Search Results (6,396)

The family of Nek kinases has 11 human members that are conserved in their kinase domains but diverse in their regulatory domains. Functionally, they can be associated with diverse aspects of cell cycle regulation, from mitosis and primary cilia function to centrosome disjunction in the G2 phase and checkpoints of the DNA damage response. However, novel functional contexts have emerged in recent years, including regulatory roles of Neks 1, 4, 5, and 10 in mitochondrial metabolic and morphological homeostasis. We recently generated, by CRISPR-Cas9 technology, a DU-145 prostate cancer cell line, with an NEK6 gene knockout. Here, we focus on a detailed characterization of changes in this cell line, in mitochondrial respiration function and morphology. DU-145 NEK6 knockout cells exhibited reduced mitochondrial respiration and a fragmented phenotype in electron microscopy, with reduced mitochondrial cristae numbers. Alterations in mitochondrial architecture and respiration were correlated with increased expression of anaerobic glycolytic proteins (HK2, PFKP, and LDHA) and decreased expression of PDH, an enzyme of aerobic glycolysis. Molecular analysis by Western blot revealed decreased levels of mitochondrial mass and biogenesis protein markers (TOM20, TFAM), without alterations in other markers such as VDAC1/3 or mtDNA copy number in the NEK6 knockout cells. Furthermore, the regulators of mitochondrial fusion/fission are altered in the knockout cells (decrease in the Long-OPA1:Short-OPA1 ratio and DRP1 total level), which is associated with an increase in endoplasmic reticulum–mitochondria contact at ≤20 nm observed in transmission electron microscopy (TEM) image analysis. Using analysis of TEM micrographs, we found an increase in the autophagic structures (autophagosome, amphisome, and autolysosome), with mitochondria as cargo in some structures, which was correlated with a decrease in LC3A/B and an increase in the BECLIN1 total level, and with an increase in acidic vesicles approximation, suggesting that reduction in TOM20 and TFAM without alterations in VDAC1/3 and mtDNA copy number might be related to mitochondrial degradation through autophagy. Together, our data suggest a new role for NEK6 in regulating mitochondrial homeostasis, where its loss alters mitochondrial morphology and respiration, and could be associated with an increase in the degradation of the dysfunctional mitochondria through autophagy. Full article

Osteoporosis is a systemic skeletal disorder characterized by low bone mass, microarchitectural deterioration, and an increased risk of fracture. Its pathogenesis is closely associated with disturbances in energy metabolism, particularly glucose metabolic reprogramming in bone cells. Under osteoporotic conditions, the balance between osteoblasts and osteoclasts is disrupted, accompanied by impaired oxidative phosphorylation, dysregulated glycolysis, and reduced tricarboxylic acid cycle efficiency, ultimately leading to mitochondrial dysfunction. These metabolic alterations result in an insufficient energy supply and accelerate bone loss. Accordingly, the modulation of key enzymes involved in glucose metabolism has emerged as a promising therapeutic strategy. Strategies include the use of natural compounds, traditional Chinese medicine formulas, and specific inhibitors to modulate glucose metabolism processes and related pathways, thereby restoring cellular energy homeostasis and bone remodeling balance. This review summarizes pharmacological agents regulating glucose metabolism and proposes a hierarchical framework for therapeutic prioritization: first, inhibiting pathological glycolysis in osteoclasts (particularly via LDHA and PKM2). Second, restoring oxidative phosphorylation in osteoblasts (e.g., via COX I–V or ATP synthase). And third, employing multi-target traditional Chinese medicine formulas as complementary strategies. By establishing this cell-type-specific and pathway-specific hierarchy, the review aims to provide a theoretical basis for future research on metabolic interventions in bone diseases. Full article

