Showing papers on "Osteopontin published in 2021"
TL;DR: In this article, conditions of urine supersaturation promote kidney damage by inducing the production of reactive oxygen species and oxidative stress, and that the ensuing inflammatory immune response promotes Randall's plaque initiation and calcium stone formation.
Abstract: Idiopathic calcium oxalate (CaOx) stones often develop attached to Randall's plaque present on kidney papillary surfaces. Similar to the plaques formed during vascular calcification, Randall's plaques consist of calcium phosphate crystals mixed with an organic matrix that is rich in proteins, such as inter-α-trypsin inhibitor, as well as lipids, and includes membrane-bound vesicles or exosomes, collagen fibres and other components of the extracellular matrix. Kidney tissue surrounding Randall's plaques is associated with the presence of classically activated, pro-inflammatory macrophages (also termed M1) and downregulation of alternatively activated, anti-inflammatory macrophages (also termed M2). In animal models, crystal deposition in the kidneys has been associated with the production of reactive oxygen species, inflammasome activation and increased expression of molecules implicated in the inflammatory cascade, including osteopontin, matrix Gla protein and fetuin A (also known as α2-HS-glycoprotein). Many of these molecules, including osteopontin and matrix Gla protein, are well known inhibitors of vascular calcification. We propose that conditions of urine supersaturation promote kidney damage by inducing the production of reactive oxygen species and oxidative stress, and that the ensuing inflammatory immune response promotes Randall's plaque initiation and calcium stone formation.
86 citations
TL;DR: In this article, the authors examined whether cancer-associated fibroblasts (CAFs) promote CSC features in pancreatic cancer (PC) cells and found that CAF-CAF enriched stemness in PC cells.
56 citations
TL;DR: In this paper, a 3D-printed scaffold for bone regeneration using silk-hydroxyapatite bone cements and osteoinductive, proangiogenic and neurotrophic growth factors or morphogens for accelerated bone formation is presented.
55 citations
TL;DR: Using nanobeam electron diffraction, it is shown that damage to structural integrity of collagen fibrils in Opn−/− bone tissue and their organization causes mineral disorganization, which could ultimately affect its mechanical integrity.
43 citations
TL;DR: In this article, a double-network hydrogel was used to rapidly reprogrammed differentiated cancer cells into cancer stem cells (CSCs) that display elevated tumorigenicity in vivo.
Abstract: Cancer recurrence can arise owing to rare circulating cancer stem cells (CSCs) that are resistant to chemotherapies and radiotherapies. Here, we show that a double-network hydrogel can rapidly reprogramme differentiated cancer cells into CSCs. Spheroids expressing elevated levels of the stemness genes Sox2, Oct3/4 and Nanog formed within 24 h of seeding the gel with cells from any of six human cancer cell lines or with brain cancer cells resected from patients with glioblastoma. Human brain cancer cells cultured on the double-network hydrogel and intracranially injected in immunodeficient mice led to higher tumorigenicity than brain cancer cells cultured on single-network gels. We also show that the double-network gel induced the phosphorylation of tyrosine kinases, that gel-induced CSCs from primary brain cancer cells were eradicated by an inhibitor of the platelet-derived growth factor receptor, and that calcium channel receptors and the protein osteopontin were essential for the regulation of gel-mediated induction of stemness in brain cancer cells. A double-network hydrogel can rapidly reprogramme differentiated tumour cells into cancer stem cells that display elevated tumorigenicity in vivo.
37 citations
TL;DR: In this article, osteopontin is found to be a key secreted factor that drives mesothelial-mediated ovarian cancer chemoresistance and stemness in vitro and in vivo.
Abstract: Ovarian cancer is the leading cause of gynecological malignancy-related deaths, due to its widespread intraperitoneal metastases and acquired chemoresistance. Mesothelial cells are an important cellular component of the ovarian cancer microenvironment that promote metastasis. However, their role in chemoresistance is unclear. Here, we investigated whether cancer-associated mesothelial cells promote ovarian cancer chemoresistance and stemness in vitro and in vivo. We found that osteopontin is a key secreted factor that drives mesothelial-mediated ovarian cancer chemoresistance and stemness. Osteopontin is a secreted glycoprotein that is clinically associated with poor prognosis and chemoresistance in ovarian cancer. Mechanistically, ovarian cancer cells induced osteopontin expression and secretion by mesothelial cells through TGF-β signaling. Osteopontin facilitated ovarian cancer cell chemoresistance via the activation of the CD44 receptor, PI3K/AKT signaling, and ABC drug efflux transporter activity. Importantly, therapeutic inhibition of osteopontin markedly improved the efficacy of cisplatin in both human and mouse ovarian tumor xenografts. Collectively, our results highlight mesothelial cells as a key driver of ovarian cancer chemoresistance and suggest that therapeutic targeting of osteopontin may be an effective strategy for enhancing platinum sensitivity in ovarian cancer.
