Search Results (442)

Manganese ions (Mn²⁺) are an essential trace element within organisms spanning the entire tree of life. It has reported that Mn²⁺ exerts strong immunocompetence effects and exhibits antiviral effects against various human and animal viruses, including DNA and RNA viruses. Recently, Mn²⁺ has been found to be involved in the activation of the innate immune DNA-sensing cyclic GMP-AMP synthase (cGAS) stimulator of interferon genes (STING) pathway and subsequent antiviral function. However, the antiviral mechanism of Mn²⁺ remains unclear. In the current study, the results suggest that the cGAS-STING pathway is essential for Mn²⁺ to promote interferon (IFN) signaling, but it is not essential for triggering antiviral functions. After knocking out the STING or interferon regulatory factor 3 (IRF3) gene, Mn²⁺ still retains its antiviral activity against herpes simplex virus type 1 (HSV-1) and vesicular stomatitis virus (VSV). Furthermore, the results from transcriptomic analysis indicate that Mn²⁺ can induce a significant change in the apoptotic process in STING⁻/⁻ 3D4/21 cells. Mn²⁺ can induce cell apoptosis through the oxidative stress pathway, and inhibiting the apoptotic signal could suppress Mn²⁺-mediated antiviral activity in STING⁻/⁻ 3D4/21 cells. Additionally, dual knockout of IRF3 and caspase3, resulting in concurrent loss of IFN and apoptotic signals, eliminates the antiviral effects of Mn²⁺. In summary, the current study suggests that Mn²⁺ could exert antiviral effects not only through the cGAS-STING-IFN pathway but also via the reactive oxygen species (ROS)-apoptosis pathway. Full article

(1) Background: The “Bider” marking refers to the symmetrical black stripes distributed on the shoulder blades of Dun Mongolian horses, representing an ancestral trait of significant genetic value. However, the molecular mechanisms underlying its formation remain unclear. This study aims to elucidate the molecular basis of these markings by comparing transcriptomic differences in skin tissues from variously pigmented areas of Mongolian horses’ “Bider” patterns. (2) Methods: Using three Dun Mongolian horses as subjects, skin tissue samples were collected from their shoulders (dark-marked and light-marked areas), dorsal midline, and croup regions for transcriptome sequencing. Differentially expressed genes were identified based on sequencing data, followed by Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Key findings were validated through quantitative reverse transcription polymerase chain reaction (qRT-PCR). (3) Results: The sequencing yielded approximately 893 million high-quality clean reads, with an overall alignment rate exceeding 96%. A total of 140 to 775 differentially expressed genes were identified. GO enrichment analysis revealed that these genes were significantly enriched in biological processes related to pigment metabolism, skin and hair follicle development, signal transduction (including calcium and cyclic guanosine monophosphate (cGMP) signaling), and immune regulation. KEGG analysis further indicated that multiple pathways closely associated with pigment regulation, including the calcium signaling pathway, tyrosine metabolism, cyclic adenosine monophosphate (cAMP) signaling pathway, and melanoma pathway, were significantly enriched across different tissue comparison groups, suggesting their potential key roles in coat color phenotype formation. The reliability of the sequencing data was corroborated by the results of qRT-PCR validation. (4) Conclusions: This study conducted a transcriptome analysis of skin samples from various pigmented regions of the Dun Mongolian horse’s Bider marking, revealing that the formation of this marking is associated with the differential expression of numerous genes and is co-regulated by multiple pigment-related signaling pathways. Full article

Background/Objectives: Cyclic dinucleotide stimulator of interferon genes (STING) agonists have emerged as potential agents in cancer immunotherapy, but their clinical applications are limited by relatively poor pharmacokinetic properties. Methods: A luciferase reporter assay was employed to screen delivery peptides capable of promoting cellular activating effect of cyclic dinucleotide STING agonists. The potent candidates were further confirmed by enzyme-linked immunosorbent assay (ELISA), real-time quantitative PCR (qPCR) and Western blotting analysis. Colon and melanoma cancer mouse models were used to examine the antitumor efficacy of the delivery peptides with cyclic GMP–AMP (cGAMP) as a therapeutic agents or vaccine adjuvant. Results: We identify a class of STING agonist delivery peptides that efficiently facilitate cytosolic delivery of cyclic dinucleotide STING agonists and promote STING activation by forming peptide coacervates. Intratumoral administration of Sti3-4A and cGAMP effectively suppressed tumor growth and promoted antitumor immune response. Furthermore, the conjugation of tumor-specific antigen peptides with Sti3-4A promoted cytosolic co-delivery of antigen peptides and cGAMP, thus significantly boosting APC maturation, antigen cross-presentation, and T cell responses to peptide antigens. Prophylactic and therapeutic immunization with the conjugated peptides and cGAMP inhibited tumor growth in multiple murine tumor models. Conclusion: These findings establish STING agonist delivery peptides as a versatile platform for cancer immunotherapy. Full article

