Search Results (727)

Physiological levels of reactive oxygen species (ROS) play a crucial role as intracellular signaling molecules, helping to maintain cellular homeostasis. However, when ROS accumulate excessively, they become toxic to cells, leading to damage to lipids, proteins, and DNA. This oxidative stress can impair cellular function and lead to various forms of cell death, including apoptosis, necroptosis, ferroptosis, pyroptosis, paraptosis, parthanatos, and oxeiptosis. Despite their significance, the role of ROS in autosis (an autophagy-dependent form of cell death) remains largely unexplored. In this review, we gather current knowledge on autotic cell death and summarize how oxidative stress influences the activity of Beclin-1 and the Na⁺,K⁺-ATPase pump, both of which are critical effectors of this pathway. Finally, we discuss the theoretical potential for ROS to modulate this type of cell death, proposing a possible dual role for these species in autosis regulation through effectors such as HIF-1α, TFEB, or the FOXO family, and highlighting the need to experimentally address cellular redox status when working on autotic cell death. Full article

Background: Acute mountain sickness (AMS) is a prevalent and potentially life-threatening condition caused by rapid exposure to high-altitude hypoxia, affecting pulmonary and neurological functions. Tongqiao Jiuxin Oil (TQ), a traditional Chinese medicine formula composed of aromatic and resinous ingredients such as sandalwood, agarwood, frankincense, borneol, and musk, has been widely used in the treatment of cardiovascular and cerebrovascular disorders. Clinical observations suggest its potential efficacy against AMS, yet its pharmacological mechanisms remain poorly understood. Methods: The chemical profile of TQ was characterized using UHPLC-Q-Exactive Orbitrap HRMS. Network pharmacology was applied to predict the potential targets and pathways involved in AMS. A rat model of AMS was established by exposing animals to hypobaric hypoxia (~10% oxygen), simulating an altitude of approximately 5500 m. TQ was administered at varying doses. Physiological indices, oxidative stress markers (MDA, SOD, GSH), histopathological changes, and the expression of hypoxia- and apoptosis-related proteins (HIF-1α, VEGFA, EPO, Bax, Bcl-2, Caspase-3) in lung and brain tissues were assessed. Results: A total of 774 chemical constituents were identified from TQ. Network pharmacology predicted the involvement of multiple targets and pathways. TQ significantly improved arterial oxygenation and reduced histopathological damage in both lung and brain tissues. It enhanced antioxidant activity by elevating SOD and GSH levels and reducing MDA content. Mechanistically, TQ downregulated the expression of HIF-1α, VEGFA, EPO, and pro-apoptotic markers (Bax/Bcl-2 ratio, Caspase-3), while upregulated Bcl-2, the anti-apoptotic protein expression. Conclusions: TQ exerts protective effects against AMS-induced tissue injury by improving oxygen homeostasis, alleviating oxidative stress, and modulating hypoxia-related and apoptotic signaling pathways. This study provides pharmacological evidence supporting the potential of TQ as a promising candidate for AMS intervention, as well as the modern research method for multi-component traditional Chinese medicine. Full article

Background: Ulcerative colitis (UC), characterized by chronic intestinal inflammation, epithelial barrier dysfunction, and immune imbalance demands novel ameliorative strategies beyond conventional approaches. Methods: In this study, the probiotic properties of Lactobacillus paracaseiL21 (L. paracaseiL21) and its ability to ameliorate colitis were evaluated using an in vitro lipopolysaccharide (LPS)-induced intestinal crypt epithelial cell (IEC-6) model and an in vivo dextran sulfate sodium (DSS)-induced UC mouse model. Results: In vitro, L. paracaseiL21 decreased levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-8) while increasing anti-inflammatory IL-10 levels (p < 0.05) in LPS-induced IEC-6 cells, significantly enhancing the expression of tight junction proteins (ZO-1, occludin, claudin-1), thereby restoring the intestinal barrier. In vivo, both viable L. paracaseiL21 and its heat-inactivated postbiotic (H-L21) mitigated weight loss, colon shortening, and disease activity indices, concurrently reducing serum LPS and proinflammatory mediators. Interventions inhibited NF-κB signaling while activating HIF1α/AhR pathways, increasing IL-22 and mucin MUC2 to restore goblet cell populations. Gut microbiota analysis showed that both interventions increased the abundance of beneficial gut bacteria (Lactobacillus, Dubococcus, and Akkermansia) and improved faecal propanoic acid and butyric acid levels. H-L21 uniquely exerted an anti-inflammatory effect, marked by the regulation of Dubosiella, while L. paracaseiL21 marked by the Akkermansia. Conclusions: These results highlight the potential of L. paracaseiL21 as a candidate for the development of both probiotic and postbiotic formulations. It is expected to provide a theoretical basis for the management of UC and to drive the development of the next generation of UC therapies. Full article