37 citations
TL;DR: OPN and CXCL12 act as compelling targets to curb the tumor-promoting features of the stromal components and it is suggested that OPN-regulated CxCL12 network might act as potential therapeutic target for the management of CAF-mediated breast cancer progression.
Abstract: Tumor-stroma interactions are important determinants for the disease course in cancer. While stromal influence has been known to often play a tumor-promoting role, incomplete mechanistic insight into this phenomenon has prevented its therapeutic targeting. Stromal fibroblasts can be activated by tumor cells to differentiate into cancer-associated fibroblasts (CAFs), that exhibit the traits of myofibroblasts, and in turn, they increase cancer aggressiveness. Here, we report the crosstalk between the cancer cells and stromal fibroblasts that leads to tumor progression. The process is initiated by secretion of a chemokine like protein, osteopontin (OPN) from the cancer cells that differentiates the fibroblasts to myofibroblasts. Tumor-derived OPN achieves this transition by engaging CD44 and αvβ3 integrins on the fibroblast surface, which mediates signaling via Akt and ERK to induce Twist1-dependent gene expression. The OPN-driven CAFs then secrete CXCL12, which in turn triggers epithelial to mesenchymal transition (EMT) in the tumor cells. OPN, produced by the cancer cells, and CXCL12, secreted by activated fibroblasts, are necessary and sufficient to perpetuate the crosstalk. Knocking out OPN in carcinogen-induced mammary tumors or knocking down OPN in cancer cells and fibroblast co-implanted xenografts abrogates myofibroblast differentiation, Twist1, and CXCL12 expression. OPN expression is correlated with CAF-specific gene signature as shown by breast tumor tissue microarray consisting of 100 patient specimens. Bioinformatics analyses have confirmed that the expression of OPN is significantly correlated with the expression of myofibroblast-specific markers as demonstrated in human breast carcinoma dataset of 2509 patients. Our findings describe OPN and CXCL12 act as compelling targets to curb the tumor-promoting features of the stromal components and further suggested that OPN-regulated CXCL12 network might act as potential therapeutic target for the management of CAF-mediated breast cancer progression.
24 citations
TL;DR: Current knowledge on the Yin and Yang features of osteopontin in nervous system diseases is described, which would be relevant to develop highly specific tools targeting this multifunctional protein.
23 citations
TL;DR: In this article, an innovative hybrid scaffold composed of granular hydroxylapatite and collagen hemostat (Coll/HA) was used to evaluate human bone marrow-derived mesenchymal stem cells.
Abstract: Human bone marrow-derived mesenchymal stem cells (hBMSCs) and their derivative enhanced green fluorescent protein (eGFP)-hBMSCs were employed to evaluate an innovative hybrid scaffold composed of granular hydroxylapatite and collagen hemostat (Coll/HA). The cellular morphology/cytoskeleton organization and cell viability were investigated by immunohistochemistry (IHC) and AlamarBlue metabolic assay, respectively. The expression of osteopontin and osteocalcin proteins was analyzed by IHC and ELISA, whereas osteogenic genes were investigated by quantitative PCR (Q-PCR). Cell morphology of eGFP-hBMSCs was indistinguishable from that of parental hBMSCs. The cytoskeleton architecture of hBMSCs grown on the scaffold appeared to be well organized, whereas its integrity remained uninfluenced by the scaffold during the time course. Metabolic activity measured in hBMSCs grown on a biomaterial was increased during the experiments, up to day 21 (p < 0.05). The biomaterial induced the matrix mineralization in hBMSCs. The scaffold favored the expression of osteogenic proteins, such as osteocalcin and osteopontin. In hBMSC cultures, the scaffold induced up-regulation in specific genes that are involved in ossification process (BMP2/3, SPP1, SMAD3, and SP7), whereas they showed an up-regulation of MMP9 and MMP10, which play a central role during the skeletal development. hBMSCs were induced to chondrogenic differentiation through up-regulation of COL2A1 gene. Our experiments suggest that the innovative scaffold tested herein provides a good microenvironment for hBMSC adhesion, viability, and osteoinduction. hBMSCs are an excellent in vitro cellular model to assay scaffolds, which can be employed for bone repair and bone tissue engineering.
22 citations
TL;DR: In this paper, the authors investigated whether the inhibition of vascular calcification by bone marrow mesenchymal stem cell (BMSC)-derived exosomes is related to SIRT6 activity and assessed the regulatory relationship between HMGB1 and Sirtuin 6.
