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.

High mobility group box 1 (HMGB1), when released extracellularly, plays a pivotal role in the development of spinal cord synapses and exacerbates autoimmune diseases within the central nervous system. In experimental autoimmune encephalomyelitis (EAE), a condition that models multiple sclerosis, the levels of extracellular HMGB1 and interleukin-33 (IL-33) have been found to be inversely correlated. However, the mechanism by which IL-33 deficiency enhances HMGB1 release during EAE remains elusive. Our study elucidates a potential signaling pathway whereby the absence of IL-33 leads to increased binding of P300/CBP-associated factor with HMGB1 in the nuclei of astrocytes, upregulating HMGB1 acetylation and promoting its release from astrocyte nuclei in the spinal cord of EAE mice. Conversely, the addition of IL-33 counteracts the TNF-α-induced increase in HMGB1 and acetylated HMGB1 levels in primary astrocytes. These findings underscore the potential of IL-33-associated signaling pathways as a therapeutic target for EAE treatment.
Animals ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; Astrocytes/metabolism* ; Interleukin-33/metabolism* ; HMGB1 Protein/metabolism* ; Acetylation ; Mice, Knockout ; Mice, Inbred C57BL ; p300-CBP Transcription Factors/metabolism* ; Mice ; Spinal Cord/metabolism* ; Cells, Cultured ; Female ; Signal Transduction

Loss of protein homeostasis is a hallmark of cellular senescence, and ribosome pausing plays a crucial role in the collapse of proteostasis. However, our understanding of ribosome pausing in senescent cells remains limited. In this study, we utilized ribosome profiling and G-quadruplex RNA immunoprecipitation sequencing techniques to explore the impact of RNA G-quadruplex (rG4) on the translation efficiency in senescent cells. Our results revealed a reduction in the translation efficiency of rG4-rich genes in senescent cells and demonstrated that rG4 structures within coding sequence can impede translation both in vivo and in vitro. Moreover, we observed a significant increase in the abundance of rG4 structures in senescent cells, and the stabilization of the rG4 structures further exacerbated cellular senescence. Mechanistically, the RNA helicase DHX9 functions as a key regulator of rG4 abundance, and its reduced expression in senescent cells contributing to increased ribosome pausing. Additionally, we also observed an increased abundance of rG4, an imbalance in protein homeostasis, and reduced DHX9 expression in aged mice. In summary, our findings reveal a novel biological role for rG4 and DHX9 in the regulation of translation and proteostasis, which may have implications for delaying cellular senescence and the aging process.
G-Quadruplexes ; Cellular Senescence ; Ribosomes/genetics* ; Humans ; Animals ; Mice ; DEAD-box RNA Helicases/genetics* ; Protein Biosynthesis ; RNA/chemistry* ; Neoplasm Proteins

Pancreatic cancer is a kind of highly malignant tumor with a low survival rate and poor prognosis. The effectiveness of gemcitabine as a first-line chemotherapy drug is limited; however, it can activate dendritic cells and improve antigen presentation which increase the sensitivity of tumor cell to immunotherapy. Although immunotherapy has made some advancements in cancer treatment, the therapeutic benefit of programmed cell death receptor 1/programmed death receptor-ligand 1 (PD-1/PD-L1) blockade therapy remains relatively low. The chemokine C-X-C chemokine ligand 12 (CXCL12) contributes to an immunosuppressive tumor microenvironment by recruiting immunosuppressive cells. The receptor C-X-C motif chemokine receptor 4 (CXCR4), highly expressed in various tumors including pancreatic cancer, plays a crucial role in tumor development and progression. In this study, the anti-tumor immune response of human peripheral blood mononuclear cell (hPBMC) was enhanced using the combination of BsNb PX4 (anti-PD-L1&CXCR4 bispecific nanobody) and gemcitabine. In a co-culture system of gemcitabine-pretreated hPBMCs with tumor cells, the BsNb PX4 synergized gemcitabine to improve the cytotoxic activity of hPBMCs against tumor cells. Flow cytometry analysis confirmed increased ratio of CD8⁺ to CD4⁺ T cells in combination treatment. In NOD/SCID mice bearing pancreatic cancer, the combination treatment exhibited more infiltration of CD8⁺ T cells into tumor tissues, contributing to an effective anti-tumor response. This study presents potential new therapies for the treatment of pancreatic cancer. Ethical approval was obtained for collection of hPBMC samples from the Local Ethics Committee of Shanghai Jiao Tong University. All animal experiments were approved by the Animal Ethic Committee of Shanghai Jiao Tong University (authorizing number: A2024246).

