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Secreted protein, acidic and rich in cysteine‐like 1 (SPARCL1) belongs to the SPARC family of matricellular proteins. However, underlying functions of SPARCL1 in bladder cancer (BCa) remain understudied. We performed an integrated search for the expression patterns of SPARCL1 in relation to various clinicopathological features of BCa. We then carried out Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and gene set enrichment analysis (GSEA). Furthermore, we investigated the correlations between SPARCL1 and immunological features, such as tumour mutation burden (TMB), immune activation processes, immune checkpoint expression, tumour immune dysfunction and exclusion (TIDE) scores, and chemotherapeutic sensitivity in BCa. Our analysis revealed that SPARCL1 was downregulated across multiple cancers. In BCa, elevated SPARCL1 was linked with advanced histopathologic stage, higher T and N stage, and poorer prognosis in the clinical cohort. In vitro experiments demonstrated that increased SPARCL1 expression inhibited cell proliferation, migration, and invasion. Additionally, highly expressed SPARCL1 was linked to elevated immune, stromal and ESTIMATE scores, as well as an increase in naive B cells, M2 macrophages, and resting mast cells. We observed a moderate correlation between SPARCL1 expression and CD163, VSIG4 and MS4A4A, which are markers of M2 macrophages. Furthermore, SPARCL1 expression was positively related to TMB, immune activation processes, TIDE scores, immune checkpoint expression, and chemotherapeutic sensitivity in BCa. Our study highlights the potential involvement of SPARCL1 in macrophage recruitment and polarization and suggests its utility as a biomarker for prognosis in BCa. [ABSTRACT FROM AUTHOR]

Objectives: SPARCL1 is a matricellular protein that mediates the cell–matrix interactions and participates in physiological processes such as cell adhesion, differentiation and proliferation. However, its role in chondrocyte and osteoarthritis (OA) progression has not been fully characterized. We aimed to evaluate the effects of SPARCL1 on OA through in vitro and in vivo experiments. Methods: Expression of SPARCL1 was examined in 55 paired human OA samples. Effects of Sparcl1 on chondrocytes were identified in vitro. Intra-articular injection was performed in an anterior cruciate ligament transection (ACLT) mouse model. Alterations of SPARCL1-mediated signaling pathway were identified by RNA-seq analysis. qPCR and western-blot were used to demonstrate the potential signaling pathway. Results: SPARCL1 expression in the OA cartilage was increased compared with undamaged cartilage. Recombinant Sparcl1 protein induced extracellular matrix degradation in chondrocytes. Furthermore, intra-articular injection of recombinant Sparcl1 protein in ACLT mice could promote OA pathogenesis. Mechanistically, Sparcl1 activated TNF/NF-κB pathway and consequently led to increased transcription of inflammatory factors and catabolism genes of cartilage, which could be reversed by NF-κB inhibitor BAY 11–7082. Conclusion: SPARCL1 could promote extracellular matrix degradation and inflammatory response to accelerate OA progression via TNF/NF-κB pathway. The translational potential of this article: The current research could help to gain further insights into the underlying molecular mechanism in OA development, and provides a biological rationale for the use of SPARCL1 as a potential therapeutic target of OA.

Epidermal growth factor (EGF) repeats are present in various proteins and form well-defined structures with three disulfide bonds. One representative protein is the Notch receptor. Each EGF repeat contains unique atypical O-linked glycans, such as O-linked N-acetylglucosamine (O-GlcNAc). To generate a monoclonal antibody against the O-GlcNAc moiety in mouse Notch1, we expressed the recombinant C-terminal His6-tagged Notch1 EGF14-15 protein in HEK293T cells to prepare the immunogen. Most of the proteins were not secreted and showed higher molecular weight ladders in the cell lysate, suggesting protein aggregation. To overcome this issue, we fused Sparcl1 as an extracellular escorting tag to the N-terminus of Notch1 EGF14-15. The fusion protein was efficiently secreted extracellularly without protein aggregates in the lysates. Following PreScission protease treatment, Notch1 EGF14-15 was efficiently released from the escorting tag. Notch1 EGF14-15 prepared using this method was indeed O-GlcNAcylated. The optimal length of the escorting tag was determined by generating deletion mutants to improve the extracellular secretion of EGF14-15. Hence, a large amount of EGF14-15 was successfully prepared from the culture supernatant of HEK293T cells, which were otherwise prone to aggregation. [ABSTRACT FROM AUTHOR]

Objective To investigate the relationship between the expression of SLIT3 and SPARCL1 protein and the recurrence of cervical cancer after radical operation. Methods From October 2019 to April 2021, 107 patients who underwent radical surgery for cervical cancer in the hospital were selected as the study subjects, and 30 patients with benign uterine lesions were selected as the control group ; The patients were followed up for 1 year and were divided into relapse group (n = 25) and non relapse group (n = 82) according to the follow-up results. The expression levels of SLIT3 and SPARCL1 mRNA were detected by real-time fluorescence quantitative analysis (qPCR), and the expression levels of SLIT3 and SPARCL1 protein were detected by immunohistochemistry. The correlation between the expression of SLIT3 and SPARCL1 protein and clinicopathological characteristics was analyzed. Cox model was used to analyze the risk factors of cervical cancer recurrence after radical operation. Results The expression of SLIT3 and SPARCL1 mRNA in cervical cancer group was significantly lower than that in control group (P < 0.05) ; The levels of SLIT3 and SPARCL1 mRNA in cervical cancer tissues of patients with recurrence were significantly lower than those of patients without recurrence (P < 0.05).Among 107 patients with radical operation, 25 patients recurred, the recurrence rate was 23.36%. The postoperative recurrence rate of patients with low expression of SLIT3 (31.15%) was significantly higher than that of patients with high expression of SLIT3 (13.04%). The postoperative recurrence rate of patients with low expression of SPARCL1 (32.31%) was significantly higher than that of patients with high expression of sparcli (9.52%). The difference was statistically significant (P < 0.05). The expression of SLIT3 and SPARCL1 in cervical cancer was correlated with the degree of differentiation, clinical stage, lymph node metastasis and depth of stromal invasion (P < 0.05), but not with age, pathological type and maximum diameter of tumor (P > 0.05 ). Cox univariate analysis showed that the degree of differentiation, clinical stage, lymph node metastasis, stromal invasion depth, SLIT3 protein expression and SPARCL1 protein expression were correlated with the recurrence of cervical cancer patients after radical surgery (P < 0.05 ) ; Cox multivariate analysis showed that moderate/high differentiation, stage IIA, lymph node metastasis, stromal invasion depth > 50%, low expression of SLIT3 protein and SPARCL1 protein were independent risk factors for recurrence of cervical cancer patients after radical surgery (P < 0.05). Conclusion the expression of SLIT3 and SPARCL1 in cervical cancer tissue is lower than that in normal cervical tissue. The low expression of SLIT3 and SPARCL1 protein is an independent risk factor for the recurrence of cervical cancer after radical operation, and has certain clinical significance in predicting the recurrence of cervical cancer after operation. [ABSTRACT FROM AUTHOR]

