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The Journal of Clinical Investigation Oct 2023The comprehensive assessment of long-term effects of reducing intake of energy (CALERIE-II; NCT00427193) clinical trial established that caloric restriction (CR) in...
The comprehensive assessment of long-term effects of reducing intake of energy (CALERIE-II; NCT00427193) clinical trial established that caloric restriction (CR) in humans lowers inflammation. The identity and mechanism of endogenous CR-mimetics that can be deployed to control obesity-associated inflammation and diseases are not well understood. Our studies have found that 2 years of 14% sustained CR in humans inhibits the expression of the matricellular protein, secreted protein acidic and rich in cysteine (SPARC), in adipose tissue. In mice, adipose tissue remodeling caused by weight loss through CR and low-protein diet feeding decreased, while high-fat diet-induced (HFD-induced) obesity increased SPARC expression in adipose tissue. Inducible SPARC downregulation in adult mice mimicked CR's effects on lowering adiposity by regulating energy expenditure. Deletion of SPARC in adipocytes was sufficient to protect mice against HFD-induced adiposity, chronic inflammation, and metabolic dysfunction. Mechanistically, SPARC activates the NLRP3 inflammasome at the priming step and downregulation of SPARC lowers macrophage inflammation in adipose tissue, while excess SPARC activated macrophages via JNK signaling. Collectively, reduction of adipocyte-derived SPARC confers CR-like metabolic and antiinflammatory benefits in obesity by serving as an immunometabolic checkpoint of inflammation.
Topics: Animals; Humans; Mice; Adipose Tissue; Diet, High-Fat; Inflammasomes; Inflammation; Mice, Inbred C57BL; NLR Family, Pyrin Domain-Containing 3 Protein; Obesity; Osteonectin
PubMed: 37781916
DOI: 10.1172/JCI169173 -
Experimental Cell Research Aug 2023Fibrotic scar is a severe side effect of trabeculectomy, resulting in unsatisfactory outcomes for glaucoma surgery. Accumulating evidence showed human Tenon's...
BACKGROUND
Fibrotic scar is a severe side effect of trabeculectomy, resulting in unsatisfactory outcomes for glaucoma surgery. Accumulating evidence showed human Tenon's fibroblasts (HTFs) play an important role in fibrosis formation. We previously reported that the aqueous level of secreted protein acidic and rich in cysteine (SPARC) was higher in the patients with primary angle closure glaucoma, which was associated with the failure of trabeculectomy. In this study, the potential effect and mechanism of SPARC in promoting fibrosis were explored by using HTFs.
METHODS
HTFs were employed in this study and examined under a phase-contrast microscope. Cell viability was determined by CCK-8. The expressions of SPARC-YAP/TAZ signaling and the fibrosis-related markers were examined with reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), Western blot, and immunofluorescence, subcellular fractionation was conducted to further determined the variation of YAP and phosphorylated YAP. The differential gene expressions were analyzed with RNA sequencing (RNAseq), followed by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses.
RESULTS
Exogenous SPARC induced HTFs-myofibroblast transformation, as evidenced by the increased expression of α-SMA, collagen I and fibronectin in both protein and mRNA levels. SPARC knockdown decreased the expressions of the above genes in TGF-β2-treated HTFs. KEGG analysis showed that the Hippo signaling pathway was mostly enriched. SPARC treatment increased the expressions of YAP, TAZ, CTGF and CYR61 as well as enhanced YAP translocation from cytoplasm to nucleus, and decreased the phosphorylation of YAP and LAST1/2, which was reversed by SPARC knockdown. Knockdown of YAP1 decreased the fibrosis-related markers, such as α-SMA, collagen I and Fibronectin, in SPARC-treated HTFs.
CONCLUSIONS
SPARC induced HTFs-myofibroblast transformation via activating YAP/TAZ signaling. Targeting SPARC-YAP/TAZ axis in HTFs might provide a novel strategy for inhibiting fibrosis formation after trabeculectomy.