Abstract: Vascular calcification associated with chronic kidney disease (CKD) can increase the risk of mortality. Elevated serum levels of high mobility group box 1 (HMGB1) promotes vascular calcification in CKD via the Wnt/β-catenin pathway. Sirtuin 6 (SIRT6) prevents fibrosis in CKD by blocking the expression of β-catenin target genes through deacetylation. This study aimed to investigate whether the inhibition of vascular calcification by bone marrow mesenchymal stem cell (BMSC)-derived exosomes is related to SIRT6 activity and assess the regulatory relationship between HMGB1 and SIRT6. CKD characteristics, osteogenic markers, calcium deposition, and the differential expression of HMGB1 and SIRT6 have been measured in a 5/6 nephrectomized mouse CKD model fed a high-phosphate diet to induce aortic calcification. In vitro assays were also performed to validate the in vivo findings. High phosphate promotes the translocation of HMGB1 from the nucleus to the cytosol and induces the expression of Runx2, osteopontin, and Msx2. However, BMSC-derived exosomes were found to alleviate CKD-related fibrosis and the induction of osteogenic genes although less significantly when SIRT6 expression is suppressed. SIRT6 was found to modulate the cytosol translocation of HMGB1 by deacetylation in vascular smooth muscle cells. Our results indicate that BMSC-derived exosomes inhibit high phosphate-induced aortic calcification and ameliorate renal function via the SIRT6–HMGB1 deacetylation pathway.
20 citations
TL;DR: In this article, the authors investigated the mechanism of action of osteopontin (OPN) in human colorectal cancer and determined the efficacy of OPN blockade immunotherapy in suppression of colon cancer.
Abstract: Human colorectal cancers are mostly microsatellite-stable with no response to anti-PD-1 blockade immunotherapy, necessitating the development of a new immunotherapy. Osteopontin (OPN) is elevated in human colorectal cancer and may function as an immune checkpoint. We aimed at elucidating the mechanism of action of OPN and determining the efficacy of OPN blockade immunotherapy in suppression of colon cancer. We report here that OPN is primarily expressed in tumor cells, myeloid cells, and innate lymphoid cells in human colorectal carcinoma. Spp1 knock out mice exhibit a high incidence and fast growth rate of carcinogen-induced tumors. Knocking out Spp1 in colon tumor cells increased tumor-specific CTL cytotoxicity in vitro and resulted in decreased tumor growth in vivo. The OPN protein level is elevated in the peripheral blood of tumor-bearing mice. We developed four OPN neutralization monoclonal antibodies based on their efficacy in blocking OPN inhibition of T cell activation. OPN clones 100D3 and 103D6 increased the efficacy of tumor-specific CTLs in killing colon tumor cells in vitro and suppressed colon tumor growth in tumor-bearing mice in vivo. Our data indicate that OPN blockade immunotherapy with 100D3 and 103D6 has great potential to be further developed for colorectal cancer immunotherapy and for rendering a colorectal cancer response to anti-PD-1 immunotherapy.
TL;DR: In conclusion, circ-ITCH upregulated YAP1 expression to promote osteogenic differentiation in osteoporosis via sponging miR-214, which could act as a novel therapeutic target for osteopOrosis.
Abstract: Osteoporosis is the most prevailing primary bone disease and a growing health care burden. The aim of this study was to clarify the functional roles and mechanisms of the circ-ITCH regulating osteogenic differentiation of osteoporosis. Circ-ITCH and yes-associated protein 1 (YAP1) levels were downregulated, but the miR-214 level was upregulated in osteoporotic mice and patients. Knockdown of circ-ITCH inhibited the alkaline phosphatase (ALP) activity, mineralized nodule formation, and expression of runt-related transcription factor 2 (RUNX2), osteopontin (OPN), and osteocalcin (OCN) during osteogenic induction. Furthermore, miR-214 was a target of circ-ITCH, knockdown of miR-214 could impede the regulatory effects of sh-circ-ITCH on osteogenic differentiation. Moreover, miR-214 suppressed hBMSCs osteogenic differentiation by downregulating YAP1. Finally, in vivo experiments indicated that overexpression of circ-ITCH could improve osteogenesis in ovariectomized mice. In conclusion, circ-ITCH upregulated YAP1 expression to promote osteogenic differentiation in osteoporosis via sponging miR-214. Circ-ITCH could act as a novel therapeutic target for osteoporosis.
TL;DR: The present results prove the existence of a vasculature to bone tissue cross‐talk and the presence of VC lowers BMD, impairs bone metabolism, and affects several pathways in bone.