The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway serves as a central innate immune signaling axis in host defense against DNA virus infections, and RNA viruses have also evolved diverse strategies to counteract this pathway. Encephalomyocarditis virus (EMCV), a zoonotic RNA virus, utilizes its 2C protein to antagonize RIG-I-like receptor-mediated type I interferon signaling and induce autophagic degradation of calcium binding and coiled-coil domain 2, thereby evading host antiviral immunity. However, the precise molecular mechanism by which EMCV 2C protein modulates the cGAS-STING pathway remains incompletely understood. Herein, we show that EMCV infection reduces the expression of cGAS and STING proteins, and its 2C protein significantly suppresses the production of IFN-β triggered by poly(dA:dT) or viral infection, as well as the mRNA expression of interferon-stimulated genes. Mechanistically, 2C protein binds to STING via its ATPase domain and facilitates K48-linked polyubiquitination and proteasomal degradation of STING, while dominantly interfering STING translocation to the Golgi apparatus and the formation of STING-TBK1-IRF3 complex, thereby blocking STING-mediated IFN-β signal transduction at multiple levels. This study reveals a novel mechanism by which the EMCV 2C protein suppresses the host antiviral response by targeting STING and promoting its ubiquitination and degradation. This finding deepens understanding of the immune evasion mechanism of EMCV and provides a theoretical foundation for the development of antiviral therapies targeting the 2C protein of picornaviruses. Full article

Autophagy is a fundamental lysosome-dependent degradation process that maintains cellular homeostasis in response to stress. VSP34 (Vacuolar Protein Sorting 34, PIK3C3) is the only class-III phosphatidylinositol 3-kinase and generates phosphatidylinositol 3-phosphate (PI3P) for auto-phagosome nucleation and maturation. Thus, it provides a critical adaptive survival pathway for cells that are experiencing metabolic stress. The VPS34–autophagy axis plays dual roles in cancer, which depend on the context: it can restrain early tumorigenesis, but in established tumors, it can promote survival in conditions of hypoxia, nutrient deprivation, and therapeutic pressure. Moreover, VPS34 shapes the tumor microenvironment (TME) through its influence on both immune and cancer cells by modulating autophagy, cGAS-STING (cyclic GMP-AMP synthase Stimulator of Interferon Genes), and STAT1 pathways. VPS34 inhibition has been reported to induce an interferon response that increases CD8⁺ T and natural killer (NK) cell infiltration and converts cold tumors into hot ones. This behavior suggests that combining VPS34 inhibitors with cancer immunotherapies could be beneficial. In this review, we summarize the molecular functions and regulations of VPS34 in autophagy and discuss recent advances linking VPS34 to tumor and cancer immunotherapy. Full article