ObjectiveNon-invasive magnetic stimulation technology has been widely used in the treatment of Alzheimer’s disease (AD), but there is a lack of convenient and timely methods for evaluating and providing feedback on the effectiveness of the stimulation, which can be used to guide the adjustment of the stimulation protocol. This study aims to explore the possibility of heart rate variability (HRV) in diagnosing AD and guiding AD magnetic stimulation intervention techniques. MethodsIn this study, we used a 40 Hz, 10 mT pulsed magnetic field to expose AD mouse models to whole-body exposure for 18 d, and detected the behavioral and electroencephalographic signals before and after exposure, as well as the instant electrocardiographic signals after exposure every day. ResultsUsing one-way ANOVA and Pearson correlation coefficient analysis, we found that some HRV indicators could identify AD mouse models as accurately as behavioral and electroencephalogram(EEG) changes (P<0.05) and significantly distinguish the severity of the disease (P<0.05), including rMSSD, pNN6, LF/HF, SD1/SD2, and entropy arrangement. These HRV indicators showed good correlation and statistical significance with behavioral and EEG changes (r>0.3, P<0.05); HRV indicators were significantly modulated by the magnetic field exposure before and after the exposure, both of which were observed in the continuous changes of electrocardiogram (ECG) (P<0.05), and the trend of the stimulation effect was more accurately observed in the continuous changes of ECG. ConclusionHRV can accurately reflect the pathophysiological changes and disease degree, quickly evaluate the effect of magnetic stimulation, and has the potential to guide the pattern of magnetic exposure, providing a new idea for the study of personalized electromagnetic neuroregulation technology for brain diseases.

