-
Journal of Translational Medicine Sep 2023Idiopathic pulmonary fibrosis (IPF) is fibrotic lung disease with no effective treatment. It is characterized by destruction of alveolar structure and pulmonary...
BACKGROUND
Idiopathic pulmonary fibrosis (IPF) is fibrotic lung disease with no effective treatment. It is characterized by destruction of alveolar structure and pulmonary interstitial fibrosis, leading to dyspnea and even asphyxia death of patients. Epithelial-mesenchymal transition (EMT) is considered to be a driving factor in the pathogenesis of IPF. Osteopontin (OPN) is a secreted protein widely present in the extracellular matrix and involved in the occurrence and development of a variety of diseases.
METHODS
The original datasets were obtained from NCBI GEO databases analyzed with the online tool GEO2R and EasyGEO. Bleomycin induced mouse pulmonary fibrosis model and OPN/OPN-biotin treated mouse model were established to investigate the role of OPN in mouse pulmonary fibrosis and the target cells of OPN. A549 cells and HBE cells were used to explore the mechanism of OPN-induced epithelial-mesenchymal transition (EMT) in epithelial cells and mass spectrometry was used to detect OPN downstream receptors. Precision-cut lung slices and lentivirus-treated mice with pulmonary fibrosis were used to examine the therapeutic effect of OPN and its downstream pathways on pulmonary fibrosis.
RESULTS
We demonstrate that the content of OPN in IPF bronchoalveolar lavage fluid (BALF) is high compared to the normal groups, and its expression level is correlated with prognosis. At the animal level, OPN was highly expressed at all stages of pulmonary fibrosis in mice, and the bronchoalveolar lavage fluid (BALF) could accurately reflect its expression in the lung. Next, we reveal that OPN was mainly expressed by macrophages and the main target cells of OPN were epithelial cells. Mice developed pulmonary fibrosis accompanied after treating the mice with OPN. Both in vitro and in vivo experiments confirmed that OPN could induce EMT of alveolar epithelial cells. Mechanistically, OPN binding triggered phosphorylation of FAK by CD44, thus activating snail1-mediated profibrotic protein synthesis. Inhibition of FAK phosphorylation and its downstream pathways can effectively alleviate pulmonary fibrosis in precision sections of lung tissue (PCLS) assay. OPN knockdown in bleomycin-induced lung fibrosis mice led to significantly less fibrosis.
CONCLUSION
Our data suggest that OPN mediates lung fibrosis through EMT, implicating its potential therapeutic target and prognostic indicator role for IPF. OPN may be a target for the diagnosis and treatment of IPF.
Topics: Animals; Humans; Mice; A549 Cells; Biological Assay; Bleomycin; Disease Models, Animal; Idiopathic Pulmonary Fibrosis; Osteopontin
PubMed: 37726818
DOI: 10.1186/s12967-023-04279-0 -
Hepatology (Baltimore, Md.) Feb 2024Primary sclerosing cholangitis (PSC) is an immune-mediated cholestatic liver disease for which pharmacological treatment options are currently unavailable. PSC is...
BACKGROUND AND AIMS
Primary sclerosing cholangitis (PSC) is an immune-mediated cholestatic liver disease for which pharmacological treatment options are currently unavailable. PSC is strongly associated with colitis and a disruption of the gut-liver axis, and macrophages are involved in the pathogenesis of PSC. However, how gut-liver interactions and specific macrophage populations contribute to PSC is incompletely understood.
APPROACH AND RESULTS
We investigated the impact of cholestasis and colitis on the hepatic and colonic microenvironment, and performed an in-depth characterization of hepatic macrophage dynamics and function in models of concomitant cholangitis and colitis. Cholestasis-induced fibrosis was characterized by depletion of resident KCs, and enrichment of monocytes and monocyte-derived macrophages (MoMFs) in the liver. These MoMFs highly express triggering-receptor-expressed-on-myeloid-cells-2 ( Trem2 ) and osteopontin ( Spp1 ), markers assigned to hepatic bile duct-associated macrophages, and were enriched around the portal triad, which was confirmed in human PSC. Colitis induced monocyte/macrophage infiltration in the gut and liver, and enhanced cholestasis-induced MoMF- Trem2 and Spp1 upregulation, yet did not exacerbate liver fibrosis. Bone marrow chimeras showed that knockout of Spp1 in infiltrated MoMFs exacerbates inflammation in vivo and in vitro , while monoclonal antibody-mediated neutralization of SPP1 conferred protection in experimental PSC. In human PSC patients, serum osteopontin levels are elevated compared to control, and significantly increased in advanced stage PSC and might serve as a prognostic biomarker for liver transplant-free survival.
