Circular RNAs (circRNAs) represent a distinct group of RNA molecules produced through back-splicing of precursor mRNAs. Their covalently closed structure, which lacks both a 5′ cap and a poly(A) tail, renders them highly resistant to exonucleolytic degradation and contributes to their remarkable intracellular stability. Although circRNAs were historically viewed as noncoding transcripts, accumulating evidence indicates that certain circRNAs can undergo translation under appropriate molecular contexts. Two major modes of noncanonical translation have been described so far: initiation mediated by internal ribosome entry sites (IRESs) and translation triggered by N6-methyladenosine (m6A) modification. Recent studies have revealed that, beyond their canonical classification as non-coding RNAs, circRNAs can give rise to functional peptides through cap-independent translational mechanisms. Accumulating evidence indicates that circRNA-encoded peptides participate in key biological processes during tumor initiation and progression by modulating tumor-associated signaling pathways and protein-protein interaction networks. Functionally, these peptides may promote tumor cell proliferation, migration, invasion, and epithelial-mesenchymal transition, while others exert tumor-suppressive effects by inhibiting oncogenic signaling pathways or interfering with critical protein interactions. Their dual and context-dependent functions highlight the complexity of circRNA-mediated regulation and suggest that these translation products participate in multiple layers of tumor initiation and progression. In this review, we synthesize current knowledge regarding the molecular mechanisms that enable circRNAs to be translated, with particular attention to IRES-driven initiation, m6A-dependent regulation, ribosome accessibility, and the structural determinants required for translation competence. We further summarize well-characterized circRNA-encoded peptides and discuss how they influence tumor-associated signaling networks. In addition, we examine the potential translational applications of these peptides, including their value as diagnostic indicators, prognostic markers, or therapeutic entry points. Their inherent sequence stability, relative expression specificity, and detectability in clinical specimens make circRNA-derived peptides promising candidates for future biomarker and therapeutic development. Overall, circRNA translation research is reshaping our understanding of RNA function and offers new perspectives for studying tumor biology. We propose that expanding investigations into circRNA-encoded peptides will not only improve the mechanistic resolution of cancer research but may also pave the way for innovative strategies in precision oncology, including RNA-based therapeutics and peptide-targeting interventions.

Circular RNAs (circRNAs) represent a distinct group of RNA molecules produced through back-splicing of precursor mRNAs. Their covalently closed structure, which lacks both a 5′ cap and a poly(A) tail, renders them highly resistant to exonucleolytic degradation and contributes to their remarkable intracellular stability. Although circRNAs were historically viewed as noncoding transcripts, accumulating evidence indicates that certain circRNAs can undergo translation under appropriate molecular contexts. Two major modes of noncanonical translation have been described so far: initiation mediated by internal ribosome entry sites (IRESs) and translation triggered by N6-methyladenosine (m6A) modification. Recent studies have revealed that, beyond their canonical classification as non-coding RNAs, circRNAs can give rise to functional peptides through cap-independent translational mechanisms. Accumulating evidence indicates that circRNA-encoded peptides participate in key biological processes during tumor initiation and progression by modulating tumor-associated signaling pathways and protein-protein interaction networks. Functionally, these peptides may promote tumor cell proliferation, migration, invasion, and epithelial-mesenchymal transition, while others exert tumor-suppressive effects by inhibiting oncogenic signaling pathways or interfering with critical protein interactions. Their dual and context-dependent functions highlight the complexity of circRNA-mediated regulation and suggest that these translation products participate in multiple layers of tumor initiation and progression. In this review, we synthesize current knowledge regarding the molecular mechanisms that enable circRNAs to be translated, with particular attention to IRES-driven initiation, m6A-dependent regulation, ribosome accessibility, and the structural determinants required for translation competence. We further summarize well-characterized circRNA-encoded peptides and discuss how they influence tumor-associated signaling networks. In addition, we examine the potential translational applications of these peptides, including their value as diagnostic indicators, prognostic markers, or therapeutic entry points. Their inherent sequence stability, relative expression specificity, and detectability in clinical specimens make circRNA-derived peptides promising candidates for future biomarker and therapeutic development. Overall, circRNA translation research is reshaping our understanding of RNA function and offers new perspectives for studying tumor biology. We propose that expanding investigations into circRNA-encoded peptides will not only improve the mechanistic resolution of cancer research but may also pave the way for innovative strategies in precision oncology, including RNA-based therapeutics and peptide-targeting interventions.