BACKGROUND:At present,there are few reports on the postoperative efficacy of arthroscopic coracoid tunnel-free suspension fixation and coracoid single tunnel fixation in the treatment of acromioclavicular joint dislocation at home and abroad.The specific clinical efficacy of the two procedures and whether there are other risks need to be explored. OBJECTIVE:To compare the short-term postoperative clinical efficacy of arthroscopic TightRope band plate fixation with single tunnel fixation of the coracoid process and tunnel-free suspension fixation of the coracoid process in the treatment of acute type Ⅲ-Ⅴ acromioclavicular joint dislocation. METHODS:A retrospective analysis was performed in 45 patients with acromioclavicular joint dislocation who met the inclusion criteria admitted to the Sixth Affiliated Hospital of Xinjiang Medical University from June 2019 to September 2022,and were divided into coracoid single tunnel fixation group(20 cases)and coracoid tunnel-free suspension fixation group(25 cases)according to the surgical treatment plan.Operation time,incision length,blood loss,Constant-Murley score,visual analogue scale score,the American Shoulder and Elbow Surgeons(ASES)score and intraoperative and postoperative complications of the shoulder joint before operation,3 months after surgery and the last follow-up were compared between the two groups. RESULTS AND CONCLUSION:All patients successfully completed the operation,and there was no important nerve or blood vessel damage during the operation.The operation time of the coracoid tunnel-free suspension fixation group was significantly shorter than that of the coracoid tunnel-free suspension fixation group(P<0.05).There was no significant difference in intraoperative blood loss and incision length between the two groups(P>0.05).All patients were followed up for 12 to 24 months,with an average of(15.29±2.73)months.In the coracoid single tunnel fixation group,at 3 months after operation and the final follow-up,the visual analogue scale score was significantly lower than the preoperative score(P<0.05);Constant-Murley score and ASES score were significantly increased compared with the preoperative values(P<0.05).In the coracoid tunnel-free suspension fixation group,at 3 months after operation and the final follow-up,the visual analogue scale score was significantly lower than the preoperative score(P<0.05);the Constant-Murley score and the ASES score were both significantly higher than the preoperative scores(P<0.05).At 3 months after operation,the Constant-Murley score of the coracoid tunnel-free suspension fixation group was higher than that of the coracoid single tunnel fixation group(P<0.05),while there was no significant difference in visual analogue scale and ASES scores between the two groups(P>0.05).There was also no significant difference in the visual analogue scale,Constant-Murley,and ASES scores between the two groups at the corresponding time points before surgery and at the final follow-up(P>0.05).Intraoperative and postoperative complications:In the coracoid single tunnel fixation group,there was one case of coracoid cortical rupture and fracture during the tunnel drilling during the operation,and one case of a loss of reduction at 3 months after operation,which was repositioned and fixed with hook plate transposition of the coracoacromial ligament.All patients had good acromioclavicular joint function recovery and no re-dislocation at the final follow-up.All patients in the coracoid tunnel-free suspension fixation group did not suffer from coracoid fractures,loss of reduction and other complications during surgery,postoperatively and at the last follow-up.To conclude,these two arthroscopic treatments for acute type Ⅲ-Ⅴ acromioclavicular joint dislocation have the advantages of less trauma,reliable reduction and fixation,and good recovery of shoulder joint function after operation.However,compared with the coracoid single tunnel technique,the coracoid tunnel-free suspension fixation requires shorter time,faster recovery of shoulder joint function in the short term,and avoids the establishment of bone tunnels on the coracoid process,which reduces the probability of iatrogenic fracture of the coracoid process during operation and provides a higher degree of safety.

A recombinant adenovirus(rAd)for expression of Mycobacterium tuberculosis(M.tb)c-di-AMP phosphodiesterase CnpB was constructed,and its induced humoral immune response was detected.The codon-optimized gene of M.tb CnpB was cloned into the adenoviral plasmid pcADV.The recombinant plasmid pcADV-CnpB was transfected into HEK293T cells,and expression was detected with Western blot.The recombinant plasmid pcADV-CnpB and the backbone plasmid were co-transfected into HEK293T cells to obtain the recombinant adenovirus rAd-CnpB.rAd-CnpB was amplified in HEK293T cells,and the target protein expression of rAd-CnpB was detected with Western blot and immunofluorescence.Mice were immunized with rAd-CnpB intranasally,and their sera and bronchoalveolar lavage fluid(BALF)were collected.ELISA was used to detect levels of antigen-specific antibodies.Restriction enzyme digestion and sequencing indicated that the recombinant plasmid pcADV-CnpB was successfully constructed and led to protein expression in eukaryotic cells.rAd-CnpB was packaged and produced in HEK293T cells.After amplification and purification,rAd-CnpB with a titer of 5.53×1010 PFU/mL was obtained.rAd-CnpB led to CnpB expression in HEK293T cells.Intranasal immunization with rAd-CnpB increased levels of IgG and secretory IgA in BALF and led to high levels of IgG in sera.rAd-CnpB,the recombinant adenovirus for expression of c-di-AMP phosphodiesterase CnpB was successfully constructed,and was found to induce antigen-specific humoral and mucosal immune responses through mucosal immunization.Thus,rAd-CnpB may be used in further research on new TB vaccine strategies.

