Search Results (46)

Background: Intratumour heterogeneity (ITH) is one of the key characteristics of cancer and is closely associated with patient prognosis, treatment resistance, and tumor metastasis. Nevertheless, the study of ITH in hepatocellular carcinoma (HCC) remains limited. Methods: The present study elucidated the influence of ITH on the tumor microenvironment (TME) in HCC. We applied Non-negative Matrix Factorization (NMF) analysis to a cohort of 78 single-cell RNA sequencing (scRNA-seq) HCC samples to systematically characterize ITH. Furthermore, by integrating spatial transcriptomics (ST) data from five HCC patients, we comprehensively analyzed the spatial organization and functional properties of distinct niches within HCC. We conducted a detailed analysis of the cell-type co-localization relationships within the TME and constructed a comprehensive atlas of HCC spatial organization. Results: We observed a co-localization relationship between hypoxia tumor cells, plasmalemma vesicle-associated protein (PLVAP⁺) endothelial cells (EC), and vascular endothelial growth factor A (VEGFA⁺) cancer-associated fibroblasts (CAF), suggesting a key role for hypoxia tumor cells in VEGFA⁺ CAF transformation and tumor angiogenesis. We identified a unique boundary region enriched with dendritic cells1 (DC1), interferon-expressing tumor cells, lymphatic EC, C–X–C Motif Chemokine Ligand 10 (CXCL10⁺) macrophages (Mac), and secreted phosphoprotein 1 (SPP1⁺) Mac located between the tumor-infiltrating immune cells and tumor regions. Furthermore, we found that CXCL10⁺ Mac and SPP1⁺ Mac, despite co-localizing in the boundary region, exhibit distinct functions, which may be attributed to their unique spatial locations, with the former being closer to the immune-infiltrated region and the latter more proximal to the tumor area. Conclusions: Our study highlights the critical role of spatial interactions between tumor cells and the microenvironment in HCC. The findings offer new insights into ITH and underscore the importance of spatial organization in understanding cancer biology and designing future precision therapies. Full article

Although numerous experimental studies have demonstrated the carcinogenic potential of multi-walled carbon nanotubes (MWCNTs) in lungs, the underlying molecular mechanisms—especially gene expression changes associated with different tumor types—remain poorly characterized. To elucidate the molecular signatures associated with MWCNT-induced carcinogenesis, we performed microarray-based gene expression profiling of rat lung tumors induced by MWCNT-7, including both adenocarcinoma (ADC) and malignant mesothelioma (MM), as well as ADCs induced by two types of double-walled CNTs (DWCNTs) differing in fiber length (1.5 µm and 7 µm). Hierarchical clustering revealed that the MWCNT-7-induced MM exhibited a gene expression profile distinct from the ADCs. The ADCs induced by the DWCNTs and the ADC induced by MWCNT-7 shared several pathways that were distinct from those of the MWCNT-7 induced MM. The distinct pathways upregulated in the ADCs versus the MM support the conclusion that MWCNT-induced ADCs arise through distinct biological mechanisms compared to MWCNT-induced MMs and identified tumor-type-specific biomarker candidates: complement factor I (CFI) and secreted phosphoprotein 1 (SPP1) for ADCs, and fibronectin 1 (FN1) for MM. In addition, the gene expression profiles of the ADCs induced by the three fiber types indicate that both types of thin flexible DWCNTs used in the present study promoted a number of carcinogenic pathways in the rat lung that were also promoted by MWCNT-7, which is a class 2B carcinogen. These results support the conclusion that DWCNTs are carcinogenic in the rat lung and highlight the importance of further assessments of the potential lung carcinogenicity of inhaled thin flexible CNTs. Full article

