to assess the effects of AS-IV on miR-17-3p and SDC1 expressions, apoptosis, and glycocalyx in HAECs. Results. AS-IV mitigated aortic damage in AAA rats, reducing the aortic diameter and alleviating glycocalyx damage. In addition, it suppressed the increase in miR-17-3p expression and promoted SDC1 expression in AAA rats. Peripheral blood miR-17-3p levels were significantly higher in patients with AAA than in healthy individuals. miR-17-3p inhibited the SDC1 protein expression in HAECs. In the in vitro AAA environment, miR-17-3p was upregulated and SDC1 was downregulated in HAECs. AS-IV inhibited miR-17-3p expression, promoted SDC1 expression, and mitigated shear stress-induced apoptosis and glycocalyx damage in HAECs. Overexpression of miR-17-3p blocked AS-IV–induced SDC1 expression promotion, glycocalyx protection, and apoptosis suppression in HAECs. Conclusion. miR-17-3p may damage the glycocalyx of aortic endothelial cells by targeting SDC1. AS-IV may promote SDC1 expression by inhibiting miR-17-3p, thereby protecting the glycocalyx and alleviating AAA.

Ultrasensitive Immunoprofiling of Plasma Extracellular Vesicles Identifies Syndecan-1 as a Potential Tool for Minimally Invasive Diagnosis of Glioma.

Liquid biopsy has great potential to improve the management of brain tumor patients at high risk of surgery-associated complications. Here, the aim was to explore plasma extracellular vesicle (plEV) immunoprofiling as a tool for noninvasive diagnosis of glioma. PlEV isolation and analysis were optimized using advanced mass spectrometry, nanoparticle tracking analysis, and electron microscopy. We then established a new procedure that combines size exclusion chromatography isolation and proximity extension assay-based ultrasensitive immunoprofiling of plEV proteins that was applied on a well-defined glioma study cohort (n = 82). Among potential candidates, we for the first time identify syndecan-1 (SDC1) as a plEV constituent that can discriminate between high-grade glioblastoma multiforme (GBM, WHO grade IV) and low-grade glioma [LGG, WHO grade II; area under the ROC curve (AUC): 0.81; sensitivity: 71%; specificity: 91%]. These findings were independently validated by ELISA. Tumor SDC1 mRNA expression similarly discriminated between GBM and LGG in an independent glioma patient population from The Cancer Genome Atlas cohort (AUC: 0.91; sensitivity: 79%; specificity: 91%). In experimental studies with GBM cells, we show that SDC1 is efficiently sorted to secreted EVs. Importantly, we found strong support of plEVSDC1 originating from GBM tumors, as plEVSDC1 correlated with SDC1 protein expression in matched patient tumors, and plEVSDC1 was decreased postoperatively depending on the extent of surgery. Our studies support the concept of circulating plEVs as a tool for noninvasive diagnosis and monitoring of gliomas and should move this field closer to the goal of improving the management of cancer patients.

Dose and timing of normal saline resuscitation on endothelial glycocalyx in early septic shock