Abstract: An association between lower bone mineral density (BMD) and presence of vascular calcification (VC) has been reported in several studies. Chronic kidney disease (CKD) causes detrimental disturbances in the mineral balance, bone turnover, and development of severe VC. Our group has previously demonstrated expression of Wnt inhibitors in calcified arteries of CKD rats. Therefore, we hypothesized that the CKD-induced VC via this pathway signals to bone and induces bone loss. To address this novel hypothesis, we developed a new animal model using isogenic aorta transplantation (ATx). Severely calcified aortas from uremic rats were transplanted into healthy rats (uremic ATx). Transplantation of normal aortas into healthy rats (normal ATx) and age-matched rats (control) served as control groups. Trabecular tissue mineral density, as measured by μCT, was significantly lower in uremic ATx rats compared with both control groups. Uremic ATx rats showed a significant upregulation of the mineralization inhibitors osteopontin and progressive ankylosis protein homolog in bone. In addition, we found significant changes in bone mRNA levels of several genes related to extracellular matrix, bone turnover, and Wnt signaling in uremic ATx rats, with no difference between normal ATx and control. The bone histomorphometry analysis showed significant lower osteoid area in uremic ATx compared with normal ATx along with a trend toward fewer osteoblasts as well as more osteoclasts in the erosion lacunae. Uremic ATx and normal ATx had similar trabecular number and thickness. The bone formation rate did not differ between the three groups. Plasma biochemistry, including sclerostin, kidney, and mineral parameters, were similar between all three groups. ex vivo cultures of aorta from uremic rats showed high secretion of the Wnt inhibitor sclerostin. In conclusion, the presence of VC lowers BMD, impairs bone metabolism, and affects several pathways in bone. The present results prove the existence of a vasculature to bone tissue cross-talk. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
TL;DR: In this article, the authors investigated the effect of vitexin in the development of nephrolithiasis in mice, and showed that it has anti-inflammatory and anticancer effects.
TL;DR: In this article, the authors investigated whether autophagy was involved in the regulation of diabetic bone metabolism using Micro-CT, Elisa, histology, and histomorphometry analysis, and demonstrated that 1α,25-Dihydroxyvitamin D3 (1,25D) rescues glucose metabolism dysfunction and ameliorates bone loss.
TL;DR: In this article, the authors demonstrated the importance of cancer-associated macrophage-CAF interactions via osteopontin in hepatocellular carcinoma using RT-PCR.
Abstract: Background: Cancer-tumor associated macrophage (TAM)-cancer associated fibroblast (CAF) interactions are an important factor in the tumor microenvironment of hepatocellular carcinoma.
Materials and Methods: Hepatic stellate cells (HSCs) were cultured with cancer cell-conditioned medium (Ca.-CM), TAM-CM and CAF-CM, and the expression of CAF markers were evaluated by RT-PCR. Whether HSCs cultured with Ca.-CM, TAM-CM and CAF-CM contributed to the enhanced malignancy of cancer cells was examined using proliferation, invasion and migration assays. Furthermore, the differences between these three types of CM were evaluated using cytokine arrays.
Results: HSCs cultured with Ca.-CM, TAM-CM and CAF-CM showed significantly increased mRNA expression of αSMA, FAP and IL-6. All HSCs cultured with each CM exhibited significantly increased proliferation, invasion and migration of cancer cells. The osteopontin concentration was significantly higher in HSCs cultured with TAM-CM than the other CAF-CMs. Osteopontin inhibition significantly reduced osteopontin secretion from HSCs cultured with TAM-CM and suppressed the proliferation and invasion of cancer cells enhanced by HSCs cultured with TAM-CM.
Conclusions: We observed enhanced osteopontin secretion from TAMs, and this increased osteopontin further promoted osteopontin secretion from HSCs cultured with TAM-CM, leading to increased malignancy. For the first time, we demonstrated the importance of cancer-TAM-CAF interactions via osteopontin in hepatocellular carcinoma.
TL;DR: The study showed that CAG could alleviate the osteogenic differentiation inhibition induced by DEX in vitro and in vivo, and CAG might be considered as a candidate drug for the treatment of GIOP.
Abstract: Glucocorticoid-induced osteoporosis (GIOP) that is mainly featured as low bone density and increased risk of fracture is prone to occur with the administration of excessive glucocorticoids. Cycloastragenol (CAG) has been verified to be a small molecule that activates telomerase. Studied showed that up-regulated telomerase was associated with promoting osteogeneic differentiation, so we explored whether CAG could promote osteogenic differentiation to protect against GIOP and telomerase would be the target that CAG exerted its function. Our results demonstrated that CAG prominently increased the ALP activity, mineralization, mRNA of runt-related transcription factor 2, osteocalcin, osteopontin, collagen type I in both MC3T3-E1 cells and dexamethasone (DEX)-treated MC3T3-E1 cells. CAG up-regulated telomerase reverse transcriptase and the protective effect of CAG was blocked by telomerase inhibitor TMPyP4. Moreover, CAG improved bone mineralization in DEX-induced bone damage in a zebrafish larvea model. Therefore, the study showed that CAG could alleviate the osteogenic differentiation inhibition induced by DEX in vitro and in vivo, and CAG might be considered as a candidate drug for the treatment of GIOP.
TL;DR: HLE may protect against bone loss, and have potentials in the treatment of osteoporosis, according to in vivo and in vitro experiments.