Background/Objectives: Immune checkpoint blockade (ICB) has emerged as a promising therapeutic option for hepatocellular carcinoma (HCC), yet reliable biomarkers to predict clinical outcomes remain limited. Tumor-associated macrophages (TAMs) are increasingly recognized as key regulators of the tumor immune microenvironment. Methods: We interrogated a publicly available HCC single-cell RNA sequencing (scRNA-seq) dataset to characterize intratumoral immune cell subpopulations. Through unsupervised clustering and gene signature analysis, we identified a distinct subset of SPP1 (secreted phosphoprotein 1, also known as osteopontin) and BCL2A1 (Bcl-2-related protein A1) double-positive TAMs. Their abundance was quantified and associated with patient outcomes. Further independent HCC transcriptomic datasets with annotated PD1-based ICB response status were used for examination. Results: Across the discovery (GSE149614; n = 10) cohort, elevated expression of intratumoral SPP1⁺BCL2A1⁺ TAMs was identified in HCC. In the ICB datasets (GSE151530; n = 4), patients with high SPP1⁺BCL2A1⁺ TAM expression further exhibited significantly poorer responses to ICB therapy. Further, the validation cohort (GSE206325; n = 18) confirmed these findings accordingly. Notably, these TAMs were expressed thoroughly within the immunosuppressive T-cell microenvironment in non-responders but were distinctly expressed among the cytotoxic T-cell responses in responders. Conclusions: Our findings identify SPP1⁺BCL2A1⁺ TAMs as a poor prognostic biomarker in HCC patients undergoing ICB therapy. By promoting an immunosuppressive microenvironment, SPP1⁺BCL2A1⁺ TAMs, which are survival-advantaged, may represent both a predictive marker and a potential therapeutic target to enhance the efficacy of immunotherapy. Full article

This study investigated the interactive effects of dietary vitamin A (VA) and all-trans retinoic acid (ATRA) on growth performance and intestinal health in broilers. A total of 432 one-day-old male Arbor Acres chicks were assigned to a 2 × 3 factorial design with two VA levels (2000 and 6000 IU/kg) and three ATRA levels (0, 0.25, and 0.50 mg/kg). The maize–soybean meal basal diet contained 180 IU/kg VA without extra VA supplementation. Results showed that compared with 0 mg/kg ATRA, 0.50 mg/kg ATRA enhanced average daily gain (ADG) during days 1–21 (p < 0.05). Compared with 2000 IU/kg VA, 6000 IU/kg VA improved body weight on day 35 as well as ADG and feed intake during days 22–35 and reduced feed conversion ratio over the entire trial (p < 0.05). There were VA × ATRA interactions for the ratio of villus height (VH) to crypt depth (CD) in duodenum as well as VH and CD in ileum on day 21 (p < 0.05). The 0.25 mg/kg ATRA decreased duodenal VH/CD and ileal VH in broilers fed 2000 and 6000 IU/kg VA, respectively (p < 0.05). The 0.50 mg/kg ATRA increased ileal VH in broilers fed both 2000 and 6000 IU/kg VA (p < 0.05). When birds were fed 6000 IU/kg VA, 0.50 mg/kg ATRA increased ileal CD compared with 0.25 mg/kg CD (p < 0.05). On day 35, compared with 0 mg/kg ATRA, 0.25 mg/kg ATRA increased ileal VH while 0.50 mg/kg ATRA decreased ileal CD, and both of them increased ileal VH/CD (p < 0.05). The VA × ATRA interactions for mRNA expression of jejunal Mucin5ac on day 21 and jejunal Occludin, Claudin-1, Mucin 2, leucine-rich-repeat-containing G-protein-coupled receptor 5⁺ (Lgr5⁺), zinc and ring finger 3 (Znrf3), and secreted phosphoprotein 1 (SPP1) on day 35 were detected (p < 0.05). Dietary 0.50 mg/kg ATRA up-regulated jejunal Mucin5ac expression in broilers fed 6000 IU/kg VA on day 21 as well as Claudin-1, Znrf3, and SPP1 expression broilers fed 2000 IU/kg VA on day 35 (p < 0.05). The 0.25 mg/kg ATRA down-regulated Occludin expression in broilers fed 6000 IU/kg VA on day 35 (p < 0.05). The 0.25 mg/kg ATRA decreased and increased Lgr5⁺ expression on day 35 in broilers fed 2000 and 6000 IU/kg VA, respectively (p < 0.05). Both 0.25 and 0.50 mg/kg ATRA down-regulated Mucin-2 expression in broilers fed 2000 IU/kg VA on day 35 (p < 0.05). The VA × ATRA interactions were observed for jejunal retinol dehydrogenase 10 (RDH10), cytochrome P450, family 26, subfamily A, polypeptide 1 (CYP26A1), retinoic acid receptor (RAR) α, and RARβ expression on days 21 and 35 (p < 0.05). Both 0.25 and 0.50 mg/kg up-regulated RDH10, CYP26A1, and RARβ expression in broilers fed 6000 IU/kg VA (p < 0.05). The RARα expression was up-regulated by 0.50 and 0.25 mg/kg ATRA on days 21 and 35, respectively (p < 0.05). Plasma metabolomics identified 269 VA- and 185 ATRA-associated differential metabolites, primarily enriched in lipid metabolism, vitamin digestion and absorption, and bacterial infection pathways. In conclusion, dietary 0.50 mg/kg ATRA and 6000 IU/kg VA enhanced growth performance, intestinal integrity, and VA metabolism, partly through activation of retinoic acid receptors and modulation of plasma lipid metabolism. Full article