CONCLUSIONS
Our data shed light on gut-liver axis perturbations and macrophage dynamics and function in PSC and highlight SPP1/OPN as a prognostic marker and future therapeutic target in PSC.
Topics: Humans; Cholangitis, Sclerosing; Osteopontin; Liver Cirrhosis; Bile Ducts; Cholestasis; Macrophages; Colitis
PubMed: 37535809
DOI: 10.1097/HEP.0000000000000557 -
Journal of Clinical Medicine Nov 2023The worldwide occurrence of diabetic kidney disease (DKD) is swiftly rising, primarily attributed to the growing population of individuals affected by type 2 diabetes.... (Review)
Review
The worldwide occurrence of diabetic kidney disease (DKD) is swiftly rising, primarily attributed to the growing population of individuals affected by type 2 diabetes. This surge has been transformed into a substantial global concern, placing additional strain on healthcare systems already grappling with significant demands. The pathogenesis of DKD is intricate, originating with hyperglycemia, which triggers various mechanisms and pathways: metabolic, hemodynamic, inflammatory, and fibrotic which ultimately lead to renal damage. Within each pathway, several mediators contribute to the development of renal structural and functional changes. Some of these mediators, such as inflammatory cytokines, reactive oxygen species, and transforming growth factor β are shared among the different pathways, leading to significant overlap and interaction between them. While current treatment options for DKD have shown advancement over previous strategies, their effectiveness remains somewhat constrained as patients still experience residual risk of disease progression. Therefore, a comprehensive grasp of the molecular mechanisms underlying the onset and progression of DKD is imperative for the continued creation of novel and groundbreaking therapies for this condition. In this review, we discuss the current achievements in fundamental research, with a particular emphasis on individual factors and recent developments in DKD treatment.
PubMed: 38068400
DOI: 10.3390/jcm12237349 -
Arteriosclerosis, Thrombosis, and... Nov 2023Perivascular adipose tissue (PVAT) is vital for vascular homeostasis, and PVAT dysfunction is associated with increased atherosclerotic plaque burden. But the mechanisms...
Single-Cell RNA Sequencing of Coronary Perivascular Adipose Tissue From End-Stage Heart Failure Patients Identifies Macrophage Subpopulation as a Target for Alleviating Fibrosis.
BACKGROUND
Perivascular adipose tissue (PVAT) is vital for vascular homeostasis, and PVAT dysfunction is associated with increased atherosclerotic plaque burden. But the mechanisms underlining coronary PVAT dysfunction in coronary atherosclerosis remain elusive.
METHODS
We performed single-cell RNA sequencing of the stromal vascular fraction of coronary PVAT from 3 groups of heart transplant recipients with end-stage heart failure, including 3 patients with nonobstructive coronary atherosclerosis, 3 patients with obstructive coronary artery atherosclerosis, and 4 nonatherosclerosis control subjects. Bioinformatics was used to annotate the cellular populations, depict the cellular developmental trajectories and interactions, and explore the differences among 3 groups of coronary PVAT at the cellular and molecular levels. Pathological staining, quantitative real-time polymerase chain reaction, and in vitro studies were performed to validate the key findings.
RESULTS
Ten cell types were identified among 67 936 cells from human coronary PVAT. Several cellular subpopulations, including (secreted phosphoprotein 1) macrophages and profibrotic fibroadipogenic progenitor cells, were accumulated in PVAT surrounding atherosclerotic coronary arteries compared with nonatherosclerosis coronary arteries. The fibrosis percentage was increased in PVAT surrounding atherosclerotic coronary arteries, and it was positively associated with the grade of coronary artery stenosis. Cellular interaction analysis suggested OPN (osteopontin) secreted by macrophages interacted with CD44 (cluster of differentiation 44)/integrin on fibroadipogenic progenitor cells. Strikingly, correlation analyses uncovered that higher level of SPP1 in PVAT correlates with a more severe fibrosis degree and a higher coronary stenosis grade. In vitro studies showed that conditioned medium from atherosclerotic coronary PVAT promoted the migration and proliferation of fibroadipogenic progenitor cells, while such effect was prevented by blocking CD44 or integrin.