Macrophage migration inhibitory factor (MIF) has been shown to induce M1 macrophage polarization with oxidative stress and associated metabolic reprogramming. Several tautomerase inhibitors were shown to selectively inhibit either MIF’s ketonase or enolase sub-activities. In this study, we aimed to investigate the role of enolase sub-activity in M1 polarization using the selective enolase inhibitor TE-91. We performed in silico molecular docking analysis and physicochemical characterization of TE-91. LPS + IFN-γ-induced RAW264.7 cells were applied as a model for M1 macrophage activation. We performed ROS and nitrite determinations, ELISA, qPCR, and immunoblot analysis, and measured mitochondrial oxygen consumption rate and extracellular acidification rate. Here, we reveal that TE-91 might directly bind to the MIF tautomerase active site. Furthermore, TE-91 reduces M1 activation by enhancing oxidative phosphorylation and reducing the glycolytic activity in LPS + IFN-γ-induced macrophage cells. In the same model, TE-91 reduces TNF-α, IL-6, CCL2, and iNOS mRNA transcription yet fails to modulate PARP1 and SOD2 mRNA transcription. It also decreases ROS, nitrite, and IL-6 production without influencing TNF-α and CCL2 protein production. TE-91 was unable to reduce either HIF-1α mRNA transcription or its protein expression. Finally, TE-91 reduced IL-1β cleavage, without affecting IL-1β protein expression. These results may highlight the importance of tautomerase sub-activities in M1 polarization. Full article

Background/Objectives: Promoting white adipose tissue (WAT) browning into thermogenic beige adipocytes is a promising anti-obesity strategy. Yanggyeoksanhwa-tang (YST) has been used traditionally to alleviate obesity-related conditions. Catalpol and rhoifolin are major bioactive components of Rehmannia glutinosa (Gaertn.) and Lonicera japonica (Thunb.) with known metabolic or anti-inflammatory effects. However, their direct roles in adipocyte browning and the mechanisms via β3-adrenergic receptor (β3-AR) signaling are not well defined, and this study addresses this gap. Methods: To evaluate browning potential, 3T3-L1 adipocytes were treated with catalpol and rhoifolin during differentiation. The expression of browning markers and lipid metabolism or catabolism transcription factors was analyzed using Western blotting and quantitative real-time polymerase chain reaction. The involvement of the β3-AR and adenosine monophosphate–activated protein kinase (AMPK) signaling pathways was further validated using specific agonists and antagonists. Results: Both compound treatments significantly upregulated beige-specific (Cd137, Cited, Tbx1, Cidea, Fgf21, Tmem26) and mitochondrial biogenesis markers (Cox4, Nrf1, Tfam), accompanied by a marked increase in thermogenic markers (UCP1, PGC-1α, Prdm16). Concurrently, lipolysis-related genes such as Atgl, Hsl, and Plin1 were elevated, while lipogenesis targets (Fasn, Lpl, Srebf1, Acaca) were downregulated through activation of the β3-AR signaling pathway. Conclusions: These findings suggest that catalpol and rhoifolin, key phytochemicals of YST, promote WAT browning and lipolysis. Our findings indicate that these compounds induce browning and modulate metabolism via the β3-AR pathway. These results serve as a cornerstone for natural anti-obesity therapy, pending further validation in vivo and clinical studies. Full article

Tumour necrosis factor-alpha (TNF-α) disrupts bioenergetic homeostasis in skeletal muscle cells through the suppression of ion-dependent ATPase activities, mitochondrial depolarisation, and impairment of antioxidant defences. Carvacrol, a phenolic monoterpenoid constituent of thyme and oregano essential oil, has been shown to exert cytoprotective effects in TNF-α-challenged L6 rat myoblasts. The mechanistic basis of these effects, specifically the relationship between membrane-associated ATPase function, mitochondrial polarisation status, and transcriptional regulation of metabolic stress-response genes, has not been formally characterised. L6 rat myoblasts were exposed to TNF-α (10 ng/mL, 1 h), then treated with carvacrol (6.25 µg/mL, 24 h) in a post-inflammatory rescue paradigm. Cell viability (MTT), membrane integrity (LDH), ion-dependent ATPase activities (Na⁺/K⁺, Ca²⁺, Mg²⁺), antioxidant enzyme activities (catalase, SOD), mitochondrial membrane potential (Muse™ MitoPotential flow cytometry), and SIRT1/AMPK mRNA expression were quantified. TNF-α significantly suppressed Na⁺/K⁺, Ca²⁺, and Mg²⁺-dependent ATPase activities (all p < 0.001), consistent with impaired membrane-associated bioenergetic function. Post-TNF-α carvacrol treatment partially restored all three ATPase activities (p < 0.05) and reduced the proportion of mitochondrially depolarised cells from 31.65 ± 4.25% to 19.0 ± 2.6% (p < 0.05). LDH release, catalase activity, and SOD activity were also significantly modulated. At the transcriptional level, carvacrol increased SIRT1 mRNA by 1.6-fold and AMPK mRNA by 2.0-fold relative to TNF-α-treated cells. An integrative bioenergetic model is proposed in which carvacrol’s membrane-intercalating properties restore the phospholipid environment required for ATPase conformational cycling, attenuating the Ca²⁺ overload that drives mitochondrial permeability transition, and thereby partially preserving Δψm. Transcriptional upregulation of SIRT1 and AMPKα may represent an adaptive response to residual energetic stress. The mechanistic relationships among these endpoints and the causal contribution of SIRT1 and AMPK to observed bioenergetic changes require protein-level and pathway-specific experimental validation. Full article