Objective:To analyze the influences of secreted protein acidic and rich in cysteines-like protein 1 (SPARCL1) on the proliferation,apoptosis and invasion of non-small cell lung cancer (NSCLC) cells,and to explore the role of Mitogen activation inhibitor(MEK)/Extracellular regulated protein kinase (ERK) pathway in it.Methods:From September 2019 to June 2021,the cancer tissues and corresponding adjacent tissues of 84 NSCLC patients who received surgical treatment in our hospital were collected,real time quantitative reverse transcription polymerase chain reaction (qRT-PCR) method was applied to measure and compare the expression level of SPARCL1 messenger RNA (m RNA) in tissues and normal lung epithelial cells HBEpiC and NSCLC cells A549,HCC827,H1299 and H292.A549 and HCC827 were selected for culture and grouping,they were divided into control group,NC si RNA group,SPARCL1si RNA group,U0126 group (MEK/ERK specific inhibitor),and SPARCL1 si RNA plus U0126 group.Cell counting kit 8 (CCK8) method and the plate cloning method were used to measure the proliferation of A549 and HCC827 cells,flow cytometry was applied to determine the apoptosis of A549 and HCC827 cells,Transwell chamber method was applied to determine the invasive ability of A549 and HCC827cells,Western blot was applied to detect the protein expression of SPARCL1,p-MEK,MEK,p-ERK1/2,ERK1/2.Results:The SPAR-CL1 m RNA expression level in NSCLC tissues was lower than that in adjacent tissues (P＜0.05).Compared with HBEpiC cells,the SPARCL1 m RNA expression level in NSCLC cells A549,HCC827,H1299 and H292 cells decreased (P＜0.05).Compared with the control group,the SPARCL1 m RNA expression level,protein expression and apoptosis rate of A549 and HCC827 cells in SPARCL1 si RNA group decreased (P＜0.05),the OD450,number of colonies formed,number of invasive cells,p-MEK/MEK,and p-ERK1/2/ERK1/2 protein expression increased (P＜0.05),the SPARCL1 m RNA expression level,protein expression and apoptosis rate of A549 and HCC827 cells in the U0126 group increased (P＜0.05),the OD450,number of colonies formed,number of invasive cells,p-MEK/MEK,and p-ERK1/2/ERK1/2 protein expression decreased(P＜0.05).Compared with the SPARCL1 si RNA group,the SPARCL1 m RNA expression level,protein expression and apoptosis rate of A549 and HCC827 cells in SPARCL1 si RNA plus U0126 group increased (P＜0.05),the OD450,number of colonies formed,number of invasive cells,p-MEK/MEK,and p-ERK1/2/ERK1/2 protein expression decreased (P＜0.05)Conclusion:SPARCL1 may affect the proliferation,invasion and apoptosis of A549 and HCC827 cells by regulating MEK/ERK pathway. [ABSTRACT FROM AUTHOR]

Background. The liver is the third most common metastatic site for advanced breast cancer (BC), and liver metastases predict poor prognoses. However, the characteristic biomarkers of BC liver metastases and the biological role of secreted protein acidic and rich in cysteine-like 1 (SPARCL1) in BC remain unclear. The present study aimed to identify potential biomarkers for liver metastasis of BC and to investigate the effect of SPARCL1 on BC. Methods. The publicly available GSE124648 dataset was used to identify differentially expressed genes (DEGs) between BC and liver metastases. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to annotate these DEGs and understand the biological functions in which they are involved. A protein-protein interaction (PPI) network was constructed to identify metastasis-related hub genes and further validated in a second independent dataset (GSE58708). Clinicopathological correlation of hub gene expression in patients with BC was determined. Gene set enrichment analysis (GSEA) was performed to explore DEG-related signaling pathways. SPARCL1 expression in BC tissues and cell lines was verified by RT-qPCR. Further in vitro experiments were performed to investigate the biological functions of SPARCL1 in BC cells. Results. We identified 332 liver metastasis-related DEGs from GSE124648 and 30 hub genes, including SPARCL1, from the PPI network. GO and KEGG enrichment analyses of liver-metastasis-related DEGs revealed several enriched terms associated with the extracellular matrix and pathways in cancer. Clinicopathological correlation analysis of SPARCL1 revealed that its expression in BC was associated with age, TNM stage, estrogen receptor status, progesterone receptor status, histological type, molecular type, and living status of patients. GSEA results suggested that low SPARCL1 expression in BC was related to the cell cycle, DNA replication, oxidative phosphorylation, and homologous recombination. Lower expression levels of SPARCL1 were detected in BC tissues compared to adjacent tissues. The in vitro experiments showed that SPARCL1 knockdown significantly increased the proliferation and migration of BC cells, whereas the proliferation and migration were suppressed after elevating the expression of SPARCL1. Conclusion. We identified SPARCL1 as a tumor suppressor in BC, which shows potential as a target for BC and liver metastasis therapy and diagnosis. [ABSTRACT FROM AUTHOR]