ObjectiveMitochondria are not only the central organelles responsible for cellular energy metabolism but also play essential roles in regulating cell cycle progression and cytoskeletal dynamics. In recent years, accumulating evidence has demonstrated that mitochondrial homeostasis is closely associated with mitotic progression and cytokinesis. Schizosaccharomyces pombe serves as a classical and well-established model organism. Because its cell cycle regulatory mechanisms are highly conserved throughout evolution, its genetic background is clearly defined, and experimental manipulation is efficient and convenient, it has been extensively applied in studies of cell growth, division, and reproductive mechanisms. The SPBC1604.04 gene encodes a previously uncharacterized mitochondrial carrier protein in Schizosaccharomyces pombe. This gene is located on chromosome II and spans 1 018 base pairs in length. It encodes a protein consisting of 238 amino acids with a predicted molecular mass of approximately 31.03 ku. Bioinformatic analysis predicts that this protein is responsible for the transport of thiamine pyrophosphate (TPP) into mitochondria. However, the effects of SPBC1604.04 gene deletion on mitotic cell dynamics under different temperature conditions have not been fully elucidated. MethodsThe SPBC1604.04 deletion strain of Schizosaccharomyces pombe was used as the experimental model. Fluorescent protein markers were constructed in the deletion background to label mitochondria, microtubules, actin, myosin, the nuclear envelope, and chromosomes. Live-cell imaging was performed using a TCS-SP8 laser scanning confocal microscope under normal temperature conditions (25℃) and heat stress conditions (37℃). Time-lapse microscopy was applied to dynamically monitor mitochondrial morphology and distribution, spindle assembly and elongation, chromosome segregation, as well as the formation and constriction of the actomyosin ring during cytokinesis. ImageJ software was used for quantitative measurements, including microtubule length during mitosis, spindle length at different mitotic stages, mitochondrial fluorescence intensity as an indicator of mitochondrial content, actomyosin ring length, nuclear envelope area, and chromosome segregation timing. Statistical analyses were conducted to compare phenotypic differences between the wild-type and SPBC1604.04 deletion strains at both temperature conditions. Through these analyses, we systematically investigated the impact of SPBC1604.04 deletion on mitotic cell dynamics in fission yeast under both normal physiological conditions and temperature stress. ResultsAt 25℃, compared with wild-type cells, the SPBC1604.04Δ strain exhibited a pronounced tendency toward mitochondrial fragmentation, accompanied by abnormal mitochondrial content and a significant reduction in mitochondrial fluorescence intensity. These observations suggest impaired mitochondrial homeostasis under normal growth conditions. In addition, the constriction time of actomyosin ring during cytokinesis was markedly prolonged, indicating that deletion of SPBC1604.04 affects the dynamics of the contractile machinery. However, no obvious defects were observed in spindle assembly, spindle elongation, or chromosome segregation. Under heat stress at 37℃, mitochondrial morphology in the SPBC1604.04Δ strain showed a tendency to recover toward a continuous tubular network structure. Mitochondrial content was restored, fluorescence intensity increased, and the constriction time of the actomyosin ring returned to levels comparable to those of wild-type cells. These results indicate that the mitotic defects observed at normal temperature are partially or fully alleviated under heat stress conditions. ConclusionThis study demonstrates that deletion of the SPBC1604.04 gene leads to abnormal mitochondrial content in Schizosaccharomyces pombe. The mitochondrial carrier protein SPBC1604.04 participates in regulating actomyosin ring constriction during mitosis but does not appear to be directly involved in the regulation of spindle dynamics or chromosome segregation. Our findings provide key experimental evidence for understanding the functional link between the SPBC1604.04 gene, mitochondrial homeostasis, and mitotic regulation.