Abstract: To systematically evaluate the protective effects of Humulus lupulus L. extract (HLE) on osteoporosis mice. In vivo experiment, a total of 35 12-week-old female ICR mice were equally divided into 5 groups: the sham control group (sham); the ovariectomy with vehicle group (OVX); the OVX with estradiol valerate [EV, 0.2 mg/(kg•d)] the OVX with low- or high-dose HLE groups [HLE, 1 g/(kg•d) and 3 g/(kg•d)], 7 in each group. Treatment began 1 week after the ovariectomized surgery and lasted for 12 weeks. Bone mass and trabecular bone mircoarchitecture were evaluated by micro computed tomography, and bone turnover markers in serum were evaluated using enzyme-linked immunosorbent assay (ELISA) kits. In vitro experiment, osteoblasts and osteoclasts were treated with HLE at doses of 0, 4, 20 and 100 µg/mL. Biomarkers for bone formation in osteoblasts and bone resorption in osteoclasts were analyzed. Compared with the OVX group, HLE exerted bone protective effects by the increase of estradiol (P<0.05), the improvement of cancellous bone structure, bone mineral density (P<0.01) and the reduction of serum alkaline phosphatase (ALP), tartrate resistant acid phosphatase (TRAP), bone gla-protein, c-terminal telopeptides of type I collagen (CTX-I) and deoxypyridinoline levels (P<0.01 for all). In vitro experiment, compared with the control group, HLE at 20 µg/mL promoted the cell proliferation (P<0.01), and increased the expression of bone morphogenetic protein-2 and osteopontin levels in osteoblasts (both P<0.05). HLE at 100 µg/mL increased the osteoblastic ALP activities, and HLE at all dose enhanced the extracellular matrix mineralization (both P<0.01). Furthermore, compared with the control group, HLE at 20 µg/mL and 100 µg/mL inhibited osteoclastic TRAP activity (P<0.01), and reduced the expression of matrix metalloproteinase-9 and cathepsin K (both P<0.05). HLE may protect against bone loss, and have potentials in the treatment of osteoporosis.
TL;DR: In this paper, the role of ADAMTSL2 in fibrosis using cultured human cardiac fibroblasts (CFBs) was investigated and it was shown that over-expression and treatment with extracellular ADADTSL 2 in human CFBs led to reduced TGFβ production and signalling.
Abstract: Fibrosis accompanies most heart diseases and is associated with adverse patient outcomes. Transforming growth factor (TGF)β drives extracellular matrix remodelling and fibrosis in the failing heart. Some members of the ADAMTSL (a disintegrin-like and metalloproteinase domain with thrombospondin type 1 motifs-like) family of secreted glycoproteins bind to matrix microfibrils, and although their function in the heart remains largely unknown, they are suggested to regulate TGFβ activity. The aims of this study were to determine ADAMTSL2 levels in failing hearts, and to elucidate the role of ADAMTSL2 in fibrosis using cultured human cardiac fibroblasts (CFBs). Cardiac ADAMTSL2 mRNA was robustly increased in human and experimental heart failure, and mainly expressed by fibroblasts. Over-expression and treatment with extracellular ADAMTSL2 in human CFBs led to reduced TGFβ production and signalling. Increased ADAMTSL2 attenuated myofibroblast differentiation, with reduced expression of the signature molecules α-smooth muscle actin and osteopontin. Finally, ADAMTSL2 mitigated the pro-fibrotic CFB phenotypes, proliferation, migration and contractility. In conclusion, the extracellular matrix-localized glycoprotein ADAMTSL2 was upregulated in fibrotic and failing hearts of patients and mice. We identified ADAMTSL2 as a negative regulator of TGFβ in human cardiac fibroblasts, inhibiting myofibroblast differentiation and pro-fibrotic properties.
TL;DR: It is found that the angiogenic potential of ADAM8 in GBM cells and in primary macrophages is mediated by the regulation of osteopontin (OPN), an important inducer of tumor angiogenesis.
Abstract: Glioblastoma multiforme (GBM) is the most aggressive type of brain cancer with a median survival of only 15 months. To complement standard treatments including surgery, radiation and chemotherapy, it is essential to understand the contribution of the GBM tumor microenvironment. Brain macrophages and microglia particularly contribute to tumor angiogenesis, a major hallmark of GBM. ADAM8, a metalloprotease-disintegrin strongly expressed in tumor cells and associated immune cells of GBMs, is related to angiogenesis and correlates with poor clinical prognosis. However, the specific contribution of ADAM8 to GBM tumorigenesis remains elusive. Knockdown of ADAM8 in U87 glioma cells led to significantly decreased angiogenesis and tumor volumes of these cells after stereotactic injection into striate body of mice. We found that the angiogenic potential of ADAM8 in GBM cells and in primary macrophages is mediated by the regulation of osteopontin (OPN), an important inducer of tumor angiogenesis. By in vitro cell signaling analyses, we demonstrate that ADAM8 regulates OPN via JAK/STAT3 pathway in U87 cells and in primary macrophages. As ADAM8 is a dispensable protease for physiological homeostasis, we conclude that ADAM8 could be a tractable target to modulate angiogenesis in GBM with minor side-effects.