Astrocytic-secreted matricellular proteins have been shown to influence various aspects of synaptic function. More recently, they have been found altered in animal models of psychiatric disorders such as drug addiction. Hevin (also known as Sparc-like 1) is a matricellular protein highly expressed in the adult brain that has been implicated in resilience to stress, suggesting a role in motivated behaviors. To address the possible role of hevin in drug addiction, we quantified its expression in human postmortem brains and in animal models of alcohol abuse. Hevin mRNA and protein expression were analyzed in the postmortem human brain of subjects with an antemortem diagnosis of alcohol use disorder (AUD, n = 25) and controls (n = 25). All the studied brain regions (prefrontal cortex, hippocampus, caudate nucleus and cerebellum) in AUD subjects showed an increase in hevin levels either at mRNA or/and protein levels. To test if this alteration was the result of alcohol exposure or indicative of a susceptibility factor to alcohol consumption, mice were exposed to different regimens of intraperitoneal alcohol administration. Hevin protein expression was increased in the nucleus accumbens after withdrawal followed by a ethanol challenge. The role of hevin in AUD was determined using an RNA interference strategy to downregulate hevin expression in nucleus accumbens astrocytes, which led to increased ethanol consumption. Additionally, ethanol challenge after withdrawal increased hevin levels in blood plasma. Altogether, these results support a novel role for hevin in the neurobiology of AUD. [ABSTRACT FROM AUTHOR]

Background: Secreted protein acidic and rich in cysteine-like 1 (SPARCL1) was a kind of extracellular matrix glycoprotein. SPARCL1 was strongly inhibited in most cancers. However, the potential functions of SPARCL1 in the pan-cancer cohort have not been widely studied.Methods: We evaluated the transcriptional level and the prognostic value of SPARCL1 in 33 types of cancer and revealed the relationship between genetic alterations of SPARCL1 and the tumor mutation burden. Meanwhile, we assessed the correlations between SPARCL1 and tumor-infiltrating lymphocytes across cancers.Results: The transcriptional level of SPARCL1 was inhibited in most cancers. Although SPARCL1 was down-regulated in most cancers, SPARCL1 might play a protective or detrimental role in different cancers. We demonstrated that mutation count was elevated in the altered SPARCL1 group in several cancers. Additionally, we found a significant positive correlation between SPARCL1 and macrophage infiltration levels in most cancers. Especially, marker sets of M2 macrophages were strongly related to SPARCL1 in cholangiocarcinoma, colon adenocarcinoma, rectum adenocarcinoma, and pancreatic adenocarcinoma.Conclusion: Our study found that SPARCL1 might work as a biomarker for prognosis and immune infiltration in pan-cancer analysis.

ObjectivesRecent studies found that secreted protein acidic and rich in cysteine-like protein 1 (Sparcl1) could inhibit lipid droplets accumulation by peroxisome proliferator-activated receptor-gamma (PPARγ) signal pathway. However, the associations of serum Sparcl1 level with lipids profiles and other metabolic phenotypes remain unknown in human population study.MethodsWe determined serum Sparcl1 using sandwich enzyme-linked immunosorbent assays among 1750 adults aged 40 years and older from a community in Shanghai, China. Generalized linear regression models were used to evaluate the association between Sparcl1 and metabolic measures. Multivariable-adjusted logistic regression analyses were performed to evaluate the relationship of serum Sparcl1 with prevalent dyslipidemia.ResultsWith the increment of serum Sparcl1, participants tended to have lower level of triglycerides, and higher level of high-density lipoprotein cholesterol (all P for trend < 0.01). No significant associations between serum Sparcl1 and glucose, blood pressure, or body size were observed. The generalized linear regression models suggested that per standard deviation (SD) increment of serum Sparcl1 was significantly inversely associated with triglycerides (β= -0.06, P=0.02). The prevalence of dyslipidemia decreased across the sparcl1 quartiles (P for trend 0.05).ConclusionSerum Sparcl1 was significantly associated with decreased risk of prevalent dyslipidemia in Chinese population. Further studies are warranted to confirm this association.

Important candidate genes that regulate lipid metabolism have the potential to increase the content of intramuscular fat (IMF) and improve meat quality. Secreted protein acidic and rich in cysteine like 1(SPARCL1) is a secreted glycoprotein with important physiological functions and is involved in the proliferation and differentiation of various cells. However, the role of the SPARCL1 gene in sheep preadipocytes and its regulatory mechanism is still unclear. In this study, we explored the effect of SPARCL1 on the proliferation and differentiation of sheep preadipocytes. The results showed that the expression level of the SPARCL1 gene is higher in fat tissue than in other tissues, and the gene was significantly increased on the 6th day of preadipocyte differentiation. In the preadipocyte proliferation stage, interference of SPARCL1 gene reduced cell viability and increased cell apoptosis. In preadipocyte differentiation stage, SPARCL1 overexpression significantly inhibited lipid droplets accumulation and triglyceride content by increasing Wnt10b, Fzd8, IL6, and β-catenin and inhibiting PPARγ, C/EBPα, LPL, and IGF1 genes expression, whereas SPARCL1 deficiency significantly promoted cell differentiation by inhibiting β-catenin and increasing GSK3β, PPARγ, C/EBPα, and LPL. The results of this study suggest that SPARCL1 plays a negative role during preadipocyte differentiation and may become a novel target for regulating preadipocyte differentiation and improving IMF. Abbreviations: IMF: Intramuscular fat SPARCL1: Secreted protein acidic and rich in cysteine like 1 PPARγ: Peroxisome proliferator-activated receptor γ C/EBPα: CCAAT/enhancer-binding protein-α LPL: Lipoprotein lipase IGF1: Insulin-like growth factor 1 Wnt10b: Wnt family member 10B Fzd8: Frizzled class receptor 8 IL6: Interleukin 6 β-catenin: Catenin beta interacting protein 1 GSK3β: Glycogen synthase kinase 3 beta LRP5/6: Low-density lipoprotein receptor-related protein 5/6

Objective: Esophageal squamous cell carcinoma (ESCC) presents high morbidity and mortality. It was demonstrated that blood-derived vesicles can facilitate ESCC development and transmit regulating signals. However, the molecular mechanism of vesicle miRNA secreted by tumor cells affecting ESCC progression has not been explored.Methods: The mRNA-related signaling pathways and differentially expressed genes were screened out in TCGA dataset. The levels of miRNA-105-5p and SPARCL1 were determined by qRT-PCR. Protein level determination was processed using Western blot. The interaction between the two genes was verified with the dual-luciferase method. A transmission electron microscope was utilized to further identify extracellular vesicles (EVs), and co-culture assay was performed to validate the intake of EVs. In vitro experiments were conducted to evaluate cell function changes in ESCC. A mice tumor formation experiment was carried out to observe tumor growth in vivo.Results: MiRNA-105-5p expression was increased in ESCC, while SPARCL1 was less expressed. MiRNA-105-5p facilitated cell behaviors in ESCC through targeting SPARCL1 and regulating the focal adhesion kinase (FAK)/Akt signaling pathway. Blood-derived external vesicles containing miRNA-105-5p and EVs could be internalized by ESCC cells. Then, miRNA-105-5p could be transferred to ESCC cells to foster tumorigenesis as well as cell behaviors.Conclusion: EV-carried miRNA-105-5p entered ESCC cells and promoted tumor-relevant functions by mediating SPARCL1 and the FAK/Akt signaling pathway, which indicated that the treatment of ESCC via serum EVs might be a novel therapy and that miRNA-105-5p can be a molecular target for ESCC therapy.