Ginkgetin (GK) is a naturally occurring biflavonoid predominantly isolated from Ginkgo biloba and has attracted increasing attention because of its broad pharmacological activities. Structurally, GK belongs to the 3′-8″-linked biflavone subclass, which distinguishes it from other biflavonoids like amentoflavone (the parent compound of this subclass) and its monomeric counterparts such as apigenin. This unique C-C linked dimeric architecture confers distinct molecular planarity and lipophilicity, contributing to its enhanced membrane permeability and multitarget engagement capabilities. GK has been shown to exert pleiotropic biological effects in preclinical studies, including anti-inflammatory, antioxidant, antifibrotic, anticancer, neuroprotective, cardioprotective, metabolic regulatory and antibacterial activities. Mechanistically, preclinical evidence indicates that GK functions as a multitarget modulator of key signaling pathways involved in oxidative stress, inflammation, cell death and tissue remodeling, such as nuclear factor erythroid 2–related factor 2/heme oxygenase-1 (Nrf2/HO-1), nuclear factor kappa-B(NF-κB), Janus kinase/signal transducer and activator of transcription(JAK/STAT), mitogen-activated protein kinases(MAPKs), AMP-activated protein kinase/mechanistic target of rapamycin(AMPK/mTOR), phosphoinositide 3-kinase/protein kinase B(PI3K/Akt) and cyclic GMP-AMP synthase–stimulator of interferon genes(cGAS–STING). Notably, GK has been observed to display context-dependent regulation of cell fate decisions, including apoptosis, autophagy and ferroptosis, thereby enabling the selective elimination of pathological cells while preserving normal tissue function. Preclinical studies further demonstrate that GK exhibits therapeutic potential across diverse disease systems, including cancer, metabolic disorders, cardiovascular diseases, neurological disorders and musculoskeletal diseases. In addition, emerging evidence highlights its antibacterial and antivirulence properties through the inhibition of biofilm formation and quorum sensing. It is crucial to note, however, that this promising profile is predominantly derived from preclinical studies, and clinical evidence in humans remains to be established. Despite these promising findings, the clinical translation of GK remains limited by challenges related to pharmacokinetics, bioavailability and druggability. This review systematically summarizes the chemical characteristics, pharmacological activities and molecular mechanisms of GK, with an emphasis on its multitarget actions and therapeutic potential across disease systems, and discusses current limitations and future perspectives to facilitate the rational development of GK-based interventions. Full article

Background: Aging-related cognitive decline is closely associated with microglial senescence and the resulting chronic neuroinflammation. Emerging evidence identifies the cyclic GMP-AMP synthase–stimulator of interferon genes (cGAS-STING) pathway as a pivotal innate immune signaling pathway linking DNA damage to cellular senescence and the senescence-associated secretory phenotype (SASP), particularly in microglia. Targeting the formation or selective clearance of senescent cells thus emerges as a promising therapeutic approach to ameliorate cognitive dysfunction. Resveratrol has shown promise in modulating immune response and exerting anti-aging effects. However, the therapeutic potential and underlying mechanisms of resveratrol in mitigating age-associated microglial senescence and cognitive decline are not fully understood. Methods: In the present study, we employed a well-established murine model of accelerated aging induced by chronic intraperitoneal injection of D-galactose (D-gal) to elicit pronounced senescence-associated phenotypes and neuroinflammation. Resveratrol was administered via oral gavage daily for three weeks following D-gal injections. Behavioral assays were conducted to assess cognitive performance. Immunohistochemistry, quantitative PCR, and Western blot analyses were used to evaluate markers of cellular senescence, microglial activation and pro-inflammatory cytokine expression. In addition, in vitro assays in cultured microglia coupled with RNA sequencing were used to investigate the downstream signaling events following resveratrol treatment. Results: Chronic D-gal treatment induced significant cognitive impairment, enhanced microglial activation, elevated pro-inflammatory cytokine levels, and increased markers of cellular senescence in the brain. Resveratrol administration remarkably attenuated these effects, as evidenced by improved memory performance, reduced microglial senescence markers, and suppressed expression of Cxcl-10, Il-1β, and other SASP factors. Mechanistically, unbiased transcriptomic analysis revealed that the cGAS-STING signaling and neuroinflammation pathways were prominently dysregulated with double-stranded DNA-induced cellular senescence, which was effectively normalized by resveratrol in cultured microglia. Interestingly, resveratrol inhibited the translocation of STING from the endoplasmic reticulum to the Golgi apparatus and suppressed phosphorylation of TBK1, thereby blocking downstream STING signaling. Conclusions: These findings demonstrate that resveratrol mitigates microglial senescence and neuroinflammation and preserves cognitive function in D-gal-induced aging mice, at least partly through modulation of the cGAS-STING signaling. Therefore, targeting this pathway may represent a promising therapeutic strategy for age-related neuroinflammatory and cognitive disorders. Full article

The field of immunometabolism highlights the intricate interplay between immunity and metabolism. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway is a central component of innate immunity that detects double-stranded DNA (dsDNA) from a range of sources, including pathogenic and host-derived DNA. It is now recognized that the cGAS-STING pathway has broad implications in a variety of human conditions including cancer, age-related diseases, and autoimmune disorders. Given the abundance and diversity of lipids across cellular compartments serving as structural components and signaling molecules, it is unsurprising that lipid metabolism influences the regulation of cGAS-STING signaling. Lipids can directly alter signaling protein dynamics through interactions within membrane compartments, while alterations in lipid metabolism can remodel multiple cell-intrinsic signaling cascades. Here, we summarize emerging concepts and recent discoveries that have advanced our understanding of how lipid metabolism and lipids regulate the cGAS-STING pathway. Full article