TL;DR: In this article, Trelagliptin was shown to have a beneficial effect in osteoblastic differentiation and increased the activity of alkaline phosphatase (ALP), osteocalcin (OCN), osteopontin (OPN), and bone morphogenetic protein-2 (BMP-2).
Abstract: Osteoporosis, an aging-associated bone metabolic disease, is affecting millions of people worldwide. The deregulated process of osteoblastic differentiation has been linked with the progression of osteoporosis. Trelagliptin is a long-acting inhibitor of DPP-4 used for the management of type 2 diabetes mellitus. However, it is unknown whether Trelagliptin possesses a beneficial effect in osteoblastic differentiation. Interestingly, we found that treatment with Trelagliptin enhanced differentiation and promoted the mineralization of MC3T3-E1 cells. Firstly, Trelagliptin increased the activity of alkaline phosphatase (ALP) and promoted osteoblastic calcium deposition. Additionally, treatment with Trelagliptin upregulated ALP, osteocalcin (OCN), osteopontin (OPN), and bone morphogenetic protein-2 (BMP-2). Notably, Trelagliptin increased RUNX2, a major regulator of osteoblastic differentiation. Mechanistically, Trelagliptin upregulated the levels of p-AMPKα. Blockage of AMPK with compound C abolished the effects of Trelagliptin in RUNX2 and osteoblastic differentiation, suggesting the involvement of AMPK. Our findings suggest that Trelagliptin might possess a potential for the treatment of osteoporosis.
TL;DR: In this paper, it was shown that osteopontin (OPN) is a kinase that generates the majority of secreted phosphoproteins and regulates biomineralization, and its potential roles in bone resorption and breast cancer bone metastasis are unknown.
Abstract: Fam20C is a kinase that generates the majority of secreted phosphoproteins and regulates biomineralization. However, its potential roles in bone resorption and breast cancer bone metastasis are unknown. Here we show that Fam20C in the myeloid lineage suppresses osteoclastogenesis and bone resorption, during which osteopontin (OPN) is the most abundant phosphoprotein secreted in a Fam20C-dependent manner. OPN phosphorylation by Fam20C decreased OPN secretion, and OPN neutralization reduced Fam20C-deficiency-induced osteoclast differentiation and bone metastasis. In contrast, Fam20C in breast cancer cells promoted bone metastasis by facilitating the phosphorylation and secretion of BMP4, which in turn enhanced osteoclastogenesis. Mutation of the BMP4 phosphorylation site elevated BMP4 lysosomal degradation and reduced BMP4 secretion. In breast cancer cells, BMP4 depletion or treatment with a BMP4 signaling inhibitor diminished osteoclast differentiation and bone metastasis and abolished Fam20C-mediated regulation of these processes. Collectively, this study discovers distinct roles for Fam20C in myeloid cells and breast cancer cells and highlights OPN and BMP4 as potential therapeutic targets for breast cancer bone metastasis.
TL;DR: In this article, the authors examined the effect of cold atmospheric plasma (CAP) on the mineralization and cell proliferation of murine dental cementoblasts, and showed that CAP appears to have stimulatory effects on regeneration-associated cell functions in cementblasts.
Abstract: The aim of the study was to examine the efficacy of cold atmospheric plasma (CAP) on the mineralization and cell proliferation of murine dental cementoblasts. Cells were treated with CAP and enamel matrix derivates (EMD). Gene expression of alkaline phosphatase (ALP), bone gamma-carboxyglutamate protein (BGLAP), periostin (POSTN), osteopontin (OPN), osterix (OSX), collagen type I alpha 1 chain (COL1A1), dentin matrix acidic phosphoprotein (DMP)1, RUNX family transcription factor (RUNX)2, and marker of proliferation Ki-67 (KI67) was quantified by real-time PCR. Protein expression was analyzed by immunocytochemistry and ELISA. ALP activity was determined by ALP assay. Von Kossa and alizarin red staining were used to display mineralization. Cell viability was analyzed by XTT assay, and morphological characterization was performed by DAPI/phalloidin staining. Cell migration was quantified with an established scratch assay. CAP and EMD upregulated both mRNA and protein synthesis of ALP, POSTN, and OPN. Additionally, DMP1 and COL1A1 were upregulated at both gene and protein levels. In addition to upregulated RUNX2 mRNA levels, treated cells mineralized more intensively. Moreover, CAP treatment resulted in an upregulation of KI67, higher cell viability, and improved cell migration. Our study shows that CAP appears to have stimulatory effects on regeneration-associated cell functions in cementoblasts.
TL;DR: In this article, the authors demonstrate that severe hypoxia (1% O2) upregulates CD44 expression via activation of Hypoxia-Inducible Factor (HIF-1α), inducing GSCs to assume a highly invasive tumor.
TL;DR: In this paper, a slow-release system for microstructured titanium (Micro-Ti) was designed to promote osteogenesis and inhibit osteoclastogenesis by inserting naringin (NA), chitosan (CHI), and gelatin (GEL) multilayers through layer by layer technique.