Bone is the most frequent site of distant metastasis in advanced prostate cancer (PCa), contributing substantially to patient morbidity and mortality. Hypoxia, a defining feature of the solid tumour microenvironment, plays a pivotal role in driving bone-tropic progression by promoting epithelial-to-mesenchymal transition (EMT), cancer stemness, extracellular matrix (ECM) remodelling, and activation of key signalling pathways such as Wingless/Integrated (Wnt) Wnt/β-catenin and PI3K/Akt. Hypoxia also enhances the secretion of extracellular vesicles (EVs), enriched with pro-metastatic cargos, and upregulates bone-homing molecules including CXCR4, integrins, and PIM kinases, fostering pre-metastatic niche formation and skeletal colonisation. In this review, we analysed current evidence on how hypoxia orchestrates PCa dissemination to bone, focusing on the molecular crosstalk between HIF signalling, Wnt activation, EV-mediated communication, and cellular plasticity. We further explore therapeutic strategies targeting hypoxia-related pathways, such as HIF inhibitors, hypoxia-activated prodrugs, and Wnt antagonists, with an emphasis on overcoming therapy resistance in castration-resistant PCa (CRPC). By examining the mechanistic underpinnings of hypoxia-driven bone metastasis, we highlight promising translational avenues for improving patient outcomes in advanced PCa. Full article

Cutaneous malignant melanoma is an extraordinarily aggressive and heterogeneous cancer that contains a small subpopulation of tumor stem cells (CSCs) responsible for tumor initiation, metastasis, and recurrence. Identification and characterization of CSCs in melanoma is challenging due to tumor heterogeneity and the lack of specific markers (CD271, ABCB5, ALDH, Nanog) and the ability of cells to dynamically change their phenotype. Phenotype-maintaining signaling pathways (Wnt/β-catenin, Notch, Hedgehog, HIF-1) promote self-renewal, treatment resistance, and epithelial–mesenchymal transitions. Tumor plasticity reflects the ability of differentiated cells to acquire stem-like traits and phenotypic flexibility under stress conditions. The interaction of CSCs with the tumor microenvironment accelerates disease progression: they induce the formation of cancer-associated fibroblasts (CAFs) and neo-angiogenesis, extracellular matrix remodeling, and recruitment of immunosuppressive cells, facilitating immune evasion. Emerging therapeutic strategies include immunotherapy (immune checkpoint inhibitors), epigenetic inhibitors, and nanotechnologies (targeted nanoparticles) for delivery of chemotherapeutic agents. Understanding the role of CSCs and tumor plasticity paves the way for more effective innovative therapies against melanoma. Full article

Adenosine receptors (ARs) are G protein-coupled receptors that are widely expressed across tissues, traditionally associated with cardiovascular, neurological, and immune regulation. Recent studies, however, have highlighted their non-canonical functions, revealing critical roles in metabolism, immunometabolism, and epigenetic regulation. AR subtypes, particularly A2A and A2B, modulate glucose and lipid metabolism, mitochondrial activity, and energy homeostasis. In immune cells, AR signaling influences metabolic reprogramming and polarization through key regulators such as mTOR, AMPK, and HIF-1α, contributing to immune tolerance or activation depending on the context. Additionally, ARs have been implicated in epigenetic modulation, affecting DNA methylation, histone acetylation, and non-coding RNA expression via metabolite-sensitive mechanisms. Therapeutically, AR-targeting agents are being explored for cancer and chronic inflammatory diseases. While clinical trials with A2A antagonists in oncology show encouraging results, challenges remain due to receptor redundancy, systemic effects, and the need for tissue-specific selectivity. Future strategies involve biased agonism, allosteric modulators, and combination therapies guided by biomarker-based patient stratification. Overall, ARs are emerging as integrative hubs connecting extracellular signals with cellular metabolic and epigenetic machinery. Understanding these non-canonical roles may unlock novel therapeutic opportunities across diverse disease landscapes. Full article