To observe the effect of different doses and timing of normal saline (NS) resuscitation combined with norepinephrine (NE) on endothelial glycocalyx in rabbits with early septic shock. Thirty New Zealand male rabbits were randomly divided into sham group, model group, 30 mL and 60 mL timely resuscitation groups (30 mL and 60 mL timely group), and 30 mL delayed resuscitation group (30 mL delayed group) with 6 rabbits in each group. The rabbit model of septic shock was reproduced by cecal ligation and puncture (CLP). The rabbits in sham group were only received abdominal cavity open without cecal and ligation. The rabbits in 30 mL and 60 mL timely groups and 30 mL delayed group were intravenous infused with 30 mL/kg or 60 mL/kg NS immediately or 1 hour after model reproduction for 1 hour, and the mean arterial pressure (MAP) was maintained over 75 mmHg (1 mmHg = 0.133 kPa) compared with intravenous pumping of 0.02-0.05 μg×kg-1×min-1 NE followed by 5 mL/h NS infusion till the end of the experiment. The rabbits in sham and model groups were only given 5 mL/h NS. The changes in arterial blood gas before and immediately after resuscitation were observed in three fluid resuscitation groups. The internal jugular vein blood was collected at 0, 3, 6 hours after model reproduction. The levels of syndecan-1 (polysaccharide envelope marker) in plasma were determined by enzyme linked immunosorbent assay (ELISA). The rabbits were sacrificed at 6 hours after model reproduction, and the lung tissue was harvested. Western Blot was used to determine the protein expressions of intercellular adhesion molecule-1 (ICAM-1), matrix metalloproteinase 2 (MMP-2) and syndecan-1. The positive expression of syndecan-1 in lung tissue was observed by immunohistochemical method. (1) Blood gas analysis: compared with the results before resuscitation, the levels of lactic acid (Lac) after resuscitation in three fluid resuscitation groups were significantly decreased, especially in 30 mL timely group; the central venous blood oxygen saturation (ScvO2) was significantly increased, especially in 30 mL delayed group. Oxygenation index (PaO2/FiO2) was improved in 30 mL timely and 30 mL delayed resuscitation groups, which was decreased in 60 mL delayed group. (2) Plasma marker: compared with sham group, plasma syndecan-1 level in model group was significantly increased with a time-dependent manner. Plasma syndecan-1 levels at 3 hours in 30 mL timely and 30 mL delayed groups were significantly decreased as compared with those of model group (ng/L: 138.0±2.4, 139.7±15.7 vs. 161.5±4.1, both P < 0.05), but it was significantly increased at 6 hours in 30 mL delayed group (ng/L: 213.1±19.4 vs. 206.4±15.5, P < 0.05). The plasma syndecan-1 levels at 3 hours and 6 hours in 60 mL timely group were significantly higher than those in model group (ng/L: 233.0±28.9 vs. 161.5±4.1, 252.3±27.2 vs. 206.4±15.5, both P < 0.05). (3) Protein expression in lung tissue: compared with sham group, the protein expressions of ICAM-1 and MMP-2 in lung tissue of model group were significantly increased, and syndecan-1 protein expression was significantly decreased. After 30 mL timely or 30 mL delayed resuscitation, the protein expressions of ICAM-1 and MMP-2 in lung tissue were significantly decreased, and syndecan-1 protein expression was significantly increased, especially in 30 mL timely group, which showed statistical differences as compared with those of model group (ICAM-1 protein: 0.56±0.09 vs. 1.04±0.05, MMP-2 protein: 0.83±0.15 vs. 1.06±0.06, syndecan-1 protein: 2.09±0.08 vs. 0.99±0.03, all P < 0.05). The change tendency of protein expressions in 60 mL timely group was opposite to the other two resuscitation groups. (4) Immunohistochemistry: the positive expression of syndecan-1 in lung tissues was significant in the sham group, and it was lowered in model group. The positive expression of syndecan-1 was increased after 30 mL timely or 30 mL delayed resuscitation, but further weakened in 60 mL timely group. The dose and timing of resuscitation with NS in septic shock can affect pulmonary vascular endothelial glycocalyx function. The timely resuscitation with 30 mL NS in combination with NE plays a protective effect on endothelial cell and glycocalyx. However, NS resuscitation which was not timely or excessive infusion can make the glycocalyx degradation more obvious, resulting in increased endothelial permeability, microcirculation damaged, thus aggravate lung injury.

MicroRNA-494 acts as a tumor suppressor in pancreatic cancer, inhibiting epithelial-mesenchymal transition, migration and invasion by binding to SDC1.