Background: Abnormal activation of the NRF2-cGAS-STING-NF-κB pathway can trigger an inflammatory cascade in rheumatoid arthritis (RA). Curcumin (CUR), a polyphenolic compound extracted from turmeric, possesses anti-inflammatory activity, but whether it can modulate this pathway to ameliorate RA remains unclear. This study aims to elucidate whether CUR inhibits the inflammatory response in synovial fibroblasts (MH7A) by suppressing the NRF2-cGAS-STING-NF-κB signaling cascade. Methods: An RA inflammatory model was constructed by stimulating MH7A cells with 20 ng/mL tumor necrosis factor (TNF). Groups included a control group, a model group, a methotrexate positive control group [MTX(methotrexate), 10 μmol/L], and curcumin treatment groups at varying concentrations (10–100 μmol/L). Cell viability was assessed using the CCK-8(Cell Counting Kit-8) assay. Cell migration and invasion capabilities were evaluated via scratch wound healing and Transwell assays, respectively. Apoptosis was detected by flow cytometry. mRNA and protein expression levels of NRF2(Nuclear factor erythroid 2-related factor 2), cGAS(cyclic GMP-AMP synthase), STING(stimulator of interferon genes), and NF-κB(nuclear factor kappa-light-chain-enhancer of activated B cells) were measured using qRT-PCR and Western blot, respectively. Protein localization was determined by immunofluorescence. Results: Compared to the model group (TNF-induced), the cell migration rate in the curcumin (CUR) groups was significantly decreased (p < 0.001), with a particularly marked reduction observed at a concentration of 50 μmol/L. Furthermore, as the concentration of curcumin increased, cell invasion capacity showed a significant dose-dependent decline. The apoptosis rate also significantly decreased with increasing curcumin concentrations, demonstrating a clear concentration-dependent effect. Mechanistically, curcumin treatment significantly upregulated the expression of NRF2 and inhibited the activation of its downstream cGAS-STING-NF-κB signaling pathway. Specifically, both mRNA and protein expression levels of NRF2 were markedly elevated (p < 0.001), while the mRNA and protein levels of cGAS, STING, and NF-κB were all significantly reduced (p < 0.001). Conclusions: Curcumin (CUR) can effectively inhibit the inflammatory response of synovial fibroblasts by activating the expression of NRF2 and subsequently suppressing the cGAS-STING-NF-κB signaling pathway. This study provides a new molecular mechanism target for curcumin in the treatment of RA and offers a theoretical basis for the intervention of autoimmune diseases with natural products. Full article

Hypertension remains a major global health challenge, and pharmacological therapy is often constrained by tolerability issues. Adjunctive approaches targeting the nitric oxide synthase and soluble guanylate cyclase–cyclic guanosine monophosphate (sGC–cGMP) pathway may offer additional benefits. This study investigated the efficacy and safety of a nutraceutical formulation combining grape pomace extract (Taurisolo^®) and L-arginine in patients with grade 1 and grade 2 hypertension. The formulation was designed to enhance nitric oxide (NO) bioavailability and support sGC–cGMP signaling. Taurisolo^®, a polyphenol-rich extract, is known for its antioxidant and endothelial-protective properties, while L-arginine serves as the physiological substrate for endothelial NO synthase. Clinical outcomes included blood pressure changes, renal function parameters, and health-related quality of life assessed through the SF-12 questionnaire. Supplementation with Taurisolo^® plus L-arginine resulted in significant and sustained reductions in systolic and diastolic blood pressure, with renal function remaining stable throughout the study. Participants also reported meaningful improvements in perceived health, emotional well-being, vitality, and social functioning. The intervention was well tolerated, with no major adverse effects. These findings support the potential of Taurisolo^® combined with L-arginine as a safe and effective adjunctive strategy to conventional antihypertensive therapy, warranting further mechanistic investigation. Full article