ObjectiveMitochondria are not only the central organelles responsible for cellular energy metabolism but also play essential roles in regulating cell cycle progression and cytoskeletal dynamics. In recent years, accumulating evidence has demonstrated that mitochondrial homeostasis is closely associated with mitotic progression and cytokinesis. Schizosaccharomyces pombe serves as a classical and well-established model organism. Because its cell cycle regulatory mechanisms are highly conserved throughout evolution, its genetic background is clearly defined, and experimental manipulation is efficient and convenient, it has been extensively applied in studies of cell growth, division, and reproductive mechanisms. The SPBC1604.04 gene encodes a previously uncharacterized mitochondrial carrier protein in Schizosaccharomyces pombe. This gene is located on chromosome II and spans 1 018 base pairs in length. It encodes a protein consisting of 238 amino acids with a predicted molecular mass of approximately 31.03 ku. Bioinformatic analysis predicts that this protein is responsible for the transport of thiamine pyrophosphate (TPP) into mitochondria. However, the effects of SPBC1604.04 gene deletion on mitotic cell dynamics under different temperature conditions have not been fully elucidated. MethodsThe SPBC1604.04 deletion strain of Schizosaccharomyces pombe was used as the experimental model. Fluorescent protein markers were constructed in the deletion background to label mitochondria, microtubules, actin, myosin, the nuclear envelope, and chromosomes. Live-cell imaging was performed using a TCS-SP8 laser scanning confocal microscope under normal temperature conditions (25℃) and heat stress conditions (37℃). Time-lapse microscopy was applied to dynamically monitor mitochondrial morphology and distribution, spindle assembly and elongation, chromosome segregation, as well as the formation and constriction of the actomyosin ring during cytokinesis. ImageJ software was used for quantitative measurements, including microtubule length during mitosis, spindle length at different mitotic stages, mitochondrial fluorescence intensity as an indicator of mitochondrial content, actomyosin ring length, nuclear envelope area, and chromosome segregation timing. Statistical analyses were conducted to compare phenotypic differences between the wild-type and SPBC1604.04 deletion strains at both temperature conditions. Through these analyses, we systematically investigated the impact of SPBC1604.04 deletion on mitotic cell dynamics in fission yeast under both normal physiological conditions and temperature stress. ResultsAt 25℃, compared with wild-type cells, the SPBC1604.04Δ strain exhibited a pronounced tendency toward mitochondrial fragmentation, accompanied by abnormal mitochondrial content and a significant reduction in mitochondrial fluorescence intensity. These observations suggest impaired mitochondrial homeostasis under normal growth conditions. In addition, the constriction time of actomyosin ring during cytokinesis was markedly prolonged, indicating that deletion of SPBC1604.04 affects the dynamics of the contractile machinery. However, no obvious defects were observed in spindle assembly, spindle elongation, or chromosome segregation. Under heat stress at 37℃, mitochondrial morphology in the SPBC1604.04Δ strain showed a tendency to recover toward a continuous tubular network structure. Mitochondrial content was restored, fluorescence intensity increased, and the constriction time of the actomyosin ring returned to levels comparable to those of wild-type cells. These results indicate that the mitotic defects observed at normal temperature are partially or fully alleviated under heat stress conditions. ConclusionThis study demonstrates that deletion of the SPBC1604.04 gene leads to abnormal mitochondrial content in Schizosaccharomyces pombe. The mitochondrial carrier protein SPBC1604.04 participates in regulating actomyosin ring constriction during mitosis but does not appear to be directly involved in the regulation of spindle dynamics or chromosome segregation. Our findings provide key experimental evidence for understanding the functional link between the SPBC1604.04 gene, mitochondrial homeostasis, and mitotic regulation.

Background: High-mobility group box protein 1 (HMGB1) is a chromatin-binding protein involved in arthritis, ischemia, sepsis, atherosclerosis, neurodegenerative disorders, meningitis, and cancer. HMGB1 exhibits dual roles in cancer, acting as either a tumor suppressor or oncoprotein depending on context. Objective: This research aimed to elucidate HMGB1’s functional significance in cutaneous squamous cell carcinoma (cSCC). Methods: We overexpressed HMGB1 in cSCC cell lines using recombinant adenovirus and examined its effects on cell proliferation, colony formation, and cell migration. Results: Immunohistochemical analysis revealed elevated HMGB1 expression levels in cSCC tissue relative to normal epidermis. To assess the influence of HMGB1, we employed recombinant adenoviruses expressing HMGB1 to transduce SCC cell lines (SCC12 and SCC13). Enhanced HMGB1 expression significantly promoted cellular proliferation and colony formation capacity.Notably, HMGB1 overexpression elevated the levels of proliferation regulators, including P63, SOX2, CDK4 and CDK6. Furthermore, HMGB1 overexpression substantially enhanced tumor invasiveness, accompanied by upregulation of epithelial-mesenchymal transition (EMT) biomarkers. Mechanistically, overexpression of HMGB1 enhanced transforming growth factor-β signaling by increasing phosphorylation of SMAD2/3, the key mediators of EMT. Conclusion These data imply that HMGB1 acts as a tumor-promoting factor in cSCC.

