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.

This study aims to investigate the molecular mechanism by which naringin alleviates cerebral ischemia/reperfusion(CI/R) injury through DRP1/LRRK2/MCU signaling axis. A total of 60 SD rats were randomly divided into the sham group, the model group, the sodium Danshensu group, and low-, medium-, and high-dose(50, 100, and 200 mg·kg~(-1)) naringin groups, with 10 rats in each group. Except for the sham group, a transient middle cerebral artery occlusion/reperfusion(tMCAO/R) model was established in SD rats using the suture method. Longa 5-point scale was used to assess neurological deficits. 2,3,5-Triphenyl tetrazolium chloride(TTC) staining was used to detect the volume percentage of cerebral infarction in rats. Hematoxylin-eosin(HE) staining and Nissl staining were employed to assess neuronal structural alterations and the number of Nissl bodies in cortex, respectively. Western blot was used to determine the protein expression levels of B-cell lymphoma-2 gene(Bcl-2), Bcl-2-associated X protein(Bax), cleaved cysteine-aspartate protease-3(cleaved caspase-3), mitochondrial calcium uniporter(MCU), microtubule-associated protein 1 light chain 3(LC3), and P62. Mitochondrial structure and autophagy in cortical neurons were observed by transmission electron microscopy. Immunofluorescence assay was used to quantify the fluorescence intensities of MCU and mitochondrial calcium ion, as well as the co-localization of dynamin-related protein 1(DRP1) with leucine-rich repeat kinase 2(LRRK2) and translocase of outer mitochondrial membrane 20(TOMM20) with LC3 in cortical mitochondria. The results showed that compared with the model group, naringin significantly decreased the volume percentage of cerebral infarction and neurological deficit score in tMCAO/R rats, alleviated the structural damage and Nissl body loss of cortical neurons in tMCAO/R rats, inhibited autophagosomes in cortical neurons, and increased the average diameter of cortical mitochondria. The Western blot results showed that compared to the sham group, the model group exhibited increased levels of cleaved caspase-3, Bax, MCU, and the LC3Ⅱ/LC3Ⅰ ratio in the cortex and reduced protein levels of Bcl-2 and P62. However, naringin down-regulated the protein expression of cleaved caspase-3, Bax, MCU and the ratio of LC3Ⅱ/LC3Ⅰ ratio and up-regulated the expression of Bcl-2 and P62 proteins in cortical area. In addition, immunofluorescence analysis showed that compared with the model group, naringin and positive drug treatments significantly decreased the fluorescence intensities of MCU and mitochondrial calcium ion. Meanwhile, the co-localization of DRP1 with LRRK2 and TOMM20 with LC3 in cortical mitochondria was also decreased significantly after the intervention. These findings suggest that naringin can alleviate cortical neuronal damage in tMCAO/R rats by inhibiting DRP1/LRRK2/MCU-mediated mitochondrial fragmentation and the resultant excessive mitophagy.
Animals ; Rats, Sprague-Dawley ; Reperfusion Injury/genetics* ; Flavanones/administration & dosage* ; Rats ; Dynamins/genetics* ; Male ; Brain Ischemia/genetics* ; Protein Serine-Threonine Kinases/genetics* ; Signal Transduction/drug effects* ; Humans ; Drugs, Chinese Herbal/administration & dosage*

The chemical components of Carthami Flos were investigated by using macroporous resin, silica gel column chromatography, reversed-phase octadecylsilane(ODS) column chromatography, Sephadex LH-20, and semi-preparative high-performance liquid chromatography(HPLC). The planar structures of the compounds were established based on their physicochemical properties and ultraviolet-visible(UV-Vis), infrared(IR), high-resolution electrospray ionization mass spectrometry(HR-ESI-MS), and nuclear magnetic resonance(NMR) spectroscopic technology. The absolute configurations were determined by comparing the calculated and experimental electronic circular dichroism(ECD). Six flavonoid C-glycosides were isolated from the 30% ethanol elution fraction of macroporous resin obtained from the 95% ethanol extract of Carthami Flos, and identified as saffloquinoside F(1), 5-hydroxysaffloneoside(2), iso-5-hydroxysaffloneoside(3), isosafflomin C(4), safflomin C(5), and vicenin 2(6). Among these, the compounds 1 to 3 were new chalcone C-glycosides. The compounds 1, 2, 4, and 5 could significantly increase the viability of H9c2 cardiomyocytes damaged by oxygen-glucose deprivation/reoxygenation(OGD/R) at a concentration of 50 μmol·L~(-1), showing their good cardioprotective activity.
Glycosides/pharmacology* ; Flowers/chemistry* ; Drugs, Chinese Herbal/pharmacology* ; Carthamus tinctorius/chemistry* ; Chalcones/pharmacology* ; Animals