Topics: Humans; Myofibroblasts; Fibronectins; Osteonectin; Fibroblasts; Collagen Type I; Fibrosis; Cells, Cultured
PubMed: 37225012
DOI: 10.1016/j.yexcr.2023.113649 -
Journal of Orthopaedic Surgery and... Oct 2023The aim of this study was to investigate whether Osteonectin/Secreted protein acidic and rich in cysteine (ON/SPARC) had a two-way dose-dependent regulatory effect on...
OBJECTIVE
The aim of this study was to investigate whether Osteonectin/Secreted protein acidic and rich in cysteine (ON/SPARC) had a two-way dose-dependent regulatory effect on osteoblast mineralization and its molecular mechanism.
METHODS
Initially, different concentrations of ON were added in osteoblasts, and the gene of bone sialoprotein (BSP), osteocalcin (OCN), osteopontin (OPN) and alkaline phosphatase (ALP) were detected using reverse-transcription quantitative polymerase chain reaction (RT-PCR). Secondly, based on the above results, the Optima and inhibitory concentration of ON for osteoblast mineralization were determined and regrouped, the Control group was also set up, and the gene detections of Collagen 1 (Col 1), Discoidin domain receptor 2 (DDR2) and p38 mitogen‑activated protein kinase were added using RT-PCR. In the third stage of the experiment, osteoblasts were pretreated with 0.4Mm ethyl-3,4-dihydroxybenzoate (DHB) (a specific inhibitor of collagen synthesis) for 3 h before adding the optima SPARC, the gene and protein expressions of OCN, OPN, BSP, ALP, DDR2, ALP, Col 1, DDR2 and P38 were detected by RT‑qPCR and western blot analysis, and the mineralized nodules were observed by alizarin red staining.
RESULTS
The results showed that the expression of OCN, OPN, BSP, ALP, DDR2, ALP, Col 1, DDR2 and P38 genes and proteins in osteoblasts were significantly enhanced by 1 ug/ml ON, 100 ug/ml ON or 1 ug/ml ON added with 3,4 DHB significantly inhibited the expressions of DDR2, P38 and the above-mentioned mineralization indexes, and significantly reduced the formation of mineralized nodules.
CONCLUSION
This study suggested that ON had a bidirectional dose-dependent regulatory effect on osteoblast mineralization, and the activation of P38 pathway by collagen binding to DDR2 was also an important molecular mechanism.
Topics: Humans; Osteonectin; Osteocalcin; Calcinosis; Integrin-Binding Sialoprotein; Collagen; Osteoblasts; Cell Differentiation; Osteogenesis
PubMed: 37807073
DOI: 10.1186/s13018-023-04250-1 -
Frontiers in Molecular Biosciences 2023Secreted protein acidic and rich in cysteine (SPARC), also termed osteonectin or BM-40, is a matricellular protein which regulates cell adhesion, extracellular matrix... (Review)
Review
Secreted protein acidic and rich in cysteine (SPARC), also termed osteonectin or BM-40, is a matricellular protein which regulates cell adhesion, extracellular matrix production, growth factor activity, and cell cycle. Although SPARC does not perform a structural function, it, however, modulates interactions between cells and the surrounding extracellular matrix due to its anti-proliferative and anti-adhesion properties. The overexpression of SPARC at sites, including injury, regeneration, obesity, cancer, and inflammation, reveals its application as a prospective target and therapeutic indicator in the treatment and assessment of disease. This article comprehensively summarizes the mechanism of SPARC overexpression in inflammation and tumors as well as the latest research progress of functional nanomaterials in the therapy of rheumatoid arthritis and tumors by manipulating SPARC as a new target. This article provides ideas for using functional nanomaterials to treat inflammatory diseases through the SPARC target. The purpose of this article is to provide a reference for ongoing disease research based on SPARC-targeted therapy.