Pancreatic cancer (PC) is the fourth most common cause of cancer‑related mortality in the industrialized world. Emerging evidence indicates that a variety of microRNAs (miRNAs or miRs) are involved in the development of PC. The aim of the present study was to elucidate the mechanisms through which miR‑494 affects the epithelial‑mesenchymal transition(EMT) and invasion of PC cells by binding to syndecan1(SDC1). PC tissues and pancreatitis tissues were collected, and the regulatory effects of miR‑494 on SDC1 were validated using bioinformatics analysis and a dual‑luciferase report gene assay. The cell line with the highest SDC1 expression was selected for use in the following experiments. The role of miR‑494 in EMT was assessed by measuring the expression of SDC1, E‑cadherin and vimentin. Cell proliferation was assessed using a cell counting kit (CCK)‑8 assay, migration was measured using a scratch test, invasion was assessed with a Transwell assay and apoptosis was detected by flow cytometry. Finally, a xenograft tumor model was constructed in nude mice to observe tumor growth invivo. We found that SDC1 protein expression was significantly higher in the PC tissues. SDC1 was verified as a target gene of miR‑494. The SW1990 cell line was selected for use in further experiments as it had the lowest miR‑494 expression and the highest SDC1 expression. Our results also demonstrated that miR‑494 overexpression and SDC1 silencing significantly decreased the mRNA and protein expression of SDC1 and vimentin in SW1990 cells, while it increased E‑cadherin expression and apoptosis, and inhibited cell growth, migration, invasion and tumor growth. On the whole, the findings of this study demonstrated that miR‑494 is able to downregulate SDC1 expression, thereby inhibiting the progression of PC. These findings reveal a novel mechanism through which miR‑494 affects the development of PC and may thus provide a basis for the application of miR‑494 in pancreatic oncology.

Clinical implications in the shift of syndecan-1 expression from the cell membrane to the cytoplasm in bladder cancer

BackgroundTo determine the diagnostic and prognostic capability of urinary and tumoral syndecan-1 (SDC-1) levels in patients with cancer of the urinary bladder.MethodsSDC-1 levels were quantitated by enzyme-linked immunosorbent assay (ELISA) in 308 subjects (102 cancer subjects and 206 non-cancer subjects) to assess its diagnostic capabilities in voided urine. The performance of SDC-1 was evaluated using the area under the curve of a receiver operating characteristic curve. In addition, immunohistochemical (IHC) staining assessed SDC-1 protein expression in 193 bladder specimens (185 cancer subjects and 8 non-cancer subjects). Outcomes were correlated to SDC-1 levels.ResultsMean urinary levels of SDC-1 did not differ between the cancer subjects and the non-cancer subjects, however, the mean urinary levels of SDC-1 were reduced in high-grade compared to low-grade disease (p < 0.0001), and in muscle invasive bladder cancer (MIBC) compared to non-muscle invasive bladder cancer (NMIBC) (p = 0.005). Correspondingly, preliminary data note a shift from a membranous cellular localization of SDC-1 in normal tissue, low-grade tumors and NMIBC, to a distinctly cytoplasmic localization in high-grade tumors and MIBC was observed in tissue specimens.ConclusionAlone urinary SDC-1 may not be a diagnostic biomarker for bladder cancer, but its urinary levels and cellular localization were associated with the differentiation status of patients with bladder tumors. Further studies are warranted to define the potential role for SDC-1 in bladder cancer progression.

Role of syndecan‐1 (CD138) in cell survival of human urothelial carcinoma

Heparan sulfate proteoglycan syndecan-1, CD138, is well known to be associated with cell proliferation, adhesion, and migration in various types of malignancies. In the present study, we focused on the role of syndecan-1 in human urothelial carcinoma of the urinary bladder. Silencing of syndecan-1 by siRNA transfection down-regulated transcriptional factor junB and the long isoform of FLICE-inhibitory protein (FLIP long), resulting in the induction of apoptosis in the urothelial carcinoma cell lines UMUC2 and UMUC3. Knockdown of junB and FLIP long as well as syndecan-1 silencing mediated apoptosis that was inhibited by pan-caspase inhibitors. Transurethral injection of syndecan-1 siRNA into the urinary bladder significantly reduced syndecan-1 gene expression and growth of red fluorescent-labeled KU-7/RFP bladder cancer cells in the mouse orthotopic bladder cancer model. Immunohistochemical examination showed high syndecan-1 protein expression in high-grade, superficial, and deep invasive carcinomas (pT1 and >or=pT2) as well as carcinoma in situ, but not in low-grade and noninvasive phenotypes (pTa). In addition, the percentage of cancer cells positive for syndecan-1 at initial diagnosis was statistically associated with the frequency of bladder cancer recurrence after transurethral resection. In conclusion, syndecan-1 might contribute to urothelial carcinoma cell survival and progression; therefore, this molecule could be a new therapeutic target in human urinary bladder cancer.