OBJECTIVE: To explore early curative effect of upper joint capsule reconstruction combined with biceps tendon transposition in treating irreparable rotator cuff tears. METHODS: From October 2019 to March 2021, 16 patients with irreparable rotator cuff tear were underwent arthroscopic autogenous semitendinosus tendon transplantation for upper articular capsule reconstruction combined with biceps tendon transposition, included 12 males and 4 females, aged from 53 to 72 years old with an average of (62.13±5.35) years old; 3 patients on the left side and 13 patients on the right side. All patients had preoperatively limited joint mobility, resting pain, and mobility pain, and had a history of failure to respond to conservative treatment for more than 8 months. The duration of preoperative symptoms ranged from 45 to 144 months with an average of (85.25±32.08) months. Visual analogue scale (VAS) of shoulder pain, University of California Los Angeles (UCLA) score, Constant-Murley score, active and passive motion of shoulder joint were compared before operation and 2 years after operation, complications were recorded. RESULTS: All 16 patients were followed up for 21 to 32 months with an average of (24.25±3.57) months. There were no complications such as incision infection, vascular and nerve injury, retear occurred. VAS, UCLA and Constant-Murley scores were improved from (5.75±1.18), (11.88±3.38) and (33.38±9.34) before operation to (1.13±0.89), (32.56±2.71), (89.06±6.25) at 2 years after operation (P<0.05). Anterior flexion, abduction, lateral external rotation and lateral internal rotation of shoulder joint were improved from (79.75±21.36) °, (62.06±10.49) °, (19.19±5.41) °, (3.04±0.21) °, respectively to (156.94±13.18) °, (116.19±12.59) °, (42.63±6.07) °, (8.16±0.64) ° at 2 years after operation. Anterior flexion, abduction, lateral lateral rotation and lateral internal rotation of shoulder joint were improved from (116.28±21.47) °, (107.12±9.67) °, (27.62±4.70) °, (4.21±0.41) °, respectively to (165.28±7.15) °, (153.34±4.69) °, (52.46±4.46) °, (9.68±0.68) ° at 2 years after operation, and the difference was statistically significant (P<0.05). CONCLUSION Arthroscopic autograft of semitendinosus tendon combined with transposition of biceps tendon could achieve satisfactory early clinical results in treating patients with irreparable rotator cuff tear, which is a reliable and effective surgical method.
Humans ; Male ; Female ; Middle Aged ; Aged ; Arthroscopy/methods* ; Rotator Cuff Injuries/physiopathology* ; Plastic Surgery Procedures/methods* ; Range of Motion, Articular ; Shoulder Joint/surgery* ; Tendon Transfer

OBJECTIVE: To explore clinical effect of autologous osteochondral transplantation (AOT) in the treatment of recurrent anterior dislocation of the shoulder joint with glenoid cartilage defect in rabbits by establishing a model of recurrent anterior dislocation of the shoulder joint with < 20% glenoid cartilage defect in rabbits. METHODS: Twenty-four male New Zealand white rabbits, aged 6-month-old, weighed (2.69±0.17) kg were selected. The labrum of shoulder joint of rabbits was artificially destroyed to establish a model of recurrent anterior dislocation of shoulder joint with cartilage defect. They were divided into AOT surgery group and simple suture group, with 12 rabbits in each group. AOT group were underwent AOT surgery, while simple suture group was treated with simple Bankart suture for recurrent shoulder joint dislocation. At 6 and 12 weeks after operation, 6 rabbits between two groups were sacrificed for sampling. The dietary conditions, activity conditions, mental states of rabbits and healing conditions of grafts in the specimens were observed and compared between two groups. HE staining was used to observe cell creep, cell morphology, inflammatory cell infiltration, fibrochondrocytes and their arrangement. Masson staining was used to observe the formation and arrangement of collagen fibers; Safrane-green staining was used to observe the regeneration of articular cartilage, subchondral bone and bone tissue. Bone mineral density (BMD), bone volume (BV) and trabecular thickness (Tb.Th) between two groups were measured by Micro-CT to evaluate the remodeling of shoulder glenoid bone defects by autologous osteochondral cartilage. RESULTS: After different surgical interventions were carried out in both groups of rabbits, at 6 weeks after the operation, the abduction, extension, internal rotation and external rotation of the shoulder joint on the operated side showed limited range of motion compared with the contralateral side, while adduction and forward flexion showed no obvious abnormalities compared with the contralateral side. At 12 weeks after operation, the range motion of tshoulder joints in both groups of rabbits had returned to the state before modeling. The effects of HE staining, Masson staining and safrane-green staining at 12 weeks after operation in both groups were stronger than the staining results at 6 weeks after operation. Moreover, the results of HE staining, Masson staining and safranin fixation green staining in AOT group at 6 and 12 weeks after operation were all higher than those in simple suture group. Micro-CT scan results at 6 and 12 weeks after operation showed that BMD (0.427±0.014), (0.466±0.032) g·cm-3, BV(116.171±3.527), (159.327±3.500) mm3, and Tb.Th (0.230±0.006), (0.285±0.009) mm in AOT group, which were higher than those of simple suture group in BMD(0.358±0.011), (0.384±0.096) g·cm-3, BV(72.657±3.903), (118.713±3.860) mm3, and Tb.Th(0.204±0.009), (0.243±0.007) mm;and the differences were statistically significant (P<0.05). CONCLUSION AOT procedure could effectively promote osteogenesis and fibrocartilage regeneration in the cartilage defect area of the shoulder glenoid <20%, which is conducive to reshaping the structure of the shoulder glenoid.
Animals ; Rabbits ; Male ; Transplantation, Autologous ; Cartilage, Articular/injuries* ; Shoulder Dislocation/physiopathology* ; Bone Transplantation ; Shoulder Joint/surgery*