CONCLUSIONS
macrophages accumulated in the PVAT surrounding atherosclerotic coronary arteries, and they promoted the migration and proliferation of fibroadipogenic progenitor cells via OPN-CD44/integrin interaction and thus aggravated the fibrosis of coronary PVAT, which was positively correlated to the coronary stenosis burden. Therefore, macrophages in coronary PVAT may participate in the progression of coronary atherosclerosis.
Topics: Humans; Coronary Artery Disease; Osteopontin; Adipose Tissue; Atherosclerosis; Coronary Stenosis; Macrophages; Fibrosis; Integrins; Sequence Analysis, RNA; Heart Failure
PubMed: 37706320
DOI: 10.1161/ATVBAHA.123.319828 -
Current Osteoporosis Reports Dec 2023Orthodontic tooth movement is characterized by periodontal tissue responses to mechanical loading, leading to clinically relevant functional adaptation of jaw bone.... (Review)
Review
PURPOSE OF REVIEW
Orthodontic tooth movement is characterized by periodontal tissue responses to mechanical loading, leading to clinically relevant functional adaptation of jaw bone. Since osteocytes are significant in mechanotransduction and orchestrate osteoclast and osteoblast activity, they likely play a central role in orthodontic tooth movement. In this review, we attempt to shed light on the impact and role of osteocyte mechanotransduction during orthodontic tooth movement.
RECENT FINDINGS
Mechanically loaded osteocytes produce signaling molecules, e.g., bone morphogenetic proteins, Wnts, prostaglandins, osteopontin, nitric oxide, sclerostin, and RANKL, which modulate the recruitment, differentiation, and activity of osteoblasts and osteoclasts. The major signaling pathways activated by mechanical loading in osteocytes are the wingless-related integration site (Wnt)/β-catenin and RANKL pathways, which are key regulators of bone metabolism. Moreover, osteocytes are capable of orchestrating bone adaptation during orthodontic tooth movement. A better understanding of the role of osteocyte mechanotransduction is crucial to advance orthodontic treatment. The optimal force level on the periodontal tissues for orthodontic tooth movement producing an adequate biological response, is debated. This review emphasizes that both mechanoresponses and inflammation are essential for achieving tooth movement clinically. To fully comprehend the role of osteocyte mechanotransduction in orthodontic tooth movement, more knowledge is needed of the biological pathways involved. This will contribute to optimization of orthodontic treatment and enhance patient outcomes.
Topics: Humans; Osteocytes; Mechanotransduction, Cellular; Tooth Movement Techniques; Osteoclasts; Osteoblasts; Bone Remodeling
PubMed: 37792246
DOI: 10.1007/s11914-023-00826-2 -
Journal of Personalized Medicine Aug 2023The biological functions of osteopontin (OPN) are diverse and specific to physiological and pathophysiological conditions implicated in inflammation, biomineralization,... (Review)
Review
The biological functions of osteopontin (OPN) are diverse and specific to physiological and pathophysiological conditions implicated in inflammation, biomineralization, cardiovascular diseases, cellular viability, cancer, diabetes, and renal stone disease. We aimed to present the role of OPN in respiratory health and disease. OPN influences the immune system and is a chemo-attractive protein correlated with respiratory disease severity. There is evidence that OPN can advance the disease stage associated with its fibrotic, inflammatory, and immune functions. OPN contributes to eosinophilic airway inflammation. OPN can destroy the lung parenchyma through its neutrophil influx and fibrotic mechanisms, linking OPN to at least one of the two major chronic obstructive pulmonary disease phenotypes. Respiratory diseases that involve irreversible lung scarring, such as idiopathic pulmonary disease, are linked to OPN, with protein levels being overexpressed in individuals with severe or advanced stages of the disorders and considerably lower levels in those with less severe symptoms. OPN plays a significant role in lung cancer progression and metastasis. It is also implicated in the pathogenesis of pulmonary hypertension, coronavirus disease 2019, and granuloma generation.