Objective This study reports on the obligatory parasitism of water mites Arrenurus sp. on Anopheles messeae at the Manzhouli Port, Inner Mongolia, China. Methods Duing July 2024, a survey on the mosquito diversity was conducted at the Manzhouli Port. Captured mosquitoes and their ectoparasites were identified to species level. Results A total of 1840 adult mosquitoes were collected, representing species from three genera: Culex(Cx. modestus, Cx. pipiens pallens), Aedes(Ae. dorsalis, Ae. flavidorsalis, Ae. flavescens), and Anopheles (An. messeae). Among all the mosqutioes specimens,3 out of 150 captured An. messeae were found to carry ectoparasitic mites, with number of 2,4,27 mites separately. Morphological and molecular identification reached the same result as water mites(Hydrachnidiae, Hydracrina). COI gene sequence showed 94% similarity with the closest species Arrenurus truncatellus. Conlusions Literature review suggests water mites are host-specific parasitism of mosquito species and herein with the first record of Arrenurus sp. parasiting on An. Messeae in the most high-latitude region globally.

Objective To investigate the risk factors for ICU-acquired weakness (ICU-AW) in patients with sepsis, and to construct a nomogram prediction model. Methods A total of 360 patients with sepsis admitted from January 2020 to December 2025 were enrolled as study subjects. The risk factors for ICU-AW were identified by logistic regression analysis. A nomogram prediction model was constructed, and the model was validated. Results Multivariate logistic regression analysis indicated that age, APACHE II score, duration of mechanical ventilation, duration of immobilization, duration of sedation, and NLR were risk factors for the occurrence of ICU-AW (P<0.05), while ALB was a protective factor (P<0.05). A nomogram model was constructed based on these seven variables. After validation via Bootstrap resampling, ROC curve showed an AUC of 0.949 (0.929–0.969) and a corrected AUC of 0.942 (0.940–0.948), indicating good discrimination degree of the model. Hosmer-Lemeshow test for calibration curve revealed a chi-square value of 10.188 (P=0.252), suggesting that the predicted value of fitting was generally consistent with the actual value. Decision curve analysis demonstrated that when the threshold was in the range of 0.05–0.9, the model had a good net benefit. Conclusion The nomogram prediction model for sepsis ICU-AW based on seven indicators including age, APACHE II score, NLR, ALB, and the durations of mechanical ventilation, immobilization, and sedation exhibits good predictive efficiency and stability. This nomogram prediction model is helpful for the clinical rapid screening of ICU-AW high-risk groups in patients with sepsis, and meets clinical needs for early warning and precise prevention and control.

In this experiment, self-assembled nanoparticles(SANs) were prepared by the pH-driven method, and Her-HCP SAN was constructed by using herpetrione(Her) and Herpetospermum caudigerum polysaccharides(HCPs). The average particle size and polydispersity index(PDI) were used as evaluation indexes for process optimization, and the quality of the final formulation was evaluated in terms of particle size, PDI, Zeta potential, and microstructure. The proposed Her-HCP SAN showed a spheroid structure and uniform morphology, with an average particle size of(244.58±16.84) nm, a PDI of 0.147 1±0.014 8, and a Zeta potential of(-38.52±2.11) mV. Her-HCP SAN significantly increased the saturation solubility of Her by 2.69 times, with a cumulative release of 90.18% within eight hours. The results of in vivo unidirectional intestinal perfusion reveal that Her active pharmaceutical ingredient(API) is most effectively absorbed in the jejunum, where both K_a and P_(app) are significantly higher compared to the ileum(P<0.001). However, the addition of HCP leads to a significant reduction in the P_(app) of Her in the jejunum(P<0.05). Furthermore, the formation of the Her-HCP SAN results in a notably lower P_(app) in the jejunum compared to Her API alone(P<0.001), while both K_a and P_(app) in the ileum are significantly increased(P<0.001, P<0.05). The absorption of Her-HCP SAN at different concentrations in the ileum shows no significant differences, and the pH has no significant effect on the absorption of Her-HCP SAN in the ileum. The addition of the transporter protein inhibitors(indomethacin and rifampicin) significantly increases the absorption parameters K_a and P_(app) of Her-HCP SAN in the ileum(P<0.05,P<0.01), whereas the addition of verapamil has no significant effect on the intestinal absorption parameters of Her-HCP SAN, suggesting that Her may be a substrate for multidrug resistance-associated protein 2 and breast cancer resistance proteins but not a substrate of P-glycoprotein.