Diabetic wounds are a devastating complication that cause chronic pain, recurrent infections, and limb amputations due to impaired healing. Despite advances in wound care, existing therapies often fail to address the underlying molecular dysregulation, highlighting the need for innovative and safe therapeutic approaches. Among these, D-amino acids such as D-tryptophan (D-Trp) have emerged as key regulators of cellular processes; however, their therapeutic potential in diabetic wounds remains largely unexplored. Here, we investigate the therapeutic potential of D-Trp in streptozotocin (STZ)-induced diabetic mice, comparing it with phosphate-buffered saline (PBS) controls and vascular endothelial growth factor (VEGF) as a positive control. Wound healing, inflammation, and histopathology were assessed. Protein and gene expression were analyzed via Western blot and RT-qPCR, respectively. Biolayer interferometry (BLI) measured the binding of D-Trp to hypoxia-inducible factor-1α (HIF-1α). D-Trp accelerated wound healing by modulating extracellular matrix (ECM) remodeling, signaling, and apoptosis. It upregulated matrix metalloproteinases (MMP1, MMP3, MMP-9), Janus kinase 2 (JAK2), and mitogen-activated protein kinase (MAPK) proteins while reducing pro-inflammatory cytokines (tumor necrosis factor-α [TNF-α], interleukin-1β [IL-1β], IL-6). D-Trp also suppressed caspase-3 and enhanced angiogenesis through HIF-1α activation. These findings suggest that D-Trp promotes healing by boosting ECM turnover, reducing inflammation, and activating MAPK/JAK pathways. Thus, D-Trp is a promising therapeutic for diabetic wounds. Full article

Belzutifan is a hypoxia-inducible factor-2α (HIF-2α) inhibitor that received FDA approval in 2021 for treating cancers resulting from von Hippel-Lindau (VHL) disease, including clear cell renal cell carcinoma (ccRCC), followed by approval in 2023 for sporadic ccRCC that has progressed through multiple lines of therapy. HIF-2α is a promising drug target, as VHL is commonly inactivated in ccRCC, which results in HIF-2α-mediated signaling that is considered central to tumorigenesis. Belzutifan has demonstrated efficacy in clinical trials in the first-line and subsequent line settings, and in combination with tyrosine kinase inhibitors. Despite being overall well tolerated, belzutifan has a distinct safety profile because of its unique mechanism of action. Anemia was the most common adverse event observed in clinical trials and is considered an on-target effect. Hypoxia is also frequently observed and commonly results in dose reductions, treatment discontinuation, and supplemental oxygen use. This review summarizes the rates of hypoxia seen in clinical trials of belzutifan in ccRCC. As the cause of hypoxia is not well understood, this review also discusses possible mechanisms of hypoxia based on preclinical studies of the HIF pathway and HIF-2α inhibitors. Finally, this review proposes monitoring and management recommendations for clinicians prescribing belzutifan to ccRCC patients. Full article

Chronic kidney disease (CKD)-associated anemia is a global health concern and is linked to vascular and ocular complications. Hypoxia-inducible factor (HIF) stabilizers, or HIF prolyl hydroxylase inhibitors (PHIs), are promising candidates for the treatment of CKD-associated anemia. Since hypoxia and angiogenesis are involved in eye diseases, this study examined the effects of HIF-PHIs on metabolism and gene expression in retinal pigment epithelium (RPE) cells. Results revealed that PHIs differentially induced angiogenic (VEGFA, ANG) and glycolytic (PDK1, GLUT1) gene expression, with Roxadustat causing the strongest transcriptional changes. However, Roxadustat-induced angiogenic signals did not promote endothelial tube formation. Moreover, it did not induce oxidative stress, inflammation, or significant antioxidant gene responses in ARPE-19 cells. Roxadustat also reduced the inflammatory cytokine response to tumor necrosis factor-α, including IL-6, IL-8, and MCP-1, and did not exacerbate VEGF expression under high-glucose conditions. Overall, Roxadustat triggered complex gene expression changes without promoting inflammation or oxidative stress in RPE cells. Despite these findings, ophthalmologic monitoring is advised during PHI treatment in CKD patients receiving HIF-PHIs. Full article