Females with iron overload suffer from follicular dysplasia, and effective therapeutic strategies for preserving fertility remain lacking. As a natural aliphatic polyamine, spermidine exerts antioxidant activity and plays an anti-ferroptosis role in the pathogenesis of various diseases. However, the role and underlying mechanism of spermidine in iron overload-induced ovarian ferroptosis remain largely elusive. This study aimed to investigate the therapeutic potential of spermidine against iron overload-induced ferroptosis in ovarian granulosa cells and elucidate its molecular mechanism. As a result, iron overload models were established in female mice (in vivo, ferrous sulfate) and porcine ovarian granulosa cells (in vitro, ferric ammonium citrate), with spermidine administered at 3 mM (in vivo) or 150 μM (in vitro). Ferritin heavy chain (FHC) and solute carrier family 7 member 11 (SLC7A11) silencing were performed via siRNA transfection, and relevant controls were set. In vivo studies showed that spermidine elevated serum estradiol and progesterone levels, enhanced ovarian catalase (CAT) and superoxide dismutase (SOD) activities, improved granulosa cell mitochondrial morphology, and increased estrous cycle regularity from 35.6% (high-iron group) to 63.1%. In vitro, spermidine improved ferric ammonium citrate (FAC)-impaired cell viability; attenuated reactive oxygen species (ROS) accumulation; upregulated FHC, Nrf2/p-Nrf2/GPX4, SLC7A11 and anti-müllerian hormone (AMH) expression; and inhibited excessive autophagy (decreased LC3BII/I ratio). Mechanistically, spermidine activated AKT-mediated autophagy, modulated iron homeostasis and glutathione (GSH) synthesis via FHC, alleviated ferroptosis-related Nrf2/p-Nrf2/HO-1 pathway overactivation, reduced lipid peroxidation and DNA damage, and restored mitochondrial function. SLC7A11 silencing disrupted glutathione metabolism, induced mitochondrial ROS accumulation, and inhibited autophagy. Proteomic analysis identified microsomal glutathione S-transferase 3 (MGST3) as a potential key downstream target of spermidine in suppressing SLC7A11-mediated ferroptosis. This study reveals a novel therapeutic strategy wherein spermidine protects against ovarian ferroptosis and preserves ovarian function by regulating iron homeostasis through the FHC/SLC7A11 axis. Full article

Semaglutide, a long-acting glucagon-like peptide-1 receptor agonist (GLP-1RA), has transformed obesity and diabetes management. However, its expanding use among reproductive-age women raises concerns about potential effects on early placental development. We examined semaglutide’s impact on two human trophoblast cell lines: Swan71 (invasive extravillous) and BeWO (syncytiotrophoblast-like). Cells were treated with semaglutide (100 nM) for 24 h, and proliferation, viability, mitochondrial respiration, oxidative stress, signaling pathways, and invasiveness were evaluated. Semaglutide significantly reduced proliferation in Swan71 cells and increased it in BeWO cells, with no significant change in viability for Swan71 and a slight increase for BeWO. Western blot analysis revealed altered phosphorylation of key signaling proteins, including mTOR, p70S6K, 4EBP1, AKT, and ERK, as well as increased AMPK phosphorylation, indicating a shift toward catabolic signaling. Reactive oxygen species (ROS) accumulation increased markedly, accompanied by altered oxygen consumption rates—reduced in Swan71 cells and elevated in BeWO cells. Functionally, semaglutide suppressed Swan71 invasion through Matrigel by approximately three-fold. These findings suggest that semaglutide induces oxidative and metabolic stress in trophoblasts and is associated with altered mTOR-mediated signaling and reduced invasive potential. Such cellular alterations may contribute to compromised placental development and uterine vascular remodeling if exposure occurs near conception. While clinical data remain limited, this study provides mechanistic insight supporting caution in the use of semaglutide during the periconception period and underscores the need for targeted reproductive safety studies. Full article