Decoupled syndecan 1 mRNA and protein expression is differentially regulated by angiotensin II in macrophages

It has been established that syndecan-1 is an important modulator of events relevant to acute tissue repair and chronic injury responses. The current studies were designed to examine syndecan-1 expression during atherosclerotic lesion formation and whether angiotensin II influences syndecan-1 expression in macrophages. ApoE knockout mice maintained on an atherogenic diet were treated for 8 weeks with an infusion of angiotensin II to induce atherosclerosis. Immunohistochemistry was employed to characterize the expression of syndecan-1 in atherosclerotic lesions. Quantitative real-time PCR (QRTPCR) was used to define the role of angiotensin II and responsible signaling pathways involved syndecan-1 expression in RAW264.7 murine macrophages. Protein expression and shedding were characterized by fluorescence activated cell sorting (FACS) and slot blot analysis. Syndecan-1 was abundantly expressed in macrophages located within early atherosclerotic lesions. Accordingly, we hypothesized that angiotensin II regulates syndecan-1 expression in macrophages. A time- and dose-dependent study was performed in RAW264.7 macrophages. QRTPCR demonstrated maximum syndecan-1 mRNA up-regulation at 6 h after 500 nM AgII stimulation (threefold; P < 0.05). Through administration of specific inhibitors, we established that ERK/MAPK, PI3K and JNK signaling pathways mediated this effect. FACS and slot blot analyses demonstrated that cAMP induced posttranscriptional syndecan-1 protein expression in a dose-dependent manner with or without initial angiotensin II stimulation. In particular, angiotensin II induced an increase in cell surface syndecan-1 (mean fluorescence intensity: 147 +/- 5.7 vs. 176 +/- 4.8; P < 0.05; n = 3) and accelerated syndecan-1 shedding. Angiotensin II is a potent regulator of syndecan-1 expression in atherosclerotic lesions via a specific effect on macrophages that is mediated by ERK/MAPK, PI3K, and JNK signaling pathways.

Immunohistochemical Localization of Syndecan‐1 in the Dental Follicle of Postnatal Mouse Teeth

Syndecans are cell surface heparan sulfate proteoglycans that modulate the action of growth factors and extracellular matrix components. Syndecan-1 plays important roles during early tooth development, and it is expressed in the dental follicle of fetal tooth germ. However, no studies have followed its expression in the dental follicle during the postnatal period. We hypothesized that syndecan-1 protein expression in the dental follicle may be important for postnatal tooth development, and, thus, examined its expression patterns. Syndecan-1 protein expression in the dental follicle of the lower first molar was investigated by immunohistochemistry using embryonic day (E) 18.5 to 21-day-old (d 21) mice. Immunoelectron microscopy was applied to the dental follicle and pulp cells to confirm its membrane localization in mesenchymal cells. Strong syndecan-1 immunostaining was maintained in the dental follicle and the adjacent dental pulp surrounded by the Hertwig's epithelial root sheath (HERS) from d 4 to d 14, but reduced staining was noted at d 21 with the near-completion of tooth eruption. Three dimensionally, syndecan-1-positive areas plugged the apical foramina surrounded by HERS. However, immunostaining was detected constantly in the dental follicle and the dental pulp of the lower incisor at d 21. In addition, membrane localization of syndecan-1 protein was confirmed for the first time in mesenchymal cells, including dental follicle and pulp cells, by immunoelectron microscopy. The spatial and temporal expression of syndecan-1 in the dental follicle suggests that this proteoglycan is important for the maintenance of proliferation and/or movement of cells in this region during tooth eruption.