Nicotine-induced oxidative stress contributes significantly to vascular endothelial dysfunction. While negative air ions (NAIs) demonstrate potential blood-pressure-regulating and antioxidant properties, their mechanistic role remains unclear. This study examined the effects of NAIs against nicotine-induced oxidative damage and vascular endothelial injury in spontaneously hypertensive rats (SHRs). Western blotting was used to detect the expression levels of the α7nAChR/MAPK/AP1 pathway. Transcriptomic sequencing was performed to identify the differentially expressed genes after treatment with nicotine or NAIs. Furthermore, reactive oxygen species (ROS), endothelin-1 (ET-1), and [Ca²⁺]_i levels were detected in human aortic endothelial cells (HAECs) treated with nicotine, and the relationship between transcription factor activator protein 1 (AP1) and the target genes was further elucidated through ChIP–qPCR. Nicotine exposure in SHRs elevated blood pressure and induced oxidative damage through α7nAChR/MAPK/AP1 pathway activation, causing endothelial structural disruption. These effects manifested as decreased NO/eNOS and increased ET-1/ET_ab expression, while these changes were reversed by NAIs. In HAECs, nicotine impaired proliferation while increasing oxidative stress and [Ca²⁺]_i levels. This endothelial damage was markedly attenuated by either NAIs or fibronectin 1 (Fn1)/secreted phosphoprotein 1 (Spp1) knockdown. Mechanistically, we identified AP1 as the transcriptional regulator of FN1 and SPP1. NAIs attenuate nicotine-induced endothelial dysfunction in hypertension by inhibiting AP1-mediated FN1 and SPP1 activation, providing novel insights for smoking-associated cardiovascular risk. Full article

Secreted phosphoprotein 1 (SPP1), also known as osteopontin (OPN) or early T lymphocyte activation protein 1 (ETA-1), is a multifunctional protein involved in numerous biological processes, including immune modulation, stress response, and tissue remodeling. The role of SPP1 in interstitial lung diseases (ILDs) has become an area of increasing interest, given its elevated expression in various ILDs such as idiopathic pulmonary fibrosis (IPF), connective tissue disease-associated ILD (CTD-ILD), and pneumoconiosis, especially with recent data derived from single-cell RNA sequencing. In addition to ILDs, SPP1 has been implicated in infectious granulomatous lung diseases, lung and pleural malignancies, airway diseases, and COVID-19. In most cases, higher SPP1 levels in serum, bronchoalveolar lavage fluid, or lung tissue carry a poor prognosis. SPP1 is expressed in multiple cells critical for fibrogenesis, including macrophages, epithelial cells, and fibroblasts, and SPP1 has emerged as a potential target for therapeutic interventions. Here, we review the proposed mechanisms by which SPP1 contributes to the development of lung disease, with an emphasis on ILD. Full article