Background/Objectives: Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by complex and interconnected pathophysiological mechanisms, including mitochondrial dysfunction, oxidative stress, neuroinflammation, lysosomal impairment, and altered neurotransmitter metabolism. Unlike cerebrospinal fluid or blood, urine offers a truly non-invasive source of biomarkers, reflecting systemic metabolic changes and renal protein excretion linked to neurodegeneration. This review aims to critically synthesize current evidence on urinary biomarkers in PD and to organize this heterogeneous literature into pathophysiologically meaningful domains. Methods: A comprehensive literature search of human studies investigating urinary biomarkers in PD was performed. Eligible studies were comprehensively analyzed and classified according to dominant biological pathways. To facilitate interpretation, findings were organized into six thematic domains: genetic and protein-based biomarkers; metabolic pathways and mitochondrial dysfunction; oxidative stress and neuroinflammation; gut–brain-axis-related metabolites; hormonal and systemic biomarkers; and emerging exploratory markers. Results were summarized in domain-specific tables and integrated using a conceptual framework. Results: A total of 32 human studies met the inclusion criteria, revealing diverse urinary molecular signatures associated with PD across multiple biological domains. Genetic and protein-based markers, including LRRK2-related proteins, α-synuclein species, and lysosomal lipids, showed potential for disease stratification. Metabolomic studies consistently identified alterations in acylcarnitines, organic acids, and amino acid metabolism, reflecting mitochondrial dysfunction. Biomarkers related to oxidative stress, immune activation, gut microbiota metabolism, and hormonal regulation further highlighted the systemic nature of PD. However, most individual biomarkers lacked disease specificity and exhibited methodological heterogeneity. Conclusions: Current evidence supports urine as a valuable source of systemic biomarkers reflecting multiple pathophysiological processes in PD. While single urinary markers remain insufficient for clinical application, integrated omics-based approaches—particularly metabolomics and peptidomics/proteomics—hold promise for identifying combinatorial biomarker signatures. Future longitudinal and standardized studies are required to enhance specificity and translational potential for non-invasive diagnosis and disease monitoring in PD. Full article

Type 2 diabetes mellitus is a relevant cardio–renal–metabolic disorder in which chronic low-grade inflammation and oxidative stress have a crucial function in linking insulin resistance, endothelial dysfunction, β-cell impairment, and progressive organ injury. In this context, nutrition has emerged as a key modifiable determinant of metabolic homeostasis, capable of influencing inflammatory signalling, redox balance, mitochondrial function, and gut microbiota–host interactions. The objective of this review is to critically summarise the mechanistic connections among inflammation, oxidative stress, and diabetes progression, and to investigate how dietary factors and patterns, as well as nutrition-responsive biomarkers, influence these pathways and their cardiorenal consequences. We discuss the effects of macronutrient quality, dietary fibre, fatty acids, polyphenols, and specific micronutrients, including vitamin C, vitamin E, selenium, zinc, and magnesium, as well as the role of Mediterranean, DASH, and plant-based diets in improving glycaemic control, endothelial function, and cardio-renal risk profiles. We also summarise established and emerging biomarkers of inflammation and oxidative stress that may improve risk stratification and the evaluation of nutrition-based interventions. Overall, current evidence supports a shift from a purely glucose-centred approach toward an integrated model in which dietary modulation of inflammatory and oxidative pathways helps reduce cardiovascular and renal risk. However, heterogeneity of interventions, variability in biomarker assessment, and interindividual differences in dietary response represent major limitations. Future research should focus on biomarker-informed, precision-oriented nutritional approaches integrated within contemporary cardio–renal–metabolic care. Full article