Background/Objectives: CD318 (also known as CDCP1) is a transmembrane protein that is overexpressed in many cancers and contributes to tumor progression, invasion, and metastasis by activating SRC family kinases through phosphorylation. Emerging evidence also suggests that CD318 plays a role in modulating the tumor immune microenvironment, although its precise mechanism in tumor progression is still not well understood. Methods: To investigate this, we analyzed the expression and immune-related functions of CD318 using the publicly available data from The Cancer Genome Atlas (TCGA) across colorectal adenocarcinoma (COAD), cervical squamous cell carcinoma (CESC), lung adenocarcinoma (LUAD), and pancreatic adenocarcinoma (PAAD). Results: All four cancers exhibited a high level of CD318 expression. Notably, in CESC, LUAD, and PAAD, plasmin-mediated cleavage of CD318 leads to phosphorylation of SRC and protein kinase C delta (PKCδ), which activates HIF1α and/or p38 MAPK. These downstream effectors translocate to the nucleus and promote the transcriptional upregulation of TGFβ1, fostering an immunosuppressive tumor microenvironment through Treg cell recruitment. In contrast, this signaling cascade appears to be absent in COAD. Instead, our analysis indicate that intact CD318 in COAD interacts with the surface receptors CD96 and CD160, which are found on CD8⁺ T cells and NK cells. Conclusions: This interaction enhances cytotoxic immune responses in COAD by promoting CD8⁺ T cell and NK cell activity, offering a possible explanation for the favorable prognosis associated with high CD318 expression in COAD, compared to the poorer outcomes observed in CESC, LUAD, and PAAD. Full article

Osteoclasts, which are derived from myeloid precursors, are essential for physiologic bone remodeling but also mediate pathological bone loss in inflammatory diseases such as periodontitis and rheumatoid arthritis. Lysine-specific demethylase (LSD1/KDM1A) is a histone demethylase that modulates the chromatin landscape via demethylation of H3K4me1/2 and H3K9me1/2, thereby regulating the expression of genes essential for deciding cell fate. We previously demonstrated that myeloid-specific deletion of LSD1 (LSD1LysM-Cre) disrupts osteoclast differentiation, leading to enhanced BV/TV under physiological conditions. In this study, we show that LSD1LysM-Cre female mice are similarly resistant to inflammatory bone loss in both ligature-induced periodontitis and K/BxN serum-transfer arthritis models. Bulk RNA-seq of mandibular-derived preosteoclasts from LSD1LysM-Cre mice with ligature-induced periodontitis revealed the upregulation of genes involved in inflammation, lipid metabolism, and immune response. Notably, LSD1 deletion blocked osteoclastogenesis even under TGF-β and TNF co-stimulation, which is an alternative RANKL-independent differentiation pathway. Upregulation of Nlrp3, Hif1α, and Acod1 in LSD1LysM-Cre preosteoclasts suggests that LSD1 is essential for repressing inflammatory and metabolic programs that otherwise hinder osteoclast commitment. These findings establish LSD1 as a critical epigenetic gatekeeper integrating inflammatory and metabolic signals to regulate osteoclast differentiation and bone resorption. Therapeutic inhibition of LSD1 may selectively mitigate inflammatory bone loss while preserving physiological bone remodeling. Full article

Viola philippica (VP), a traditional Chinese medicinal herb widely used for its antibacterial and antioxidant properties, has recently garnered attention for its potential in skin photoprotection. VP was extracted using glycerol (GLY), 1,3-propanediol (PDO), and 1,3-butanediol (BDO) at concentrations of 30%, 60%, and 90% (w/w) to evaluate its antioxidant and UV-protective properties. The total phenolic content (TPC) and total flavonoid content (TFC) of the nine extracts ranged from 34.73 to 71.45 mg GAEs/g and from 26.68 to 46.68 mg REs/g, respectively, with the highest TPC observed in 90% PDO and the highest TFC in 60% GLY. Antioxidant assays revealed IC₅₀ values of 0.49–1.26 mg/mL (DPPH), 0.10–0.19 mg/mL (ABTS), and 1.58–460.95 mg/mL (OH). Notably, the 60% GLY, 30% PDO, and 90% PDO extracts demonstrated notable protective effects against UVB-induced cell damage, reducing intracellular ROS levels and preventing DNA damage. RNA-seq analysis revealed that the protective effects were associated with the modulation of key molecular pathways, including neutrophil extracellular trap formation and TNF, IL-17, and HIF-1 signaling. These findings suggest that Viola philippica polyol extracts, particularly those using 60% GLY, 30% PDO, and 90% PDO, have promising potential for skin photoprotection and could be utilized as natural antioxidants in cosmetic formulations. Full article