Rapid ascent to high altitudes by unacclimatized individuals significantly increases the risk of brain damage, given the brain’s heightened sensitivity to hypoxic conditions. Investigating hypoxia-tolerant animals can provide insights into adaptive mechanisms and guide prevention and treatment of hypoxic-ischemic brain injury. In this study, we exposed Brandt’s voles to simulated altitudes (100 m, 3000 m, 5000 m, and 7000 m) for 24 h and performed quantitative proteomic and phosphoproteomic analyses of brain tissue. A total of 3990 proteins and 9125 phosphorylation sites (phospho-sites) were quantified. Differentially expressed (DE) analysis revealed that while protein abundance changes were relatively modest, phosphorylation levels exhibited substantial alterations, suggesting that Brandt’s voles rapidly regulate protein structure and function through phosphorylation to maintain cellular homeostasis under acute hypoxia. Clustering analysis showed that most co-expressed proteins exhibited non-monotonic responses with increasing altitude, which were enriched in pathways related to cytokine secretion regulation and glutathione metabolism, contributing to reduced inflammation and oxidative stress. In contrast, most co-expressed phospho-sites showed monotonic changes, with phospho-proteins enriched in glycolysis and vascular smooth muscle contraction regulation. Kinase activity prediction identified nine hypoxia-responsive kinases, four of which belonging to the CAMK family. Immunoblot validated that the changes in CAMK2A activity were consistent with predictions, suggesting that CAMK may play a crucial role in hypoxic response. In conclusion, this work discovered that Brandt’s voles may cope with hypoxia through three key strategies: (1) vascular regulation to enhance cerebral blood flow, (2) glycolytic activation to increase energy production, and (3) activation of neuroprotective mechanisms. Full article

Inflammation appears to play a crucial role in the development and progression of penile cancer (PeCa). Two molecular pathways of PeCa are currently described: HPV-dependent and HPV-independent. The tumor immune microenvironment (TIME) of PeCa is characterized by the presence of tumor-associated macrophages, cancer-associated fibroblasts, and tumor-infiltrating lymphocytes. The components of the TIME produce pro-inflammatory cytokines and chemokines, which have been found to be overexpressed in PeCa tissues and are associated with tumor progression and unfavorable prognoses. Additionally, the nuclear factor kappa B (NF-κB) pathway and secreted phosphoprotein 1 (SPP1) have been implicated in PeCa pathogenesis. Elevated C-reactive protein (CRP) levels and the neutrophil-to-lymphocyte ratio (NLR) have been identified as potential prognostic biomarkers in PeCa. This overview presents the complex contribution of the inflammatory process and collates projects aimed at modulating TIME in PeCa. Full article

Cardiac fibrosis is a major driver of heart failure, a leading cause of morbidity and mortality worldwide. Advances in single-cell transcriptomics have revealed the pivotal role of SPP1+ macrophages in the pathogenesis of cardiac fibrosis, positioning them as critical mediators and promising therapeutic targets. SPP1+ macrophages, characterized by elevated expression of secreted phosphoprotein 1 (SPP1) and often co-expressing Triggering Receptor Expressed on Myeloid Cells 2 (TREM2), localize to fibrotic niches in the heart and other organs. These cells interact with activated fibroblasts and myofibroblasts, driving extracellular matrix remodeling and fibrosis progression. Their differentiation is orchestrated by signals such as CXCL4, GM-CSF, and IL-17A, further emphasizing their regulatory complexity. Therapeutic strategies targeting SPP1+ macrophages have shown encouraging preclinical results. Approaches include silencing Spp1 using antibody–siRNA conjugates and modulating key pathways involved in macrophage differentiation. These interventions have effectively reduced fibrosis and improved cardiac function in animal models. The mechanisms underlying SPP1+ macrophage function in cardiac fibrosis provide a foundation for innovative therapies aimed at mitigating pathological remodeling and improving outcomes in patients with heart failure. This emerging field has significant potential to transform the treatment of fibrotic heart disease. Full article

Anti-amyloid therapies (AATs) are increasingly being recognized as promising treatment options for Alzheimer’s disease (AD). Amyloid-related imaging abnormalities (ARIAs), small areas of edema and microbleeds in the brain presenting as abnormal signals in MRIs of the brain for patients with AD, are the most common side effects of AATs. While most ARIAs are asymptomatic, they can be associated with symptoms like nausea, headache, confusion, and gait instability and, less commonly, with more serious complications such as seizures and death. Cerebral amyloid angiopathy (CAA) has been found to be a major risk for ARIA development. The identification of sensitive and reliable non-invasive biomarkers for CAA has been an area of AD research over the years, but with the approval of AATs, this area has taken on a new urgency. This comprehensive review highlights several potential biomarkers, such as Aβ40, Aβ40/42, phosphorylated-tau217, neurofilament light chain, glial fibrillary acidic protein, secreted phosphoprotein 1, placental growth factor, triggering receptor expressed on myeloid cells 2, cluster of differentiation 163, proteomics, and microRNA. Identifying and staging CAA even before its consequences can be detected via neuroimaging are critical to allow clinicians to judiciously select appropriate candidates for AATs, stratify monitoring, properly manage therapeutic regimens for those experiencing symptomatic ARIAs, and optimize the treatment to achieve the best outcomes. Future studies can test potential plasma biomarkers in human beings and evaluate predictive values of individual markers for CAA severity. Full article