Background/Objectives: Excessive dietary inorganic phosphate (Pi) as a food additive poses potential health risks. Methods: This study investigated the impact of excessive dietary inorganic phosphate on intestinal and immune homeostasis in mice using gradient Pi exposure combined with an inflammatory model. Results: Pi overload induced atrophy in the thymus, spleen, and kidney; damaged the intestinal barrier; reduced the villus height-to-crypt-depth ratio; and decreased goblet cell numbers. Altered levels of serum sIgA and IgE, as well as intestinal IgA, IgG, IgE, and IgM, together with decreased IFN-α, indicated altered levels of immunoglobulins and cytokines under Pi treatment. Proteomic analysis revealed differential expression of key proteins, including CNTFR and Bcl2l1 in the JAK/STAT pathway and metabolic regulators CPT1α and IDH1, when comparing Pi-treated mice with the control group. Conclusions: These preliminary findings suggest that Pi may affect intestinal mucosal barrier function and systemic immune response through immune regulation and mitochondrial metabolic pathways, providing preliminary insight into the potential health implications of Pi overconsumption in humans. Full article

Pyrrolizidine alkaloids (PAs), a category of naturally occurring secondary metabolites, are commonly found in various botanical sources. Accumulating evidence indicates that PAs and their biologically active metabolites can interact with cellular components and trigger a variety of toxic effects in animals and humans. Notably, PAs exhibit significant hepatotoxic potential via nutritional supplements, environmental dissemination, food chain contamination, and broader ecological pollution. In this review, we summarize PA-induced hepatotoxicity in humans and animals and the underlying molecular mechanisms. It involves oxidative stress, mitochondrial dysfunction, apoptosis, ER stress, inflammation, autophagy, and ferroptosis. Several key signaling pathways, such as nuclear factor-erythroid 2 related factor 2 (Nrf2), mitogen-activated protein kinase (MAPK), protein kinase RNA-like endoplasmic reticulum kinase (PERK), toll like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB), transforming growth factor beta (TGF-β), p53, farnesoid X receptor (FXR), and pregnane X receptor (PXR), are also implicated. Furthermore, this review discusses diagnostic approaches, metabolic activation pathways, and detoxification strategies targeting PA-induced liver injury. Collectively, this review provides a comprehensive understanding of the molecular basis of PA hepatotoxicity and underscores the urgent need for improved risk assessment, early diagnosis, and effective detoxification interventions to mitigate PA-related liver diseases in humans and animals. Full article

Cisplatin-induced ototoxicity is a permanent, bilateral sensorineural hearing loss occurring in up to 80% of treated patients. Its defining and clinically challenging feature is the progressive worsening of auditory function that continues well after chemotherapy has ended, a trajectory that cannot be explained by cumulative dose alone. This article is a comprehensive review of the present research studies on mechanisms that are responsible for this post-treatment progression. The cochlea, unlike other organs, appears to be unable to eliminate platinum (the active divalent metal ion released from cisplatin and responsible for its cytotoxic and ototoxic effects): traces of it can be found in human temporal bone tissue even more than 18 months after last infusion, and bone might serve as a long-term systemic reservoir. Within the inner ear, platinum accumulates preferentially in the stria vascularis, impairing endocochlear potential and outer hair cell function. Retained platinum sustains cascading effects including sustained NOX3-dependent oxidative stress, mitochondrial dysfunction, ongoing genotoxic injury to non-regenerative cells, and the early loss of ribbon synapses that precipitates delayed spiral ganglion neurodegeneration. Pharmacogenetic variability in platinum transport and antioxidant metabolism further modulates individual susceptibility. These findings support lifelong audiological surveillance and provide a basis for designing strategies that can protect hearing without compromising the essential anticancer efficacy of cisplatin therapy. Full article