This study aimed to investigate the impacts of chestnut tannin (CT) on growth performance, immune response, and intestinal health of broilers challenged with necrotic enteritis (NE) through the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-ferroptosis pathway. A total of 240 one-day-old male Cobb 500 broilers (44.54 ± 0.51 g) were randomly divided into four groups, including a Control group, NE group, 500 mg/kg CT group (L-CT), and 1000 mg/kg CT group (H-CT), with six replicates per group and ten broilers per replicate. Sporulated coccidia oocysts on day 14 and Clostridium perfringens solution from days 19 to 21 were given to all broilers except the Control group through oral administration to establish the NE infection model. The results demonstrated that dietary supplementation with CT improved (p < 0.05) growth performance, intestinal morphology, and intestinal mucosal barrier function of broilers challenged with NE. CT supplementation decreased (p < 0.05) interleukin (IL)-1β, IL-6, type I interferon, interferon-γ, and tumor necrosis factor-α concentrations and increased (p < 0.05) IL-10 concentration in the jejunal mucosa. Furthermore, CT supplementation decreased (p < 0.05) Fe²⁺ concentration, malondialdehyde concentration, mitochondrial DNA level, and mitochondrial reactive oxygen species level in the jejunal mucosa. Broilers under NE challenge had upregulated (p < 0.05) jejunal protein expression of cGAS, STING, phospho-TANK-binding kinase 1, phospho-interferon regulatory factor 7, phospho-nuclear factor kappa B, ferroptosis suppressor protein 1, prostaglandin-endoperoxide synthase 2, acyl-CoA synthetase long-chain family member 4, WD repeat domain phosphoinositide-interacting protein 2, nuclear receptor co activator factor 4 and autophagy related protein 5 and downregulated (p < 0.05) glutathione peroxidase 4, ferritin heavy chain 1, ferritin light chain and ferroportin 1 compared with the Control group, while the supplementation of CT reversed these effects. In conclusion, CT improved intestinal inflammatory damage of broilers challenged with NE by inhibiting the cGAS-STING-ferroptosis pathway, which was more effective at a dose of 1000 mg/kg in this study. Full article

Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne pathogen causing low mortality but high morbidity in humans, with 4–14% cases exhibiting neurological complications. While the cyclic GMP-AMP synthase–stimulator of interferon genes (cGAS–STING) pathway is canonically associated with double-stranded DNA (dsDNA) detection, it has been shown to respond to RNA viruses and subsequently limit viral pathogenesis. Several viruses antagonize this signaling cascade, underscoring the importance that cGAS–STING plays in host immunity. Previous studies regarding single-stranded RNA viruses revealed that cGAS–STING limits viral replication in Old World alphavirus chikungunya virus infections, but little is known about New World alphaviruses such as VEEV. Here, we investigate the impact that STING activation has on VEEV infection as a potential prophylactic and therapeutic intervention. VEEV infection alone did not induce STING phosphorylation at Ser366, but interferon-stimulated genes (ISGs) were upregulated during the late phase of infection. Loss of STING through siRNA showed a partial dependency on STING for ISG transcription, suggesting that STING activation may occur through a noncanonical process. Priming of the STING pathway prior to infection was found to be critical in limiting viral replication; however, targeting STING activation post-infection abrogated the antiviral effects that dsDNA had on VEEV. VEEV suppressed STING phosphorylation in a multiplicity of infection (MOI)-dependent manner with the most robust pSTING (Ser366) inhibition observed at an MOI of 10. Collectively, our results suggest that VEEV antagonizes canonical STING activation. Full article

Rosmarinus officinalis L. is known for its drought tolerance; however, its growth is adversely affected by both mild and severe water stress. This study investigates the potential of rhizomicrobiome (RM) transplantation to strengthen water stress resilience. Three RMs derived from native plants—R. officinalis (RO), Pistacia lentiscus L. (PL), and Juniperus phoenicea L. (JP)—collected from a semi-arid Mediterranean garrigue were inoculated into R. officinalis subjected to severe drought stress for 30 days. Although RM transplantation did not result in an increase in biomass, it led to the accumulation of intermediates within the phenylpropanoid/coumarin pathway and significant source-specific alterations in other leaf metabolites. Specifically, PL-RM increased the abundance of lignans and stress signaling metabolites. JP-RM improved the root-to-shoot ratio and the sugar and sugar-alcohol accumulation in leaves. Both JP-RM and RO-RM treatments reduced the abundance of abscisic acid, cyclic GMP, and purine recycling pathways. Additionally, RO-RM decreased the abundance of fifteen defense-related metabolites, indicating a direct interference of the inoculum with the plant immune system. In conclusion, these findings suggest that targeted RM manipulation can be an effective strategy to modulate R. officinalis leaf metabolism. Full article