OBJECTIVE: To evaluate the effects of posterior cruciate ligament(PCL) resection on soft tissue elasticity and knee stability in total knee arthroplasty(TKA). METHODS: Six adult cadaveric knee specimens (involving 10 knees) were included in the study. With the assistance of the robotic system(TiRobot Recon, TINAVI, Beijing), total knee arthroplasty (TKA) was performed sequentially using cruciate retaining (CR) prostheses and posterior stabilizing (PS) prostheses. Between the two surgical procedures, the femoral and tibial osteotomy surfaces were not altered;only the posterior cruciate ligament (PCL) was resected and the intercondylar fossa was treated. After installing the femoral trial component, a soft tissue balance solver was used to apply tension ranging from 30 N to 90 N in 5 N increments at 0°, 10°, and 90° of knee flexion. Meanwhile, the medial and lateral joint gaps were measured synchronously. Based on the tension-gap coupling data, the equivalent elastic coefficients of the medial and lateral soft tissue sleeves at different knee flexion angles, as well as the range of the joint line convergence angle (JLCA) under fixed varus-valgus stress, were calculated. Additionally, the gap balance status under 80 N of tension was analyzed. Self-control comparisons of each indicator were conducted before and after PCL resection to analyze the change patterns. RESULTS: After PCL resection, in the fully extended position (knee flexion 0°). The medial equivalent elastic coefficient was 32.2 (25.7, 63.3) N·mm^-1 for the CR prosthesis and 27.7 (22.0, 51.9) N·mm^-1 for the PS prosthesis, and the statistically significant difference (P=0.013). The range of JLCA was 0.41°(0.26, 0.55)° for the CR prosthesis, which was smaller than 0.75° (0.40, 0.98)° for the PS prosthesis, and the difference was statistically significant(P=0.041). At 90° of knee flexion, the medial joint gap was 10.7(10.1, 11.7) mm for the CR prosthesis, which was smaller than 12.1(10.9, 15.1) mm for the PS prosthesis, with a statistically significant difference(P=0.011). No statistically significant differences were observed in other joint gaps. CONCLUSION PCL resection reduces the rigidity of the medial soft tissues in the fully extended knee and increases the medial joint gap in the flexed position, thereby affecting knee stability and balance. This finding suggests that PS and CR prostheses may require different morphological designs, and there should be differences in indications and osteotomy strategies between CR-TKA and PS-TKA. CR-TKA is more suitable for patients with preoperative medial soft tissue laxity.
Humans ; Posterior Cruciate Ligament/physiopathology* ; Knee Joint/physiopathology* ; Arthroplasty, Replacement, Knee ; Elasticity ; Male ; Female ; Middle Aged ; Aged ; Biomechanical Phenomena ; Adult

The prelimbic cortex (PL) plays a critical role in processing both the sensory and affective components of pain. However, the underlying molecular mechanisms remain poorly understood. In this study, we observed a reduction in hyperpolarization-activated cation current (I_h) in layer V pyramidal neurons of the contralateral PL in a mouse model of spared nerve injury (SNI). The expression of hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) channels was also decreased in the contralateral PL. Conversely, microinjection of fisetin, a partial agonist of HCN2, produced both analgesic and anxiolytic effects. Additionally, we found that cyclin-dependent kinase 5 (CDK5) was activated in the contralateral PL, where it formed a complex with HCN2 and phosphorylated its C-terminus. Knockdown of CDK5 restored HCN2 expression and alleviated both pain hypersensitivity and anxiety-like behaviors. Collectively, these results indicate that CDK5-mediated dysfunction of HCN2 in the PL underlies nerve injury-induced mechanical hypersensitivity and anxiety.
Animals ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels/metabolism* ; Hyperalgesia/metabolism* ; Cyclin-Dependent Kinase 5/metabolism* ; Neuralgia/metabolism* ; Male ; Anxiety/metabolism* ; Mice ; Potassium Channels/metabolism* ; Mice, Inbred C57BL ; Disease Models, Animal ; Pyramidal Cells/metabolism*