Abstract: Osteoporosis is the most common cause of fractures in middle-aged and elderly people. Fracture repair can be difficult due to the decreased bone volume in osteoporosis patients and implants are often required. In this study, a slow-release system for microstructured titanium (Micro-Ti) was designed to promote osteogenesis and inhibit osteoclastogenesis. Firstly, Micro-Ti was prepared on titanium surfaces by dual acid etching. Micro-Ti was covered with naringin (NA), chitosan (CHI) and gelatin (GEL) multilayers through layer by layer technique, which is denoted as LBL (NA) coated-Ti. Osteoblasts (ME3T3-E1) and macrophages (RAW 264.7) were cultured on untreated and treated titanium surfaces in vitro. Osteoblasts grown on LBL (NA) coated-Ti showed higher alkaline phosphatase (ALP) and mineralization, consistent with qRT-PCR analysis of osteoblast genes including runt-related transcription factor 2 (Runx2), ALP, collagen I (Col I), osteocalcin (OCN), osteopontin (OPN), and osteoprotegerin (OPG). In contrast, acid tartarate-resistant phosphatase activity and the expression of osteoclastic differentiation related genes comprising of cathepsin K (CTSK), nuclear factor of activated T cells (NFAT), tartrate resistant acid phosphatase (TRAP) and V-ATPase (VATP) in osteoclasts were significantly reduced on LBL (NA) coated-Ti surfaces compared with other groups. These results indicate that microstructured titanium functionalized by naringin inserted multilayers enhanced the differentiation of osteoblasts and inhibited osteoclast formation. The proposed approach in this research provides a novel way to modify titanium-based implants for fracture repair in osteoporosis patients.
TL;DR: Psoralen, one of the active ingredients in Psoralea corylifolia, has been previously reported to regulate the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) as discussed by the authors.
Abstract: Psoralen, one of the active ingredients in Psoralea corylifolia, has been previously reported to regulate the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). A previous study revealed that psoralen can regulate the expression levels of microRNA-488 and runt-related transcription factor 2 (Runx2) to promote the osteogenic differentiation of BMSCs. However, the underlying signalling pathway in this process remains to be fully elucidated. BMSCs have also been confirmed to play a key role in the occurrence and development of osteoporosis, and are expected to be potential seed cells in the treatment of osteoporosis. In order to explore the potential signalling pathways of psoralen acting on BMSCs, in the present study, human BMSCs (hBMSCs) were treated with different concentrations of psoralen (0.1, 1, 10 and 100 µmol/l) and the TGF-β receptor I (RI) inhibitor SB431542 (5 µmol/l) in vitro for 3, 7 or 14 days. Cell Counting Kit-8 and MTT assays were used to measure cell proliferation and cell viability of hBMSCs following psoralen administration. Alkaline phosphatase (ALP) activity and alizarin red S staining were used to assess the osteogenic differentiation ability of hBMSCs. Reverse transcription-quantitative PCR and western blotting were used to measure the expression of osteogenic differentiation-related genes [bone morphogenetic protein 4 (BMP4), osteopontin (OPN), Runx2 and Osterix] and proteins associated with the TGF-β/Smad3 pathway [TGF-β1, TGF-β RI, phosphorylated (p-)Smad and Smad3]. Psoralen was found to increase the proliferation and viability of hBMSCs. Although different concentrations of psoralen enhanced ALP activity and the calcified nodule content in hBMSCs, the enhancement effects were more potent at lower concentrations (0.1, 1 and 10 µmol/l). The expression of BMP4, OPN, Osterix, Runx2, TGF-β1, TGF-β RI and p-Smad3 was also promoted by psoralen at lower concentrations (0.1, 1 and 10 µmol/l). In addition, whilst SB431542 could inhibit calcium deposition and osteogenic differentiation-related gene expression in hBMSCs, psoralen effectively reversed the inhibitory effects of SB431542. In conclusion, psoralen accelerates the osteogenic differentiation of hBMSCs by activating the TGF-β/Smad3 pathway, which may be valuable for the future clinical treatment of osteoporosis.
TL;DR: In this article, the role and mechanism of circRNA lipase maturation factor 1 (circLMF1) in Human aortic VSMCs (HASMCs) were explored.