Cyclic GMP-AMP synthase (cGAS) functions as a DNA sensor in the cytoplasm, triggering immune responses, but it is also translocated to the nucleus, where it is kept catalytically inactive. It consists of an unstructured N-terminal domain of around 160 amino acids, and a larger C-terminal fold comprising the catalytic and DNA-binding domains. Subcellular localization of cGAS is thought to play a key role in its regulation. Here, we make use of heterologous expression in the eukaryotic model Saccharomyces cerevisiae to study cGAS localization in a neutral cellular environment. cGAS-eGFP was mostly found in aggregates at the endoplasmic reticulum–mitochondria encounter structure (ERMES) and juxtanuclear protein quality compartments (JUNQs), although some cells displayed an association between cGAS-eGFP and the plasma membrane. The N-terminus of cGAS fused to eGFP was unable to associate with the plasma membrane by itself, but its deletion dramatically promoted nuclear localization of cGAS-eGFP and decreased cytoplasmic aggregates. A mutant in the DNA-binding Zn-thumb motif of cGAS also showed a more prominent nuclear localization. Thus, both the N-terminal and C-terminal domains of cGAS seem to cooperate to prevent nuclear localization and to maintain cytoplasmic reservoirs of the protein. Heterologous cGAS expression in yeast is a valuable tool for modeling aspects of its subcellular localization and aggregative features. Full article

The yak represents a distinct domestic animal species that predominantly inhabits the Qinghai–Tibet Plateau and adjacent areas, possessing considerable value in both scientific and economic contexts. Compared to animals that mainly dwell on plains, such as cattle, the sperm maturation process in yak exhibits a certain degree of species specificity to adapt to their unique reproductive needs in high-altitude environments. Serving as the main storage site for functionally competent sperm, the cauda epididymis plays an integral role in mediating their post-testicular maturation. MiRNAs are vital regulatory molecules in the epididymis, influencing sperm maturation by modulating gene expression after transcription. To investigate the unique regulatory mechanisms of sperm maturation in yak, this study compared the miRNA expression profiles in the cauda epididymis of yak and cattle using high-throughput small RNA (sRNA) sequencing. The comparative analysis identified and characterized sRNA populations in the cauda epididymis of yak and cattle, revealing a similar length distribution that peaked at 22 nt and a predominance of known miRNAs. Notably, eight miRNAs were found to be highly expressed in both species. Furthermore, the first-nucleotide bias differed significantly between known and novel miRNAs within each species. A total of 31 differentially expressed (DE) miRNAs were identified, with 11 upregulated and 20 downregulated in yak compared to cattle. Among these, bta-miR-1298 exhibited the most significant upregulation, while bta-miR-2344 displayed the most pronounced downregulation. Bioinformatic analysis linked the predicted target genes of these miRNAs to numerous critical signaling pathways, including calcium signaling, the mitogen-activated protein kinase (MAPK) signaling pathway, the Ras-associated protein 1 (Rap1) signaling pathway, and the cyclic guanosine monophosphate-protein kinase G (cGMP-PKG) signaling pathway. Furthermore, eight significantly DE miRNAs, including bta-miR-2443, bta-miR-503-3p, bta-miR-6517, bta-miR-2440, bta-miR-2431-3p, bta-miR-2436-3p, bta-miR-6523a, and bta-miR-6775, were predicted to target genes involved in various aspects of sperm structural and functional maturation. These aspects include flagellum formation, sperm motility, chromatin remodeling, acrosome reaction, acrosome structure, sperm capacitation, chemotaxis, and nuclear chromatin condensation. Multiple miRNAs and their corresponding predicted target genes were analyzed by quantitative real-time PCR (qPCR), demonstrating an inverse correlation between miRNA expression and target gene levels. These findings reveal a distinct, species-specific miRNA signature in the yak cauda epididymis, which suggests a potential contribution to regulating the epididymal luminal environment and the process of sperm maturation. This study provides preliminary foundational data for elucidating the differences in sperm maturation mechanisms between yak and cattle, and offers potential novel targets for improving reproductive efficiency in plateau livestock. Full article