Objective To investigate the effect of long non-coding RNA(lncRNA)potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1(KCNQ1OT1)on oxidative glucose deprivation/reoxygenation(OGD/R)-induced microglia injury through regulating the miR-145-5p/Rho-associated coiled-coil forming protein kinase 1(ROCK1)axis.Methods Microglia N9 were divided into the control group(normal culture),the OGD/R group(OGD/R-induced injury),the sh-NC group(transfected with sh-NC after OGD/R-induced injury),the sh-KCNQ1OT1 group(transfected with sh-KCNQ1OT1 after OGD/R-induced injury),the sh-KCNQ1OT1+inhibitor NC group(co-transfected with sh-KCNQ1OT1 and inhibitor NC after OGD/R-induced injury),and the sh-KCNQ1OT1+miR-145-5p inhibitor group(co-transfected with sh-KCNQ1OT1 and miR-145-5p inhibitor after OGD/R-induced injury).RT-qPCR was applied to detect the expression of lncRNA KCNQ1OT1,miR-145-5p,and ROCK1 mRNA in cells.The expression of ROCK1 protein was detected by Western blot.CCK-8 was applied to detect the cell proliferation.Flow cytometry was applied to detect cell apoptosis.ELISA was applied to detect the levels of interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),and interleukin-6(IL-6)in cells.The action sites of miR-145-5p with lncRNA KCNQ1OT1 and ROCK1 were predicted by bioinformatics website,and their targeting relationships were verified by dual-luciferase reporter assay.Results Compared with the control group,the expression of lncRNA KCNQ1OT1,the expression of ROCK1 mRNA and protein,the apoptosis rate,and the levels of IL-6,TNF-α,and IL-1β in cells were all increased,and the level of miR-145-5p and cell survival rate were all decreased in the OGD/R group(P<0.05).Compared with the OGD/R group and the sh-NC group,the expression of lncRNA KCNQ1OT1,the expression of ROCK1 mRNA and protein,the apoptosis rate,and the levels of IL-6,TNF-α,and IL-1β in cells were all decreased,and the level of miR-145-5p and cell survival rate were all increased in the sh-KCNQ1OT1 group,with significant differences(P<0.05).Compared with the sh-KCNQ1OT1+inhibitor NC group,the expression of ROCK1 mRNA and protein,the apoptosis rate,and the levels of IL-6,TNF-α,and IL-1β in cells were all increased,and the expression of miR-145-5p and cell survival rate were all decreased in the sh-KCNQ1OT1+miR-145-5p inhibitor group,with significant differences(P<0.05).Bioinformatics website showed that miR-145-5p had targeted action sites with lncRNA KCNQ1OT1 and ROCK1,and dual-luciferase reporter assay confirmed that miR-145-5p had targeting relationships with lncRNA KCNQ1OT1 and ROCK1(P<0.05).Conclusion Silencing lncRNA KCNQ1OT1 can alleviate OGD/R-induced microglia injury via upregulating the expression of miR-145-5p and targeting the down-regulation of ROCK1 expression.

Medical therapy and surgical intervention are the two primary approaches for treating myocardial bridge.However,there remains controversy regarding the use of coronary artery bypass grafting(CABG)and myocardial bridge unroofing.Here,we report a case of myocardial infarction following CABG in a patient with a myocardial bridge.The patient was admitted to Lanzhou First Peopie's Hospital with persistent chest pain,chest tightness,and shortness of breath lasting 2 hours.Physical examination revealed no significant abnormalities.Electrocardiography(ECG)indicated extensive anterior wall myocardial infarction.Laboratory findings showed myoglobin levels of 140.1 ng/ml and troponin Ⅰ levels of 2.59 ng/ml,with no other significant abnormalities.The initial diagnosis was acute extensive anterior wall myocardial infarction.Emergency coronary angiography revealed a myocardial bridge in the mid-segment of the left anterior descending artery(LAD).Emergency CABG using the left internal mammary artery to the LAD was performed,leading to symptomatic improvement,and the patient was discharged in stable condition.However,the patient experienced a recurrent myocardial infarction seven years post-surgery and received secondary preventive medical therapy.The patient is currently under ongoing follow-up care.CABG is an effective treatment for myocardial bridge.However,based on the case reported in this study,we recommend careful evaluation of whether a patient may benefit from CABG.