During mammalian brain development, how different astrocytes are specified from progenitor cells is not well understood. In particular, whether astrocyte progenitor cells (APCs) start as a relatively homogenous population or whether there is early heterogeneity remains unclear. Here, we have dissected subpopulations of embryonic mouse forebrain progenitors using single-cell transcriptome analyses. Our sequencing data revealed two molecularly distinct APC subgroups at the start of gliogenesis from both dorsal and ventral forebrains. The two APC subgroups were marked, respectively, by specific expression of Sparc and Sparcl1, which are known to function in mature astrocytes with opposing activities for regulating synapse formation. Expression analyses showed that SPARC and SPARCL1 mark APC subgroups that display distinct temporal and spatial patterns, correlating with major waves of astrogliogenesis during development. Our results uncover an early molecular divergence of APCs in the mammalian brain and provide a useful transcriptome resource for the study of glial cell specification. [ABSTRACT FROM AUTHOR]

Objective: Esophageal squamous cell carcinoma (ESCC) presents high morbidity and mortality. It was demonstrated that blood-derived vesicles can facilitate ESCC development and transmit regulating signals. However, the molecular mechanism of vesicle miRNA secreted by tumor cells affecting ESCC progression has not been explored. Methods: The mRNA-related signaling pathways and differentially expressed genes were screened out in TCGA dataset. The levels of miRNA-105-5p and SPARCL1 were determined by qRT-PCR. Protein level determination was processed using Western blot. The interaction between the two genes was verified with the dual-luciferase method. A transmission electron microscope was utilized to further identify extracellular vesicles (EVs), and co-culture assay was performed to validate the intake of EVs. In vitro experiments were conducted to evaluate cell function changes in ESCC. A mice tumor formation experiment was carried out to observe tumor growth in vivo. Results: MiRNA-105-5p expression was increased in ESCC, while SPARCL1 was less expressed. MiRNA-105-5p facilitated cell behaviors in ESCC through targeting SPARCL1 and regulating the focal adhesion kinase (FAK)/Akt signaling pathway. Blood-derived external vesicles containing miRNA-105-5p and EVs could be internalized by ESCC cells. Then, miRNA-105-5p could be transferred to ESCC cells to foster tumorigenesis as well as cell behaviors. Conclusion: EV-carried miRNA-105-5p entered ESCC cells and promoted tumor-relevant functions by mediating SPARCL1 and the FAK/Akt signaling pathway, which indicated that the treatment of ESCC via serum EVs might be a novel therapy and that miRNA-105-5p can be a molecular target for ESCC therapy. [ABSTRACT FROM AUTHOR]

• Two forms of protein hevin, differentially glycosylated, are detected in human brain: 130 kDa and 100 kDa. • Hevin expression is higher in prefrontal cortex compared to hippocampus, caudate and cerebellum. • Hevin is strongly expressed in membrane-enriched fraction compared to cytosolic fraction. • Hevin protein is detected in cerebrospinal fluid and serum, but absent from any blood cell type. Hevin is a matricellular glycoprotein that plays important roles in neural developmental processes such as neuronal migration, synaptogenesis and synaptic plasticity. In contrast to other matricellular proteins whose expression decreases when development is complete, hevin remains highly expressed, suggesting its involvement in adult brain function. In vitro studies have shown that hevin can have different post-translational modifications. However, the glycosylation pattern of hevin in the human brain remains unknown, as well as its relative distribution and localization. The present study provides the first thorough characterization of hevin protein expression by Western blot in postmortem adult human brain. Our results demonstrated two major specific immunoreactive bands for hevin: an intense band migrating around 130 kDa, and a band migrating around 100 kDa. Biochemical assays revealed that both hevin bands have a different glycosylation pattern. Subcellular fractionation showed greater expression in membrane-enriched fraction than in cytosolic preparation, and a higher expression in prefrontal cortex (PFC) compared to hippocampus (HIP), caudate nucleus (CAU) and cerebellum (CB). We confirmed that a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS4) and matrixmetalloproteinase 3 (MMP-3) proteases digestion led to an intense double band with similar molecular weight to that described as SPARC-like fragment (SLF). Finally, hevin immunoreactivity was also detected in human astrocytoma, meningioma, cerebrospinal fluid and serum samples, but was absent from any blood cell type. [ABSTRACT FROM AUTHOR]

Single-cell transcriptome analysis has provided detailed insights into the ecosystem of liver cancer. However, the changes of the cellular and molecular components of liver tumors in comparison with normal livers have not been described at single-cell level. Here, we performed an integrative single-cell analysis of both normal livers and liver cancers. Principal component analysis was firstly performed to delineate the cell lineages in liver tissues. Differential gene expression within major cell types were then analyzed between tumor and normal samples, thus resolved the cell type-specific molecular alterations in liver cancer development. Moreover, a comparison between liver cancer derived versus normal liver derived cell components revealed that two subpopulations of fibroblasts were exclusively expanded in liver cancer tissues. By further defining subpopulation-specific gene signatures, characterizing their spatial distribution in tumor tissues and investigating their clinical significance, we found that the SPARCL1 positive fibroblasts, representing a group of tumor vessel associated fibroblasts, were related to reduced vascular invasion and prolonged survival of liver cancer patients. Through establishing an in-vitro endothelial-to-mesenchymal transition model, we verified the conversion of the fetal liver sinusoidal endothelial cells into the fibroblast-like cells, demonstrating a possible endothelial cell origination of the SPARCL1 positive fibroblasts. Our study provides new insights into the cell atlas alteration, especially the expanded fibroblasts in liver cancers.