Background: The retina, a light-sensitive tissue of the central nervous system that is located at the posterior part of the eye, is particularly vulnerable to alterations in oxygen levels. In various retinal diseases, such as central retinal vein occlusion, glaucoma, and diabetic retinopathy, hypoxia (a condition of low oxygen levels) is commonly observed. Müller glia, the principal glial cells in the retina, play a crucial role in supporting the metabolic needs of retinal neurons. They are also responsible for sensing oxygen levels and, in response to hypoxia, express Hypoxia-Inducible Factor 1 (HIF-1), a transcription factor that activates signaling pathways related to hypoxia. Methods: In this study, primary rat Müller glial cells were cultured and exposed to a 1% oxygen for 72 h. Following this, immunohistochemical assays were conducted to assess the effects of hypoxia on various parameters, including HIF-1α expression, cell survival, Müller glia-specific markers (CRALBP and GS), gliosis (GFAP expression), apoptosis (caspase-3 expression), cell proliferation (Ki-67 expression), and metabolic stress (indicated by the number of mitochondria per cell). Results: Under hypoxic conditions, a decrease in Müller glial survival and proliferation was observed. Conversely, there was an increase in HIF-1α expression, GFAP expression, caspase-3-positive cells, and the number of mitochondria per cell. However, no significant changes were noted in the expression of the Müller glial markers GS and CRALBP. Conclusions: In conclusion, hypoxia resulted in reduced proliferation and survival of Müller glial cells, primarily due to increased apoptosis and heightened metabolic stress. Full article

Cardiac remodeling in feline hypertrophic cardiomyopathy (HCM) is poorly understood. To investigate underlying molecular mechanisms, we determined microRNA–mRNA interactions, regulatory networks, and upstream regulators using left ventricle (LV) and left atrium (LA) mRNA and microRNA sequencing datasets from cats with HCM and controls. Upstream regulators, molecules, and pathways associated with ischemia, inflammation, fibrosis, and cellular changes were observed in the HCM heart. In both the HCM LV and LA, TNFα, IL1β, and TGFβ were identified as upstream regulators, along with FGF23, THBS4, and FAMB177 as the top increased molecules. Relevant microRNAs included upstream regulator miR-132, enriched miR-124-3p, miR-122b-3p, miR-146-5p (HCM LV and LA), miR-370, miR-1185-5p, miR-12194-3p (HCM LV), miR-153-3p, miR-185-5p, and miR-185-3p (HCM LA). Macrophage pathways were activated, and granulocyte and agranulocyte adhesion and diapedesis were the most connected pathways. The HIF1α signaling pathway in the HCM LV, upstream regulators miR-1-3p and miR-204, and reduced miR-29 and miR-122-5p suggest cardioprotective mechanisms. Observed in the healthy heart and suspected to be involved in cardiac homeostasis were upstream regulators miR-96, inhibited WNT3A and miR-145, as well as miR-140-5p, miR-141-3p, miR-208b-3p, and miR-885-3p. This study provides further insights into the pathogenesis of HCM, and identifies the factors involved in the maintenance of a healthy LV and LA. Full article

Eccrine sweat glands play a vital role in human thermoregulation; however, their self-repair function is minimal. Therefore, developing methods to regenerate and improve sweat gland function that use cultured sweat gland cells presents an urgent issue. The tissue microenvironment, especially hypoxic niches, essentially maintain cell stemness, highlighting the importance of oxygen concentration in the culture environment. Therefore, we evaluated the effects of different oxygen environments on human sweat glands and their regulatory mechanisms. Human eccrine sweat glands express HIF-1α and HIF-2α, suggesting that they respond to hypoxia in vivo. Primary human-derived eccrine sweat gland cells were cultured for two weeks using the spheroid culture method at 0.5%, 2%, 10%, and 21% O₂ concentration. HIF-1, Wnt/β-Catenin, and TGFβ1 signaling increased in sweat gland cells cultured in 0.5% O₂ conditions, along with increased undifferentiated cell marker expression. The results of this study will contribute to in vitro research models of sweat glands and treatment development for damage to sweat glands, including burns. Full article