PubMed: 37623509
DOI: 10.3390/jpm13081259 -
Heliyon Oct 2023Osteopontin (OPN) is a multifunctional protein secreted intracellularly and extracellularly by various cell types, including NK cells, macrophages, osteoblasts, T cells,... (Review)
Review
Osteopontin (OPN) is a multifunctional protein secreted intracellularly and extracellularly by various cell types, including NK cells, macrophages, osteoblasts, T cells, and cancer cells. Owing to its diverse distribution, OPN plays a role in cell proliferation, stem-cell-like properties, epithelial-mesenchymal transformation, glycolysis, angiogenesis, fibrosis, invasion, and metastasis. In this review, we discuss recent findings, interpret representative studies on OPN expression in cancer, clarify that elevated OPN levels are observed in multiple cancer types (including colorectal, breast, lung, and liver cancer), and explore how OPN-macrophage interactions shape the tumor microenvironment. We also summarize progress in OPN research with regard to tumor therapy, which can facilitate the development of novel anti-tumor treatment strategies.
PubMed: 37867833
DOI: 10.1016/j.heliyon.2023.e21055 -
Cell Reports Sep 2023Chronic neurodegeneration and acute injuries lead to neuron losses via diverse processes. We compared retinal ganglion cell (RGC) responses between chronic glaucomatous...
Chronic neurodegeneration and acute injuries lead to neuron losses via diverse processes. We compared retinal ganglion cell (RGC) responses between chronic glaucomatous conditions and the acute injury model. Among major RGC subclasses, αRGCs and intrinsically photosensitive RGCs (ipRGCs) preferentially survive glaucomatous conditions, similar to findings in the retina subject to axotomy. Focusing on an αRGC intrinsic factor, Osteopontin (secreted phosphoprotein 1 [Spp1]), we found an ectopic neuronal expression of Osteopontin (Spp1) in other RGCs subject to glaucomatous conditions. This contrasted with the Spp1 downregulation subject to axotomy. αRGC-specific Spp1 elimination led to significant αRGC loss, diminishing their resiliency. Spp1 overexpression led to robust neuroprotection of susceptible RGC subclasses under glaucomatous conditions. In contrast, Spp1 overexpression did not significantly protect RGCs subject to axotomy. Additionally, SPP1 marked adult human RGC subsets with large somata and SPP1 expression in the aqueous humor correlated with glaucoma severity. Our study reveals Spp1's role in mediating neuronal resiliency in glaucoma.
Topics: Humans; Retinal Ganglion Cells; Osteopontin; Optic Nerve; Optic Nerve Diseases; Glaucoma
PubMed: 37624696
DOI: 10.1016/j.celrep.2023.113038 -
Advanced Science (Weinheim,... Aug 2023The knowledge of osteoarthritis (OA) has nowadays been extended from a focalized cartilage disorder to a multifactorial disease. Although recent investigations have...
The knowledge of osteoarthritis (OA) has nowadays been extended from a focalized cartilage disorder to a multifactorial disease. Although recent investigations have reported that infrapatellar fat pad (IPFP) can trigger inflammation in the knee joint, the mechanisms behind the role of IPFP on knee OA progression remain to be defined. Here, dysregulated osteopontin (OPN) and integrin β3 signaling are found in the OA specimens of both human and mice. It is further demonstrated that IPFP-derived OPN participates in OA progression, including activated matrix metallopeptidase 9 in chondrocyte hypertrophy and integrin β3 in IPFP fibrosis. Motivated by these findings, an injectable nanogel is fabricated to provide sustained release of siRNA Cd61 ( Nanogel/siRNA Cd61) that targets integrins. The Nanogel possesses excellent biocompatibility and desired targeting abilities both in vitro and in vivo. Local injection of Nanogel/siRNA Cd61 robustly alleviates the cartilage degeneration, suppresses the advancement of tidemark, and reduces the subchondral trabecular bone mass in OA mice. Taken together, this study provides an avenue for developing Nanogel/siRNA Cd61 therapy to mitigate OA progression via blocking OPN-integrin β3 signaling in IPFP.
Topics: Humans; Mice; Animals; Integrin beta3; Nanogels; Osteopontin; Cartilage, Articular; Knee Joint; Osteoarthritis, Knee; Adipose Tissue; RNA, Small Interfering; Oligopeptides
PubMed: 37218542
DOI: 10.1002/advs.202300897 -
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