Abstract Background Malignant growth and metastasis of gastrointestinal stromal tumors (GIST) occur in some patients even during the course of treatment, but their mechanisms remains poorly understand at the molecular level so far. Methods Profiles of protein expression in gastric GIST tissues were explored using protein microarray analysis, down-regulation of SPARCL1 (secreted protein acidic and rich in cysteine-like protein 1) was validated by RT-qPCR, western blot and immunohistochemistry. The effect of specific shRNA-induced SPARCL1 downregulation on the biological traits of GIST 882 cell was investigated. We then employed a mouse xenograft model to investigate whether the low-expression of SPARCL1 impact the metastasis ability of GIST cells in vivo. Results SPARCL1 was significantly downregulated in the gastric GIST with high-grade malignance as compared with low-grade malignance, its expression was closely correlated with tumor size, mitotic index, distant metastasis at the time of initial diagnosis and tumor progression of GIST (P

Secreted protein acidic and rich in cysteines-like 1 (SPARCL1) is implicated in tumor progression and considered as a tumor suppressor. Aim of the study is to investigate the role of SPARCL1 in the regulation of tumor biology. SPARCL1 expression in human cervical cells was determined through western blot and RT-PCR. The effects of SPARCL1 overexpression on cell proliferation, migration and invasion were evaluated through CCK8 assay, colony formation assay, Wound healing assay and Transwell assay, respectively. The gain function of Secreted phosphor protein 1 (SPP1) was also evaluated in these cell functions. We observed that SPARCL1 expression at protein levels and transcription levels was lower in HeLa cells than that in Ect1/E6E7 cells. When SPARCL1 was overexpressed in HeLa cells, cell proliferation, migration and invasion were greatly repressed. Additionally, SPARCL1 overexpression markedly downregulated SPP1 expression at transcription levels. Mechanistical study revealed that SPP1 overexpression could greatly counteract the effects of SPARCL1 overexpression on the aforementioned cell processes and inhibit the phosphorylation of focal adhesion kinase (FAK) and extracellular regulated protein kinases (ERK). Our findings indicated that HeLa cells overexpressing SPARCL1 showed weaker abilities of proliferation, migration and invasion, and its effects could be neutralized by SPP1 overexpression possibly via FAK/ERK pathway. The relationship of SPARCL1 and SPP1 could help us to further understand the pathogenesis of cervical cancer and SPARCL1/SPP1 could be beneficial therapeutic targets in cervical cancer. [ABSTRACT FROM AUTHOR]

Background/Aims: Secreted protein acidic and rich in cysteines-like 1 (SPARCL1) is abnormally expressed in gastrointestinal (GI) malignancies. However, the correlation between SPARCL1 expression and the prognosis of patients remains unknown. Therefore, we performed a meta-analysis to investigate the potential value of SPARCL1 as a prognostic predictive marker for GI malignancies. Methods: The PubMed, Embase, EBSCO, CNKI, and Wanfang databases were systematically searched for studies examining SPARCL1 and clinicopathological features, including the prognoses of patients. Hazard ratios (HRs) and odds ratios (ORs) from individual studies were calculated and pooled using a random-effects or fix-effects model. Heterogeneity and publication bias analyses were performed. Results: Data from 8 studies, including a total of 2,356 patients, were summarized. The expression of SPARCL1 suggested a better prognosis (HR=0.57, 95% CI: 0.445-0.698, P=0.000) and was associated with clinicopathological features of GI malignancies, including distant metastasis (OR=0.44, 95% CI: 0.23-0.85, P=0.014), lymph node metastasis (OR=0.56, 95% CI: 0.39–0.81, P=0.002) and tumor differentiation (OR=2.21, 95% CI: 1.82–2.69, P=0.000). Subgroup analyses based on cancer type revealed that the expression of SPARCL1 had no effect on lymph node metastasis in colorectal cancer, and it did not influence tumor differentiation in gastric cancer. Egger’s test showed no evidence of publication bias (all P>0.05). Conclusion: SPARCL1 could be a novel prognostic predictive factor for GI malignancies. The expression of SPARCL1 could influence the clinicopathological features of GI malignancies. Further large-scale studies are essential to confirm SPARCL1’s prognostic predictive value, and more fundamental experimental studies are needed to illustrate the mechanisms.

Introduction: Embryo implantation depends on trophoblast cells migration and invasion. Abnormal function of trophoblast cells could result in many pregnancy complications. Secreted protein acidic and rich in cysteine like-1 (SPARCL1) has been reported to inhibit cell migration and tumor invasion. This study aimed to explore the role of SPARCL1 in trophoblast functions.Methods: Villous specimens were obtained from 31 women with spontaneous abortion and 31 women with normal early pregnancy to determine the expression of SPARCL1. HTR8/SVneo cells and JAR cells were transfected with pIRES2-EGFP-SPARCL1 vectors and control vectors. The proliferation assay and scratch-wound assay were performed. Quantitative polymerase chain reaction (qPCR) and western blotting were performed to assess epithelial mesenchymal transition (EMT)-related molecules including MMP2, MMP3, N-cadherin, E-cadherin and vimentin. Extracellular signal-regulated kinase (ERK) phosphorylation activity and AP-1 expression in HTR8/SVneo cells following multi-scratching were detected using above assays.Results: The mRNA and protein levels of SPARCL1 were significantly higher in the abortion group than in the normal pregnancy group. After transfection, there was no difference of cell viability between the SPARCL1-overexpression group and control vector group. However, the migration distance and area were reduced and the abundances of EMT related molecules were changed by SPARCL1 overexpression when compared with controls. Lower ERK phosphorylation activity and decreased Fos and Jun expressions were noted at high level of SPARCL1.Conclusion: Restrained migration and invasion were noted in trophoblast cells with SPARCL1 overexpression, which might affect embryo implantation and placenta development. It could be involved in the pathogenesis of spontaneous abortion. [ABSTRACT FROM AUTHOR]

As an extracellular matrix protein, secreted protein acidic and rich in cysteine (SPARC)-like 1 (SPARCL1) is involved in various cell functions. It was previously implicated in bovine skeletal muscle-derived satellite cell (MDSC) differentiation; however, the underlying mechanism remains unknown. In this study, immunoprecipitation and mass spectrometry revealed that integrin β1 (ITGB1) combines with SPARCL1. Further, co-immunoprecipitation demonstrated that SPARCL1 interacts with ITGB1. Cell scratch assays explored the influence of SPARCL1 on MDSC migration through ITGB1. In addition, desmin staining for myotube fusion rate and MyoD protein expression results showed that SPARCL1 promotes MDSC early differentiation through ITGB1. Furthermore, Western blotting results demonstrated that SPARCL1 regulates the expression of p-FAK, p-paxillin, vinculin, Cdc42, and Arp2/3 through ITGB1. These findings indicate that SPARCL1 may influence bovine MDSC migration and differentiation through an ITGB1-mediated cell signaling pathway. Herein, we elucidated the mechanism through which SPARCL1 affects MDSC differentiation. Our results provide insight into the molecular mechanism of muscle development and may in the future facilitate skeletal muscle regeneration and treatment.