PubMed: 37577749
DOI: 10.3389/fmolb.2023.1235428 -
Cell Communication and Signaling : CCS Mar 2024Heterotopic ossification (HO) is a pathological process in which ectopic bone develops in soft tissues within the skeletal system. Endochondral ossification can be... (Review)
Review
Heterotopic ossification (HO) is a pathological process in which ectopic bone develops in soft tissues within the skeletal system. Endochondral ossification can be divided into the following types of acquired and inherited ossification: traumatic HO (tHO) and fibrodysplasia ossificans progressiva (FOP). Nuclear transcription factor kappa B (NF-κB) signalling is essential during HO. NF-κB signalling can drive initial inflammation through interactions with the NOD-like receptor protein 3 (NLRP3) inflammasome, Sirtuin 1 (SIRT1) and AMP-activated protein kinase (AMPK). In the chondrogenesis stage, NF-κB signalling can promote chondrogenesis through interactions with mechanistic target of rapamycin (mTOR), phosphatidylinositol-3-kinase (PI3K)/AKT (protein kinase B, PKB) and other molecules, including R-spondin 2 (Rspo2) and SRY-box 9 (Sox9). NF-κB expression can modulate osteoblast differentiation by upregulating secreted protein acidic and rich in cysteine (SPARC) and interacting with mTOR signalling, bone morphogenetic protein (BMP) signalling or integrin-mediated signalling under stretch stimulation in the final osteogenic stage. In FOP, mutated ACVR1-induced NF-κB signalling exacerbates inflammation in macrophages and can promote chondrogenesis and osteogenesis in mesenchymal stem cells (MSCs) through interactions with smad signalling and mTOR signalling. This review summarizes the molecular mechanism of NF-κB signalling during HO and highlights potential therapeutics for treating HO.
Topics: Humans; NF-kappa B; Osteonectin; TOR Serine-Threonine Kinases; Inflammation; Ossification, Heterotopic
PubMed: 38439078
DOI: 10.1186/s12964-024-01533-w -
International Journal of Molecular... Nov 2023Metastasis leads to a high mortality rate in colorectal cancer (CRC). Increased neutrophil extracellular traps (NETs) formation is one of the main causes of metastasis....
Metastasis leads to a high mortality rate in colorectal cancer (CRC). Increased neutrophil extracellular traps (NETs) formation is one of the main causes of metastasis. However, the mechanism of NETs-mediated metastasis remains unclear and effective treatments are lacking. In this study, we found neutrophils from CRC patients have enhanced NETs formation capacity and increased NETs positively correlate with CRC progression. By quantitative proteomic analysis of clinical samples and cell lines, we found that decreased secreted protein acidic and rich in cysteine (SPARC) results in massive NETs formation and integrin α5β1 is the hub protein of NETs-tumor cell interaction. Mechanistically, SPARC regulates the activation of the nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) pathway by interacting with the receptor for activated C kinase 1 (RACK1). Over-activated NADPH oxidase generates more reactive oxygen species (ROS), leading to the release of NETs. Then, NETs upregulate the expression of integrin α5β1 in tumor cells, which enhances adhesion and activates the downstream signaling pathways to promote proliferation and migration. The combination of NADPH oxidase inhibitor diphenyleneiodonium chloride (DPI) and integrin α5β1 inhibitor ATN-161 (Ac-PHSCN-NH2) effectively suppresses tumor progression in vivo. Our work reveals the mechanistic link between NETs and tumor progression and suggests a combination therapy against NETs-mediated metastasis for CRC.
Topics: Humans; Extracellular Traps; NADPH Oxidases; Integrin alpha5beta1; Osteonectin; Proteomics; Neutrophils; Reactive Oxygen Species; Colorectal Neoplasms
PubMed: 37958984
DOI: 10.3390/ijms242116001 -
Journal of Functional Biomaterials Sep 2023New biocements based on a powdered mixture of calcium phosphate/monetite (TTCPM) modified with the addition of honey were prepared by mixing the powder and honey liquid...
New biocements based on a powdered mixture of calcium phosphate/monetite (TTCPM) modified with the addition of honey were prepared by mixing the powder and honey liquid components at a non-cytotoxic concentration of honey (up to 10% (/)). The setting process of the cements was not affected by the addition of honey, and the setting time of ~4 min corresponded to the fast setting calcium phosphate cements (CPCs). The cement powder mixture was completely transformed into calcium-deficient nanohydroxyapatite after 24 h of hardening in a simulated body fluid, and the columnar growth of long, needle-like nanohydroxyapatite particles around the original calcium phosphate particles was observed in the honey cements. The compressive strength of the honey cements was reduced with the content of honey in the cement. Comparable antibacterial activities were found for the cements with honey solutions on , but very low antibacterial activities were found for for all the cements. The enhanced antioxidant inhibitory activity of the composite extracts was verified. In vitro cytotoxicity testing verified the non-cytotoxic nature of the honey cement extracts, and the addition of honey promoted alkaline phosphatase activity, calcium deposit production, and the upregulation of osteogenic genes (osteopontin, osteocalcin, and osteonectin) by mesenchymal stem cells, demonstrating the positive synergistic effect of honey and CPCs on the bioactivity of cements that could be promising therapeutic candidates for the repair of bone defects.