Abstract: Atherosclerosis is a major cause of cardiovascular disease, in which vascular smooth muscle cells (VSMCs) proliferation and migration play a vital role. Circular RNAs (circRNAs) have been reported to be correlated with the VSMCs function. Therefore, this study is designed to explore the role and mechanism of circRNA lipase maturation factor 1 (circLMF1) in Human aortic VSMCs (HASMCs). The microarray was used for detecting the expression of circLMF1 in proliferative and quiescent HASMCs. Levels of circLMF1, microRNA-125a-3p (miR-125a-3p), vascular endothelial growth factor A (VEGFA), and fibroblast growth factor 1 (FGF1) were determined by real-time quantitative polymerase chain reaction (RT-qPCR). Cell viability, cell cycle progression, and migration were assessed by Cell Counting Kit-8 (CCK-8), flow cytometry, wound healing, and transwell assays, respectively. Western blot assay determined proliferating cell nuclear antigen (PCNA), Cyclin D1, matrix metalloproteinase (MMP2), osteopontin (OPN), VEGFA, and FGF1 protein levels. The possible interactions between miR-125a-3p and circLMF1, and miR-125a-3p and VEGFA or FGF1 were predicted by circbank or targetscan, and then verified by a dual-luciferase reporter, RNA Immunoprecipitation (RIP), RNA pull-down assays. CircLMF1, VEGFA, and FGF1 were increased, and miR-125a-3p was decreased in platelet-derived growth factor-BB (PDGF-BB)-inducted HASMCs. Functionally, circLMF1 knockdown hindered cell viability, cell cycle progression, and migration in PDGF-BB-treated HASMCs. Mechanically, circLMF1 could regulate VEGFA or FGF1 expression through sponging miR-125a-3p. Our findings revealed that circLMF1 deficiency could inhibit cell viability, cell cycle progression, and migration of PDGF-BB stimulated atherosclerosis model partly through the miR-125a-3p/VEGFA or FGF1 axis, suggesting that targeting circLMF1 can be a feasible therapeutic strategy for atherosclerosis.
TL;DR: In this paper, small interfering RNA (siRNA) was used to knock down Osteopontin (OPN) in a bleomycin (BLM)-induced pulmonary fibrosis (PF) mouse model to determine whether OPN siRNA is an effective therapeutic strategy for IPF.
TL;DR: In this article, a co-culture model of intrahepatic cholangiocarcinoma (ICC) cells and hepatic stellate cells (HSCs) was used to identify that HSCs triggered the expression of nuclear receptor family 4 subgroup A member 2 (NR4A2), a transcription factor previously reported as a molecular switch between inflammation and cancer, in ICC cells.
Abstract: Intrahepatic cholangiocarcinoma (ICC) is a highly fatal malignancy characterized by a vast amount of intra-tumoral fibroblasts. These fibroblasts are potentially implicated in maintaining the high aggressiveness of ICC, whereas its pro-cancer mechanisms remain scarcely reported. Here, by establishing co-culture models of ICC cells and hepatic stellate cells (HSCs), we identified that HSCs triggered the expression of nuclear receptor family 4 subgroup A member 2 (NR4A2), a transcription factor previously reported as a molecular switch between inflammation and cancer, in ICC cells. Functionally, NR4A2 promotes tumor proliferation, metastatic potentiality and represents an independent prognostic indicator for overall survival in ICC patients. Mechanistically, NR4A2 upregulates osteopontin (OPN) expression through transcriptional activation and thereby augments the activity of Wnt/β-catenin signaling. Intriguingly, in the context of co-culture, vascular endothelial growth factor (VEGF), a previously proved NR4A2 stimulus, not only enhances NR4A2 expression, but also can be blunted by the interference of the NR4A2-OPN axis. Altogether, this study suggests the NR4A2/OPN/Wnt signaling axis to be a pivotal executor of HSC-instigated cancer-promoting roles in ICC, and the NR4A2/OPN/VEGF positive feedback loop may help to reinforce the effect.
TL;DR: In this article, the authors found that the undefined OPN levels (mixture of FL-OPN and cleaved OPN) were elevated in plasma and reflected the pathology of TB and COVID-19 rather than FLOPN.
Abstract: Circulating full-length osteopontin (FL-OPN) is elevated in plasma from patients with various infectious diseases, such as adult T-cell leukemia, Mycobacterium tuberculosis (TB), hepatitis virus infection, leptospirosis, acquired immune deficiency syndrome (AIDS), AIDS/TB, and coronavirus disease 2019 (COVID-19). Proteolysis of OPN by thrombin, matrix metalloproteases, caspase 8/3, cathepsin D, plasmin, and enterokinase generates various cleaved OPNs with a variety of bioactivities by binding to different target cells. Moreover, OPN is susceptible to gradual proteolysis. During inflammation, one of the cleaved fragments, N-terminal thrombin-cleaved OPN (trOPN or OPN-Arg168 [OPN-R]), induces dendritic cell (DC) adhesion. Further cleavage by carboxypeptidase B2 or carboxypeptidase N removes Arg168 from OPN-R to OPN-Leu167 (OPN-L). Consequently, OPN-L decreases DC adhesion. In particular, the differences in plasma level over time are observed between FL-OPN and its cleaved OPNs during inflammation. We found that the undefined OPN levels (mixture of FL-OPN and cleaved OPN) were elevated in plasma and reflected the pathology of TB and COVID-19 rather than FL-OPN. These infections are associated with elevated levels of various proteases. Inhibition of the cleavage or the activities of cleaved products may improve the outcome of the therapy. Research on the metabolism of OPN is expected to create new therapies against infectious diseases.