Endometriotic cells exhibit a notable degree of invasiveness and some characteristics of tissue remodeling underlying lesion formation. In this regard, do matrix metalloproteinases 14 (MMP14) and other related genes such as SPARC-like protein 1 (SPARCL1), caveolin 2 (CAV2), and clusterin (CLU) exert any significant influence in the processes of endometriosis development and pathophysiology is not apparent. We aim to assess whether these genes could serve as potential diagnostic biomarkers in endometriosis. Microarray-based gene expression analysis was performed on total RNA extracted from endometriotic tissue samples treated with and without gonadotropin-releasing hormone agonist (GnRHa). The GnRHa untreated patients were considered the control group. The validation of genes was performed using quantitative real-time polymerase chain reaction (qRT-PCR). qRT-PCR analysis showed significant downregulation in the expression of MMP14 (p = 0.024), CAV2 (p = 0.017), and upregulation of CLU (p = 0.005) in endometriosis patients treated with GnRHa. SPARCL1 did not show any significant (p = 0.30) change in the expression compared to the control group. These data have the potential to contribute to the comprehension of the molecular pathways implicated in the remodeling of the extracellular matrix, which is a vital step for the physiology of the endometrium. Based on the result, it is concluded that changes in the expression of MMP14, CAV2, and CLU post-treatment imply their role in the pathophysiology of endometriosis and may serve as a potential diagnostic biomarker of endometriosis in response to GnRHa treatment in patients with ovarian endometrioma. [Display omitted] [ABSTRACT FROM AUTHOR]

Cervical cancer is the fourth most common malignancy among women worldwide, and continued research to discover biomarkers or therapeutic targets will aid early diagnosis and treatment of this cancer. Here, we investigated novel cervical cancer biomarkers using integrated analysis of high-throughput sequencing data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. We have identified nine genes of interest that appear to be involved in cervical cancer development: SPARCL1, SYCP2, KIF4A, PRC1, TOP2A, LAMP3, KIF20A, MCM2, and APOBEC3B. Furthermore, gene ontology (GO) and co-expression analysis of these differentially expressed genes indicated that SPARCL1 may play a core role in cervical cancer development. Further, we analyzed the expression of these nine genes during the progression of cervical cancer, and found that SPARCL1 is also related to precancerous lesions and migration processes during cervical cancer pathogenesis. Finally, we validated these observations by investigating SPARCL1 expression in cervical cancer tissue and serum samples. The diagnostic specificity of serum SPARCL1 in cervical cancer occurrence was also compared with other high incidence diseases. All of these data indicate that SPARCL1 may be a novel cancer predictive marker and a potential therapeutic target for tumor development and progression in cervical cancer. [ABSTRACT FROM AUTHOR]

Background/Aims: Secreted protein acidic and rich in cysteines-like 1 (SPARCL1) is abnormally expressed in gastrointestinal (GI) malignancies. However, the correlation between SPARCL1 expression and the prognosis of patients remains unknown. Therefore, we performed a metaanalysis to investigate the potential value of SPARCL1 as a prognostic predictive marker for GI malignancies. Methods: The PubMed, Embase, EBSCO, CNKI, and Wanfang databases were systematically searched for studies examining SPARCL1 and clinicopathological features, including the prognoses of patients. Hazard ratios (HRs) and odds ratios (ORs) from individual studies were calculated and pooled using a random-effects or fix-effects model. Heterogeneity and publication bias analyses were performed. Results: Data from 8 studies, including a total of 2,356 patients, were summarized. The expression of SPARCL1 suggested a better prognosis (HR=0.57, 95% CI: 0.445-0.698, P=0.000) and was associated with clinicopathological features of GI malignancies, including distant metastasis (OR=0.44, 95% CI: 0.23-0.85, P=0.014), lymph node metastasis (OR=0.56, 95% CI: 0.39-0.81, P=0.002) and tumor differentiation (OR=2.21, 95% CI: 1.82-2.69, P=0.000). Subgroup analyses based on cancer type revealed that the expression of SPARCL1 had no effect on lymph node metastasis in colorectal cancer, and it did not influence tumor differentiation in gastric cancer. Egger's test showed no evidence of publication bias (all P>0.05). Conclusion: SPARCL1 could be a novel prognostic predictive factor for GI malignancies. The expression of SPARCL1 could influence the clinicopathological features of GI malignancies. Further large-scale studies are essential to confirm SPARCL1's prognostic predictive value, and more fundamental experimental studies are needed to illustrate the mechanisms. [ABSTRACT FROM AUTHOR]

The geniculate ganglion (GG) contains visceral and somatic sensory neurons of the facial nerve. In this study, the number and cell size of sensory neurons in the human GG were investigated. The estimated number of GG neurons ranged from 1,580 to 2,561 (mean ± SD = 1,960 ± 364.6). The cell size of GG neurons ranged from 393.0 to 2,485.4 μm2 (mean ± SD = 1,067.4 ± 99.5 μm2). Sensory neurons in the GG were significantly smaller in size than those in the dorsal root (range = 326.6-5343.4 μm2, mean ± SD = 1,683.2 ± 203.8 μm2) or trigeminal ganglia (range = 349.6-4,889.28 μm2, mean ± SD = 1,529.0 ± 198.48 μm2). Sensory neurons had similar cell body sizes in the GG and nodose ganglion (range = 357.2-3,488.33 μm2, mean ± SD = 1,160.4 ± 156.61 μm2). These findings suggest that viscerosensory neurons have smaller cell bodies than somatosensory neurons. In addition, immunohistochemistry for several neurochemical substances was performed on the human GG. In the ganglion, sensory neurons were mostly immunoreactive for secreted protein, acidic and rich in cysteine-like 1 (94.3%). One third of GG neurons showed vesicular glutamate transporter 2 immunoreactivity (31.3%). Only 7.3% of GG neurons were immunoreactive for transient receptor potential cation channel subfamily V member 1. Sensory neurons in the human GG may respond to gustatory, nociceptive, and/or mechanoreceptive stimuli from tongues, soft palates, and external auditory canals. [ABSTRACT FROM AUTHOR]