Expression of syndecan-1 (CD138) in nasopharyngeal carcinoma is correlated with advanced stage and poor prognosis

Nasopharyngeal carcinoma (NPC) is an important Epstein-Barr virus-associated head and neck malignancy in Taiwan. Syndecan-1 (CD138) is involved in growth, differentiation, invasiveness, and metastatic potential of certain tumors, but its expression in NPC has never been studied. In this study, detection of expression of syndecan-1 protein and Epstein-Barr virus-encoded latent membrane protein-1 (LMP-1) in primary, recurrent, and metastatic NPC specimens in paraffin sections was performed by immunohistochemistry. The quantity of syndecan-1 messenger RNA in tumor cells was investigated by real-time reverse transcriptase polymerase chain reaction using laser capture microdissection. The results of immunohistochemical staining of syndecan-1 and LMP-1 correlated with clinicopathologic features of NPC. Eighteen (20.9%) of 86 primary, 9 (24.3%) of 37 recurrent, and 15 (44.1%) of 34 metastatic NPC samples were positive for syndecan-1, and 37 (43.0%) primary, 18 (48.6%) recurrent, and 12 (35.3%) metastatic samples were positive for LMP-1 expression. Primary NPCs with syndecan-1 protein expression were more frequently associated with advanced clinical stages and worse 5-year survival rates than those without (P = .015 and P = .0021, respectively). Conversely, the LMP-1 expression did not correlate with tumor stage or prognosis but occurred more often in nonkeratinizing carcinoma than keratinizing squamous cell carcinoma (unpublished observation). The inverse expression of syndecan-1 and LMP-1 was noted in primary NPC specimens (total 4/18 versus 35/68, P = .05). The reverse transcriptase polymerase chain reaction revealed low syndecan-1 messenger RNA levels in both primary and metastatic NPC. In conclusion, the protein expression of syndecan-1 in 21% of primary NPC was associated with advanced disease and poor prognosis, and the protein expression correlated with transcription levels.

Reduced expression of syndecan-1 affects metastatic potential and clinical outcome in patients with colorectal cancer.

Syndecan‐1 is a transmembrane heparansulfate proteoglycan which regulates cell‐to‐cell or cell‐to‐extracellular matrix interactions and may influence malignant cell behavior. We investigated the alterations of syndecan‐1 expressions in colorectal cancers and analyzed the relationship between histological and clinical characteristics. Syndecan‐1 protein expression in colorectal cancer tissues was investigated with immunohistochemical staining of resected specimens. In situ hybridization was performed using syndecan‐1 riboprobe to confirm the transcriptional signals. Syndecan‐1 mRNA expression in cancer cell lines cultured with or without methylation inhibitor was also analyzed by quantitative PCR. Out of 105 specimens tested, less than 25% of tumor cells were stained with anti‐syndecan‐1 monoclonal antibody in 36 (34.3%). In situ hybridization showed a similar staining profile to that of immunohistochemistry. Syndecan‐1 mRNA expression was increased by the methylation inhibitor 5‐aza‐2′‐deoxycytidine, suggesting that the hypermethylation is involved in the suppression of syndecan‐1 expression. Clinically, the incidence of metastasis to lymphnode or liver in patients with syndecan‐1‐negative tumors was significantly high. Among Tl colorectal cancers displaying a primary invasive phase, lymphnode metastasis, undifferentiated characters and ‘budding’ of cancer cells were more common in syndecan‐1‐negative tumors. The survival rate in patients with syndecan‐1‐negative tumors was decreased significantly in a stage‐independent manner. These results suggest that the reduction of syndecan‐1 expression in colorectal cancer cells, which is supposed to be regulated at the transcription level, is closely related to invasive character. The evaluation of syndecan‐1 expression in colorectal cancer may allow prediction of patients' survival after surgery