The tumor microenvironment (TME) is a highly adaptive and heterogeneous niche in which cancer stem cells (CSCs) promote immune evasion, metastatic dissemination, and therapy resistance. Among the mechanisms that support this phenotype, mitochondrial hijacking has emerged as a central strategy through which CSCs reprogram immune and stromal cells to favor tumor progression. This review synthesizes current evidence on how CSCs exploit mitochondrial transfer, particularly via tunneling nanotubes (TNTs) and extracellular vesicles (EVs), to impair antitumor immunity and remodel the metastatic niche. CSCs display marked metabolic plasticity, shifting between glycolysis and oxidative phosphorylation (OXPHOS) in response to environmental stress. They exploit this adaptability by transferring mitochondria and mitochondrial components to recipient cells, including tumor-associated macrophages (TAMs) and cytotoxic T cells, thereby disrupting ATP production, increasing oxidative stress, and skewing immune polarization. This mitochondrial hijacking contributes to an immunosuppressive milieu, stabilizes HIF-1α, and enhances PD-L1 expression, ultimately weakening T-cell activity and reinforcing CSC survival. EVs add another layer of regulation by transporting bioactive cargo, including oncogenic microRNAs (miRNAs) and mitomiRs such as miR-21, miR-210, and miR-34a. These molecules modulate mitochondrial gene expression, reshape immune signaling, and reinforce CSC phenotypes through autocrine and paracrine loops. Single-cell and spatial transcriptomic approaches have further revealed metabolic heterogeneity within CSC–immune synapses, identifying “metabolic hotspots” associated with profound immune dysfunction. Therapeutic strategies targeting OXPHOS, EV biogenesis, and miRNA activity are therefore being explored. In parallel, mitochondria-associated proteins such as TSGA10 may also contribute to CSC-driven immunometabolism regulation and deserve further investigation. Targeting downstream heterogeneity is like cutting the branches of a weed. Targeting the upstream mechanisms of mitochondrial hijacking and miRNA crosstalk aims to destroy the root (CSC plasticity) that generates the heterogeneity and drives therapy resistance in the first place. This review highlights mitochondrial hijacking and miRNA-mediated reprogramming as central determinants of CSC-driven immune escape and proposes a framework for precision interventions targeting CSC–immune interactions in metastatic cancer. Full article

Methylglyoxal (MG) is a reactive dicarbonyl compound generated mainly as a byproduct of glycolysis. Excess accumulation of MG can promote protein glycation and the formation of advanced glycation end-products (AGEs), which have been associated with oxidative stress, inflammation, mitochondrial dysfunction, and cellular damage. These processes are implicated in the development of several chronic conditions, including diabetes, neurodegenerative disorders, cardiovascular disease, and age-related decline. The glyoxalase system, comprising Glyoxalase I (Glo1) and Glyoxalase II (Glo2), serves as a key cellular defense mechanism that detoxifies MG and helps maintain dicarbonyl homeostasis. Among these enzymes, Glo1 catalyzes the conversion of MG into less reactive intermediates in a glutathione (GSH)-dependent manner. A range of natural compounds and dietary phytochemicals, including sulforaphane, resveratrol, α-lipoic acid, selenium, vitamin D3, and N-acetylcysteine, have been reported to modulate Glo1 activity through transcriptional regulation, antioxidant effects, or support of intracellular GSH levels. Evidence from preclinical and limited human studies suggests that these compounds may help reduce MG burden and AGE formation, although their effects are often indirect and context-dependent. However, several challenges remain, including variable bioavailability, dose-dependent responses, disease-specific differences in Glo1 regulation, and the lack of standardized biomarkers and adequate clinical validation. This review examines the MG–Glo1 axis as a mechanistic framework linking metabolic stress to disease and evaluates natural compounds as context-dependent modulators of this pathway. By integrating mechanistic insights with emerging in vivo and clinical evidence, this work highlights the potential, while acknowledging the limitations, of targeting Glo1 as a translational strategy for managing glycation-associated disorders. Full article

High-altitude hypoxic adaptation in mammals involves complex molecular mechanisms, with non-coding RNAs (ncRNAs) increasingly reported to participate in hypoxia-related regulation. However, the contribution of circRNAs in cardiac adaptation to chronic hypoxia remains largely unexplored. This study performed an integrative competitive endogenous RNA (ceRNA) analysis to investigate circRNA-mediated regulatory networks in the hearts of Tibetan pigs and Yorkshire pigs maintained under high- and low-altitude conditions, using four comparison groups (TH, TL, YH, and YL). Using Ribo-Zero RNA sequencing, we identified 961 circRNAs in heart tissues, with 358 differentially expressed circRNAs (DE-circRNAs) detected across the four groups. Functional enrichment analysis revealed that their host genes were associated with hypoxia-related pathways, including HIF-1, VEGF, AMPK, and autophagy, critical for energy metabolism and mitochondrial function. A HIF-1-specific ceRNA network was constructed, identifying key axes including circDUSP16–ssc-miR-671-5p–CAMK2A, circTLK1–ssc-miR-331-3p–SERPINE1, and circTLK1–novel-miR-624–ENO1. JASPAR analysis predicted potential HIF-1α binding sites in the promoters of ENO1, SERPINE1, and CAMK2A, supporting their regulatory roles. These findings provide a transcriptomic overview of circRNA expression patterns in pig heart tissues under different altitude conditions and prioritize candidate ceRNA relationships for further functional investigation. Full article