SPARC-like protein 1 (SPARCL1), a member of the SPARC family, is downregulated in various tumors. In the present study, the expression and localization of SPARCL1 were analyzed in a wide range of nontumorous and neoplastic pancreatic tissues by quantitative reverse transcription-polymerase chain reaction, laser capture microdissection, microarray analysis, and immunohistochemistry. For functional analysis, proliferation and invasion assays were used in cultured pancreatic cancer cells. Pancreatic ductal adenocarcinoma (PDAC) and other pancreatic neoplasms exhibited increased SPARCL1 mRNA levels compared to those of the normal pancreas. SPARCL1 mRNA levels were low to absent in microdissected and cultured pancreatic cancer cells, and promoter demethylation increased SPARCL1 levels only slightly in three of eight cell lines. SPARCL1 was observed in small capillaries in areas of inflammation/tumor growth and in some islet cells. In PDAC, 15.4% of vessels were SPARCL1-positive. In contrast, the percentage of SPARCL1-positive vessels was higher in chronic pancreatitis and benign and borderline pancreatic tumors. Recombinant SPARCL1 inhibited pancreatic cancer cell invasion and exerted moderate growth-inhibitory effects. In conclusion, SPARCL1 expression in pancreatic tissues is highly correlated with level of vascularity. Its antiinvasive effects and reduced expression in metastasis indicate tumor-suppressor function.

The matricellular proteins, secreted protein acidic and rich in cysteine (SPARC) and SPARC-like 1 (SPARCL1), are produced by astrocytes and control excitatory synaptogenesis in the central nervous system. While SPARCL1 directly promotes excitatory synapse formation in vitro and in the developing nervous system in vivo, SPARC specifically antagonizes the synaptogenic actions of SPARCL1. We hypothesized these proteins also help maintain existing excitatory synapses in adult hosts, and that local inflammation in the spinal cord alters their production in a way that dynamically modulates motor synapses and impacts the severity of paralysis during experimental autoimmune encephalomyelitis (EAE) in mice. Using a spontaneously remitting EAE model, paralysis severity correlated inversely with both expression of synaptic proteins and the number of synapses in direct contact with the perikarya of motor neurons in spinal grey matter. In both remitting and non-remitting EAE models, paralysis severity also correlated inversely with sparcl1:sparc transcript and SPARCL1:SPARC protein ratios directly in lumbar spinal cord tissue. In vitro, astrocyte production of both SPARCL1 and SPARC was regulated by T cell-derived cytokines, causing dynamic modulation of the SPARCL1:SPARC expression ratio. Taken together, these data support a model whereby proinflammatory cytokines inhibit SPARCL1 and/or augment SPARC expression by astrocytes in spinal grey matter that, in turn, cause either transient or sustained synaptic retraction from lumbar spinal motor neurons thereby regulating hind limb paralysis during EAE. Ongoing studies seek ways to alter this SPARCL1:SPARC expression ratio in favor of synapse reformation/maintenance and thus help to modulate neurologic deficits during times of inflammation. This could identify new astrocyte-targeted therapies for diseases such as multiple sclerosis.

Matricellular proteins are secreted, nonstructural proteins, involved in the mediation of molecular interactions between cells and extracellular microenvironment. They include several, structurally unrelated, members and their homologs. Among these a particularly interesting one is SPARCL1 due to its potential interactions in tumor biology. SPARCL1 is a secreted glycoprotein, belonging to SPARC family of matricellular proteins. It is implicated in the regulation of cell adhesion, migration, and proliferation. SPARCL1 is expressed in physiological context, both during embryogenesis and in adult life during tissue remodeling. Its diverse expression pattern in different forms of human cancers has suggested it may play different roles in tumor biology, as both oncogene and tumor suppressor, based on tumor type. Aim of this review is to critically revise current knowledges about the role, played by SPARCL1, in physiological and pathological contexts and highlight its role as a key-gene in the regulation of tumor biology. [ABSTRACT FROM AUTHOR]

Secreted protein, acidic and rich in cysteine-like 1 (SPARCL1) is a member of the osteonectin family of proteins. In this study, immunohistochemistry for SPARCL1 was performed to obtain its distribution in the human brainstem, cervical spinal cord, and sensory ganglion. SPARCL1-immunoreactivity was detected in neuronal cell bodies including perikarya and proximal dendrites, and the neuropil. The motor nuclei of the IIIrd, Vth, VIth, VIIth, IXth, Xth, XIth, and XIIth cranial nerves and spinal nerves contained many SPARCL1-immunoreactive (-IR) neurons with medium-sized to large cell bodies. Small and medium-sized SPARCL1-IR neurons were distributed in sensory nuclei of the Vth, VIIth, VIIIth, IXth, and Xth cranial nerves. In the medulla oblongata, the dorsal column nuclei also had small to medium-sized SPARCL1-IR neurons. In addition, SPARCL1-IR neurons were detected in the nucleus of the trapezoid body and pontine nucleus within the pons and the arcuate nucleus in the medulla oblongata. In the cervical spinal cord, the ventral horn contained some SPARCL1-IR neurons with large cell bodies. These findings suggest that SPARCL1-containing neurons function to relay and regulate motor and sensory signals in the human brainstem. In the dorsal root (DRG) and trigeminal ganglia (TG), primary sensory neurons contained SPARCL1-immunoreactivity. The proportion of SPARCL1-IR neurons in the TG (mean ± SD, 39.9 ± 2.4%) was higher than in the DRG (30.6 ± 2.1%). SPARCL1-IR neurons were mostly medium-sized to large (mean ± SD, 1494.5 ± 708.3 μm2; range, 320.4–4353.4 μm2) in the DRG, whereas such neurons were of various cell body sizes in the TG (mean ± SD, 1291.2 ± 532.8 μm2; range, 209.3–4326.4 μm2). There appears to be a SPARCL1-containing sensory pathway in the ganglion and brainstem of the spinal and trigeminal nervous systems. [ABSTRACT FROM PUBLISHER]