PubMed: 37754871
DOI: 10.3390/jfb14090457 -
Biomolecules Jul 2023The SPARC gene plays multiple roles in extracellular matrix synthesis and cell shaping, associated with tumor cell migration, invasion, and metastasis. The SPARC gene is... (Review)
Review
The SPARC gene plays multiple roles in extracellular matrix synthesis and cell shaping, associated with tumor cell migration, invasion, and metastasis. The SPARC gene is also involved in the epithelial-mesenchymal transition (EMT) process, which is a critical phenomenon leading to a more aggressive cancer cell phenotype. SPARC gene overexpression has shown to be associated with poor survival in the mesothelioma (MESO) cohort from the TCGA database, indicating that this gene may be a powerful prognostic factor in MESO. Its overexpression is correlated with the immunosuppressive tumor microenvironment. Here, we summarize the omics advances of the SPARC gene, including the summary of SPARC gene expression associated with prognosis in pancancer and MESO, the immunosuppressive microenvironment, and cancer cell stemness. In addition, SPARC might be targeted by microRNAs. Notably, despite the controversial functions on angiogenesis, SPARC may directly or indirectly contribute to tumor angiogenesis in MESO. In conclusion, SPARC is involved in tumor invasion, metastasis, immunosuppression, cancer cell stemness, and tumor angiogenesis, eventually impacting patient survival. Strategies targeting this gene may provide novel therapeutic approaches to the treatment of MESO.
Topics: Humans; Cell Line, Tumor; Mesothelioma; MicroRNAs; Mesothelioma, Malignant; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Tumor Microenvironment; Osteonectin
PubMed: 37509139
DOI: 10.3390/biom13071103 -
Journal of Physiology and Biochemistry Nov 2023Binge drinking (BD) is an especially pro-oxidant model of alcohol consumption, mainly used by adolescents. It has recently been related to the hepatic IR-process....
Binge drinking (BD) is an especially pro-oxidant model of alcohol consumption, mainly used by adolescents. It has recently been related to the hepatic IR-process. Skeletal muscle is known to be involved in insulin action and modulation through myokine secretion. However, there is no information on muscle metabolism and myokine secretion after BD exposure in adolescents. Two experimental groups of adolescent rats have been used: control and BD-exposed one. Oxidative balance, energy status and lipid, and protein metabolism have been analyzed in muscle, together with myokine serum levels (IL-6, myostatin, LIF, IL-5, fractalkine, FGF21, irisin, BDNF, FSTL1, apelin, FABP3, osteocrin, osteonectin (SPARC), and oncostatin). In muscle, BD affects the antioxidant enzyme balance leading to lipid and protein oxidation. Besides, it also increases the activation of AMPK and thus contributes to decrease SREBP1 and pmTOR and to increase FOXO3a expressions, promoting lipid and protein degradation. These alterations deeply affect the myokine secretion pattern. This is the first study to examine a general myokine response after exposure to BD. BD not only caused a detrimental imbalance in myokines related to muscle turnover, decreased those contributing to increase IR-process, decreased FST-1 and apelin and their cardioprotective function but also reduced the neuroprotective BDNF. Consequently, BD leads to an important metabolic and energetic disequilibrium in skeletal muscle, which contributes to exacerbate a general IR-process.
Topics: Rats; Animals; Apelin; Brain-Derived Neurotrophic Factor; Binge Drinking; Muscle, Skeletal; Ethanol; Oxidative Stress; Lipids
PubMed: 37676577
DOI: 10.1007/s13105-023-00983-z