Background/Objectives: Cancer is caused by disruptions in the homeostatic state of normal cells, which results in dysregulation of the cell cycle, and uncontrolled growth and proliferation in affected cells to form tumors. Successful development of tumorous cells proceeds through the activation of pathways promoting cell development and functionality, as well as the suppression of immune signaling pathways; thereby providing these cells with proliferative advantages, which subsequently metastasize into surrounding tissues. These effects are primarily caused by the upregulation of oncogenes, of which SPP1 (secreted phosphoprotein 1), a non-collagenous bone matrix protein, is one of the most well-known. Methods: In this study, we conducted a further examination of the transcriptomic expression profile of SPP1 (Osteopontin) during the progression of cancer in four human tissues, breast, prostate, renal and skin, in order to understand the circumstances conducive to its activation and dysregulation, the biological pathways and other mechanisms involved as well as differences in its splicing patterns influencing its expression and functionality. Results: A significant overexpression of SPP1, as well as a set of other highly correlated genes, was seen in most of these tissues, indicating their extensive implication in cancer. Increased expression was observed with higher tumor stages, especially in renal and skin cancer, while applying therapeutic modalities targeting these genes dampened this effect in breast, prostate and skin cancer. Pathway analyses showed gene signatures related to cell growth and development enriched in tumorigenic conditions and earlier cancer stages, while later stages of cancer showed pathways associated with weakened immune response, in all cancers studied. Moreover, the utilization of therapeutic methods showed the activation of immunogenic pathways in breast, prostate and skin cancer, thereby confirming their viability. Further analyses of differential transcript expression levels in these oncogenes showed their exonic regions to be selectively overexpressed similarly in tumorigenic samples in all cancers studied, while also displaying significant differences in exon selectivity between constituent transcripts, providing a basis for their high degree of multifunctionality in cancer. Conclusions: Overall, this study corroborates the entrenched role of SPP1 in the progression of these four types of cancer, as confirmed by its overexpression and activation of related oncogenes, their co-involvement in key cellular pathways, and predisposition to exhibit differential splicing between their transcripts, while the above effects were found to be highly inhibitable through treatment methods, thereby highlighting its promising role in therapeutic development. Full article

Three-dimensional (3D) models with improved biomimicry are essential to reduce animal experimentation and drive innovation in tissue engineering. In this study, we investigate the use of alginate-based materials as polymeric inks for 3D bioprinting of osteogenic models using human bone marrow stem/stromal cells (hBMSCs). A composite bioink incorporating alginate, nano-hydroxyapatite (nHA), type I collagen (Col) and hBMSCs was developed and for extrusion-based printing. Rheological tests performed on crosslinked hydrogels confirm the formation of solid-like structures, consistently indicating a superior storage modulus in relation to the loss modulus. The swelling behavior analysis showed that the addition of Col and nHA into an alginate matrix can enhance the swelling rate of the resulting composite hydrogels, which maximizes cell proliferation within the structure. The LIVE/DEAD assay outcomes demonstrate that the inclusion of nHA and Col did not detrimentally affect the viability of hBMSCs over seven days post-printing. PrestoBlue^TM revealed a higher hBMSCs viability in the alginate-nHA-Col hydrogel compared to the remaining groups. Gene expression analysis revealed that alginate-nHA-col bioink favored a higher expression of osteogenic markers, including secreted phosphoprotein-1 (SPP1) and collagen type 1 alpha 2 chain (COL1A2) in hBMSCs after 14 days, indicating the pro-osteogenic differentiation potential of the hydrogel. This study demonstrates that the incorporation of nHA and Col into alginate enhances osteogenic potential and therefore provides a bioprinted model to systematically study osteogenesis and the early stages of tissue maturation in vitro. Full article