Nanoparticles/metabolism* ; Polysaccharides/pharmacokinetics* ; Intestinal Absorption/drug effects* ; Animals ; Rats ; Particle Size ; Drugs, Chinese Herbal/pharmacokinetics* ; Male ; Rats, Sprague-Dawley ; Drug Carriers/chemistry* ; Drug Compounding ; Cucurbitaceae/chemistry*

This study aims to explore the effects and mechanisms of 4'-O-methylbavachalcone(MeBavaC), an active compound from Psoraleae Fructus, in regulating white matter neuroinflammation to improve vascular cognitive impairment. Male Sprague-Dawley(SD) rats were randomly divided into four groups: sham group, model group, high-dose MeBavaC group(14 mg·kg~(-1)), and low-dose MeBavaC group(7 mg·kg~(-1)). The rat model of chronic cerebral hypoperfusion(CCH) was established using bilateral common carotid artery occlusion. The Morris water maze test was performed to evaluate the learning and memory abilities of the rats. Luxol fast blue staining, Nissl staining, immunofluorescence, immunohistochemistry, and transmission electron microscopy were utilized to observe the morphology and ultrastructure of the white matter myelin sheaths, axon integrity, the morphology and number of hippocampal neurons, and the loss and activation of glial cells in the white matter. Transcriptome analysis was performed to explore the potential mechanisms of white matter injury induced by CCH. Western blot and quantitative real-time polymerase chain reaction(qRT-PCR) assays were conducted to measure the expression levels of NOD-like receptor protein 3(NLRP3), absent in melanoma 2(AIM2), gasdermin D(GSDMD), cysteinyl aspartate-specific proteinase-1(caspase-1), interleukin-18(IL-18), interleukin-1β(IL-1β), erythropoietin(EPO), nuclear factor erythroid 2-related factor 2(Nrf2), and heme oxygenase-1(HO-1) in the white matter of rats. The results showed that compared with the model group, MeBavaC significantly improved the learning and memory abilities of rats with CCH, improved the damage of white matter myelin sheath, maintained axonal integrity, reduced the loss of hippocampal neurons and oligodendrocytes in the white matter, inhibited the activation of microglia and the proliferation of astrocytes in the white matter, and suppressed the NLRP3/AIM2/caspase-1/GSDMD pathway. The expression levels of inflammatory cytokines IL-1β and IL-18 were significantly reduced, while EPO expression and the expression of Nrf2/HO-1 antioxidant pathway were notably elevated. In conclusion, MeBavaC can alleviate cognitive impairment in rats with CCH and suppress neuroinflammation in cerebral white matter. The mechanism of action may involve activation of EPO activity, promotion of endogenous antioxidant pathways, and inhibition of neuroinflammation in the white matter. This study suggests that MeBavaC exhibits antioxidant and anti-neuroinflammatory effects, showing potential application in improving cognitive dysfunction.
Animals ; Male ; Rats, Sprague-Dawley ; NF-E2-Related Factor 2/immunology* ; Rats ; Chalcones/administration & dosage* ; Cognitive Dysfunction/metabolism* ; Signal Transduction/drug effects* ; Neuroinflammatory Diseases/drug therapy* ; Heme Oxygenase-1/metabolism* ; Humans ; Heme Oxygenase (Decyclizing)/genetics*