Objective To investigate the effects of γ-glutamyl hydrolase(GGH)rs11545078 C＞T polymorphisms on serum concentrations,chemotherapy toxicities of methotrexate(MTX),and prognosis in children with intracranial tumors.Methods Peripheral blood samples were obtained from children with intracranial tumors to extract genome DNA.Matrix-assisted laser desorption/ionization-time of flight mass spectrometry was used to detect the genotypes of GGH rs11545078 C＞T polymorphisms.Fluorescence polarization immunoassay was employed to determine the serum concentrations of MTX.The incidences of toxicities,relapse,and metastasis were recorded after chemotherapy with MTX.The associations of GGH rs11545078 C＞T polymorphisms with concentration-to-dose ratios(C/D ratios),chemotherapy toxicities of MTX,relapse,and metastasis of tumors were analyzed.Results A total of 75 children were included in the present study.The frequencies of rs11545078 CC and CT genotypes were 82.67％and 17.33％,respectively.The frequencies of C and T alleles were 91.33％and 8.67％,respectively.There were no statistically significant differences for these frequencies among the children with intracranial tumors,the children with acute lymphoblastic leukemia,and the health population in Beijing.Children with the CC genotype had higher median C/D ratios of MTX in 24 and 42 h(25.19 and 0.14 μmol·L-1 per g·m-2,respectively),higher metastasis rates(46.77％),and lower relapse rates(17.74％)than those in CT genotype carriers(22.01 and 0.11 μmol·L-1 per g·m-2,38.46％,and 30.77％,respectively),and the differences were no statistically significant(all P＞0.05).The incidences of gastrointestinal disorders(76.92％)in children with the CT genotype were significantly higher than those in CC genotype carriers(45.16％,P＜0.05).There were no statistically significant differences in the incidences of other adverse events between patients with the CC genotype and patients with the CT genotype(all P＞0.05).Conclusion GGH rs11545078 CT might be a risk factor for gastrointestinal disorders in children with intracranial tumors treated with MTX.

Objective To investigate the mechanism by which artesunate(ART)attenuates intestinal mucosal barrier damage in acute graft-versus-host disease(aGVHD)and the synergistic effect of ART in combination with dexamethasone(DXM)in the treatment of aGVHD mice.Methods The aGVHD mouse model was established by bone marrow haematopoietic stem cell transplantation.The mice were divided into 9 groups,including normal mice control(Ctrl),aGVHD mice(aGVHD),normal mice receiving ART[30 mg/(kg·d)],aGVHD mice receiving low-dose ART[10 mg/(kg·d)],aGVHD mice receiving medium-dose ART[30 mg/(kg·d)],aGVHD mice receiving high-dose ART[50 mg/(kg·d)],aGVHD mice receiving DXM[20 mg/(kg·d)],aGVHD mice receiving ART[30 mg/(kg·d)]and DXM[20 mg/(kg·d)],and aGVHD mice receiving ART[30 mg/(kg·d)]and halved DXM[10 mg/(kg·d)].Survival rate and clinical parameters were assessed.HE staining and Alcian blue-periodic acid-Schiff(AB-PAS)staining were used to observe the histopathological changes in the intestinal mucosa of the mice;Real-time PCR,Western blotting and immunohistochemistry were used to detect the structure of the intestinal mucosal barrier,the T cell differentiation related transcription factors and cytokines,and the key enzymes of energy metabolism.Flow cytometry was used to detect the T helper cell 17(Th17)and regulatory T cells(Treg).Results After 30 days of ART treatment,aGVHD mice showed significant relief of systemic symptoms and increase in survival rate.In aGVHD mice treated with ART,the intestinal mucosal barrier structure was restored,and the intestinal mucosal permeability was reduced.The activity of AMP-activated protein kinase(AMPK)/mTOR pathway was inhibited,and the energy metabolism pattern of T cells was dominated by fatty acid synthesis.The balance of Th17/Treg was restored due to the decrease of Th 17 and the increase of Treg.The effect of ART+DXM treatment on aGVHD mice was comparable to that of DXM treatment alone,and the survival rate of mice was higher.In particular,the recovery of the intestinal mucosal barrier function was most obvious in the mice treated with ART+half-dose DXM.Conclusion ART reduces the immune injury of allo-T cells to the intestinal mucosal barrier by recovering the Th17/Treg balance,thus maintaining the integrity of the intestinal mucosal barrier function.The synergistic effect of ART and DXM combination treatment in aGVHD mice can reduce the incidence of DXM side effects by decreasing the dosage of DXM.