Background: Exposure to galactic cosmic radiation (GCR) is a breast cancer risk factor for female astronauts on deep-space missions. However, the specific signaling mechanisms driving GCR-induced breast cancer have not yet been determined. Methods: This study aimed to investigate the role of the estrogen-induced ERα-ERRα-SPP1 signaling axis in relation to mammary tumorigenesis in female Apc^Min/+ mice exposed to simulated GCR (GCRsim) at 100–110 days post-exposure. Results: In GCRsim-exposed mice, we observed marked elevations in serum estradiol, increased ductal overgrowth, ERα activation, and upregulation of ERα target genes with pro-tumorigenic functions in mammary tissues that was coupled with a higher mammary tumorigenesis, relative to control. Additionally, the ERα target gene Esrra, which encodes ERRα, was also upregulated along with its oncogenic target gene Spp1, indicating the activation of the ERα-ERRα-SPP1 axis in mouse mammary tissues after GCRsim exposure. Using a human tissue microarray and human breast cancer gene expression analysis, we also highlighted the conserved nature of the ERα-ERRα-SPP1 signaling in human breast cancer development. Conclusions: We identified the ERα-ERRα-SPP1 signaling axis as a potential key mediator in GCR-induced breast cancer with conserved activation in human breast cancer. These findings suggest that targeting this pathway could serve as a potential target for therapeutic intervention to safeguard female astronauts during and after a prolonged outer space mission. Full article

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease with limited effective therapies. Interstitial macrophages (IMs), especially those derived from monocytes, play an unknown role in IPF pathogenesis. By using single-cell RNA sequencing (scRNA-seq), bleomycin (BLM)-induced pulmonary fibrosis mouse lungs were analyzed to characterize the cellular landscape and heterogeneity of macrophages in this model. scRNA-seq was used to identify distinct interstitial macrophage subpopulations in fibrotic lungs, with monocyte-derived macrophages exhibiting a pro-fibrotic gene expression profile enriched in wound healing, extracellular matrix (ECM) remodeling, and pro-fibrotic cytokine production functions. A pseudotime analysis revealed that IMs originated from monocytes and differentiated along a specific trajectory. A cell–cell communication analysis demonstrated strong interactions between monocyte-derived interstitial macrophages (Mo-IMs) and fibroblasts through the transforming growth factor beta (TGFβ), secreted phosphoprotein 1 (SPP1), and platelet-derived growth factor (PDGF) signaling pathways. Flow cytometry validated the presence and expansion of Mo-IMs subpopulations in BLM-treated mice. This study reveals the cellular heterogeneity and developmental trajectory of lung macrophages in early BLM-induced pulmonary fibrosis, highlighting the crucial role of Mo-IMs with a pro-fibrotic phenotype in IPF pathogenesis via interactions with fibroblasts. Targeting these specific macrophage subpopulations and associated signaling pathways may provide novel therapeutic strategies for IPF. Full article

Hypertension has always posed a severe threat to people’s health. Food-derived angiotensin-converting enzyme (ACE)-inhibitory peptides have the potential to both prevent and treat hypertension. In the current investigation, two ACE-inhibitory peptides (SLPQ and PYVRYL) from goat milk were studied for their endothelial effects using EA.hy926 cells. PYVRYL outperformed SLPQ, yet neither impacted cell survival below 200 μg/mL. Investigation of SLPQ’s impact on EA.hy926 cell expression revealed 114 differentially expressed genes, with 65 downregulated and 49 upregulated. The genes were enriched in cytokine interactions, coagulation cascades, Hippo signaling, and ECM–receptor interaction. Decreased c-x-c motif chemokine ligand 2 (CXCL2), integrin subunit beta 2 (ITGB2), and fbj murine osteosarcoma viral oncogene homologue (FOS) expression and increased secreted phosphoprotein 1 (SPP1) expression may protect endothelial cells from inflammation. Our findings suggest that beyond ACE inhibition, SLPQ aids blood pressure control by influencing endothelial function, paving the way for its use as an antihypertensive food ingredient. Full article