Secreted protein acidic and rich in cysteines-like protein 1 (SPARCL1) has been implicated in tumor initiation, formation, and progression of various cancers, yet its role in hilar cholangiocarcinoma remains largely uncharacterized. In the present study, tissue microarrays containing resected hilar cholangiocarcinoma specimens from 92 patients were used to evaluate the expression of SPARCL1 protein by immunohistochemistry (IHC). In vitro assays were used to determine the effect of SPARCL1 overexpression on cell growth and migration. Loss of SPARCL1 expression was observed in 46 (50.0 %) of the 92 primary tumors. SPARCL1 expression is inversely associated with poorly or undifferentiation specimens ( P = 0.030) in addition to lymph node metastasis ( P = 0.047). Survival analysis demonstrated that SPARCL1 is an independent factor in predicting the outcome of patients with hilar cholangiocarcinoma. SPARCL1 overexpression suppressed tumor cell migration in vitro by inhibiting MMP-9, MMP-2, Vimentin, and Fibronectin expression, whereas did not inhibit cell proliferation in vitro. Our results suggest that loss of SPARCL1 is involved in the tumorigenesis of hilar cholangiocarcinoma and may serve as a novel molecular biomarker for patients' outcome. [ABSTRACT FROM AUTHOR]

The matricellular proteins, secreted protein acidic and rich in cysteine (SPARC) and SPARC-like 1 (SPARCL1), are produced by astrocytes and control excitatory synaptogenesis in the central nervous system. While SPARCL1 directly promotes excitatory synapse formation in vitro and in the developing nervous system in vivo, SPARC specifically antagonizes the synaptogenic actions of SPARCL1.We hypothesized these proteins also help maintain existing excitatory synapses in adult hosts, and that local inflammation in the spinal cord alters their production in a way that dynamically modulates motor synapses and impacts the severity of paralysis during experimental autoimmune encephalomyelitis (EAE) in mice. Using a spontaneously remitting EAE model, paralysis severity correlated inversely with both expression of synaptic proteins and the number of synapses in direct contact with the perikarya of motor neurons in spinal gray matter. In both remitting and non-remitting EAE models, paralysis severity also correlated inversely with sparcl1:sparc transcript and SPARCL1:SPARC protein ratios directly in lumbar spinal cord tissue. In vitro, astrocyte production of both SPARCL1 and SPARC was regulated by T cell-derived cytokines, causing dynamic modulation of the SPARCL1:SPARC expression ratio. Taken together, these data support a model whereby proinflammatory cytokines inhibit SPARCL1 and/or augment SPARC expression by astrocytes in spinal gray matter that, in turn, cause either transient or sustained synaptic retraction from lumbar spinal motor neurons thereby regulating hind limb paralysis during EAE. Ongoing studies seek ways to alter this SPARCL1:SPARC expression ratio in favor of synapse reformation/maintenance and thus help to modulate neurologic deficits during times of inflammation. This could identify new astrocyte-targeted therapies for diseases such as multiple sclerosis. [ABSTRACT FROM AUTHOR]

We have used proteomic fingerprinting to investigate diagnosis of Alzheimer's disease (AD). Samples of lumbar cerebrospinal fluid (CSF) from clinically-diagnosed AD cases (n = 33), age-matched controls (n = 20), and mild cognitive impairment (MCI) patients (n = 10) were used to obtain proteomic profiles, followed by bioinformatic analysis that generated a set of potential biomarkers in CSF samples that could discriminate AD cases from controls. The identity of the biomarker ions was determined using mass spectroscopy. The panel of seven peptide biomarker ions was able to discriminate AD patients from controls with a median accuracy of 95% (sensitivity 85%, specificity 97%). When this model was applied to an independent blind dataset from MCI patients, the intensity of signals was intermediate between the control and AD patients implying that these markers could potentially predict patients with early neurodegenerative disease. The panel were identified, in order of predictive ability, as SPARC-like 1 protein, fibrinogen alpha chain precursor, amyloid-β, apolipoprotein E precursor, serum albumin precursor, keratin type I cytoskeletal 9, and tetranectin. The 7 ion ANN model was further validated using an independent cohort of samples, where the model was able to classify AD cases from controls with median accuracy of 84.5% (sensitivity 93.3%, specificity 75.7%). Validation by immunoassay was performed on the top three identified markers using the discovery samples and an independent sample cohort which was from postmortem confirmed AD patients (n = 17). [ABSTRACT FROM AUTHOR]

We investigated whether SPARCL1 played an essential role in tumor initiation, formation and progression of colorectal carcinomas. In this study, we examined expression of SPARCL1 protein in the normal colorectal mucosa, adjacent normal mucosa and primary and lymph node metastases from colorectal cancer patients. In matched patients, we found that SPARCL1 was negative in the distant normal colorectal mucosa, weakly expressed in the adjacent normal mucosa, strongly expressed in primary colorectal adenocarcinomas and slightly expressed in their lymph node metastases. A similar pattern was observed in the SPARCL1 expression from our series of non-matched colorectal cancer patients. The strongest expression and highest frequency of the SPARCL1 protein were found in the primary cancers. Interestingly, in the primary tumors, the frequency of SPARCL1 expression was significantly increased from the Dukes' A to Dukes' B tumors and then decreased gradually from the Dukes' B to C and D tumors. There was no difference in the intensity of SPARCL1 expression between the central areas and invasion margins of the primary tumors. Moreover, the SPARCL1 protein was more strongly expressed in the highly differentiated tumors than the lower differentiated ones. The patients with positive expression of SPARCL1 in their tumors had worse prognosis than the patients with SPARCL1-negative ones, even after the analyses by Multivariate and Interaction method. Expression of SPARCL1 protein might be a valuable biomarker for early diagnosis in colorectal cancers and further predicting patients' prognosis. [ABSTRACT FROM AUTHOR]