Aim To investigate the effect of exosomes derived from bone marrod-derived mesenchymal stem cells(BMSCs)on dexamethasone-induced C2C12 muscular canal atrophy.Methods(1)C57BL/6J mouse bone marrow mesenchymal stem cells were isola-ted and cultured by whole bone marrow adhesion meth-od.(2)Extraction and identification of BMSCs EXOs were performed.(3)Myogenic differentiation of C2C12 cells was carried out.(4)The successfully differentia-ted myotubes were divided into the control group(cul-tured in 2％equine serum medium for 48 h),dexam-ethasone group(dexamethasone,DEX,10 μmol·L-1 concentration of DEX interfered with myotubes for 48 h),and exosomes group(exosomes,EXOs,interfered with myotubes for 48 h),exosome inhibitor group(exo-somes extracted from BMSCs after 10 μm GW4869 in-tervention,interfered with myotubes for 48 h).48 h later,the morphology and diameter of muscle tubes were observed and measured by microscope.Cell via-bility of each group was detected by CCK-8 method.The expression levels of atrogin-1 and MuRF-1,myo-genic differentiation antigen(MYOD)in each group were detected by Western blot.Results BMSCs were long spusiform,and BMSCS-EXOS showed a circular bilayer structure under transmission electron microsco-py,with a diameter of about 200 nm.CD9,CD63 and CD81 were highly expressed.Compared with the con-trol group,cell activity in DEX group decreased(P＜0.01),diameter of myotubes decreased(P＜0.01),expressions of atrogin-1(P＜0.05)and MuRF-1(P＜0.01)were significantly up-regulated,and expression of MYOD(P＜0.01)was significantly down-regula-ted.Compared with the DEX group,cell activity in the BMSCs-EXOs group increased(P＜0.01),diameter of myotubes increased(P＜0.01),expressions of atrogin-1(P＜0.05)and MuRF-1(P＜0.01)were signifi-cantly down-regulated,and expression of MYOD(P＜0.01)was up-regulated.Compared with the BMSCs-EXOs group,cell activity of the BMSCs-EXOs(GW4869)group decreased(P＜0.05),diameter of myotubes decreased(P＜0.01),expressions of atrog-in-1(P＜0.05)and MuRF-1(P＜0.05)were up-regulated,and expression of MYOD(P＜0.01)was down-regulated.Conclusion Bone marrow mesen-chymal stem cell-derived exosomes(BM-MSCs-EXOs)inhibit dexamethasone-induced C2C12 muscle tube at-rophy.

Aim To investigate the effect of exosomes derived from bone marrod-derived mesenchymal stem cells(BMSCs)on dexamethasone-induced C2C12 muscular canal atrophy.Methods(1)C57BL/6J mouse bone marrow mesenchymal stem cells were isola-ted and cultured by whole bone marrow adhesion meth-od.(2)Extraction and identification of BMSCs EXOs were performed.(3)Myogenic differentiation of C2C12 cells was carried out.(4)The successfully differentia-ted myotubes were divided into the control group(cul-tured in 2％equine serum medium for 48 h),dexam-ethasone group(dexamethasone,DEX,10 μmol·L-1 concentration of DEX interfered with myotubes for 48 h),and exosomes group(exosomes,EXOs,interfered with myotubes for 48 h),exosome inhibitor group(exo-somes extracted from BMSCs after 10 μm GW4869 in-tervention,interfered with myotubes for 48 h).48 h later,the morphology and diameter of muscle tubes were observed and measured by microscope.Cell via-bility of each group was detected by CCK-8 method.The expression levels of atrogin-1 and MuRF-1,myo-genic differentiation antigen(MYOD)in each group were detected by Western blot.Results BMSCs were long spusiform,and BMSCS-EXOS showed a circular bilayer structure under transmission electron microsco-py,with a diameter of about 200 nm.CD9,CD63 and CD81 were highly expressed.Compared with the con-trol group,cell activity in DEX group decreased(P＜0.01),diameter of myotubes decreased(P＜0.01),expressions of atrogin-1(P＜0.05)and MuRF-1(P＜0.01)were significantly up-regulated,and expression of MYOD(P＜0.01)was significantly down-regula-ted.Compared with the DEX group,cell activity in the BMSCs-EXOs group increased(P＜0.01),diameter of myotubes increased(P＜0.01),expressions of atrogin-1(P＜0.05)and MuRF-1(P＜0.01)were signifi-cantly down-regulated,and expression of MYOD(P＜0.01)was up-regulated.Compared with the BMSCs-EXOs group,cell activity of the BMSCs-EXOs(GW4869)group decreased(P＜0.05),diameter of myotubes decreased(P＜0.01),expressions of atrog-in-1(P＜0.05)and MuRF-1(P＜0.05)were up-regulated,and expression of MYOD(P＜0.01)was down-regulated.Conclusion Bone marrow mesen-chymal stem cell-derived exosomes(BM-MSCs-EXOs)inhibit dexamethasone-induced C2C12 muscle tube at-rophy.

Objective:To explore the expression regulation of lipid metabolism gene ABHD5 in testes.Methods:Differential gene analysis was performed by integrating databases of TCGA and GTEx to identify the target gene ABHD5.The expression trends of ABHD5 gene in testicular carcinoma tissue were analyzed.Human testis single-cell atlases were obtained from the Human Protein Atlas and Male Health Atlas databases to determine the expression distribution of ABHD5 across different testicular cell types.Additionally,the GTEx database was utilized to visualize the expression pattern of ABHD5 in the testis,thereby enhancing the understanding of its transcriptional profile.The relationship between ABHD5 expression and age was assessed through integrated database analysis.Western blotting and immunofluorescence were performed to detect differential expressions of ABHD5 in testicular tissues of young and aged mice respectively.Results:The TCGA database indicated that the expression of ABHD5 in human testicular carcinoma tissue was significantly lower than that in normal testicular tissue which showed a negative correlation with patient survival.ABHD5 was highly ex-pressed in germ cells of the testis reveaked from Human Protein Atlas and Male Health Atlas databases.The stability of ABHD5 protein was crucial for testicular tissue,and its expression decreased with age.Furthermore,Western blot and immunofluorescence staining demonstrated that ABHD5 expression in the testicular tissue of aged mice was significantly lower than that in young mice.Conclu-sion:ABHD5 plays an important role in testicular tissue,and may be inseparable from testicular tumors and reproductive aging.How-ever,its mechanism of action remains to be further studied.

Lung cancer poses a serious threat to global public health security.Chemotherapy,as the main strategy for cancer treatment,faces challenges such as high toxicity and drug resistance.Anticancer peptides have the potential of being developed into new anticancer drugs due to their advantages of broad-spectrum anticancer activity,rapid action,and difficulty in generating drug resistance,but they also face shortcomings such as weak activity and strong toxic side effects.The weakly acidic microenvironment of tumors(pH 6.5-6.8)provides a good idea for the design of anticancer peptides of high-efficiency and low-toxicity.Previously,we designed the acid-sensitive antibacterial peptide pHly-1 using the wolf spider(Lycosa singoriensis)toxin Lycosin-Ⅰ as a template.In this study,we found that pHly-1 also had acid-sensitive anticancer activity.Further alanine scanning analysis of pHly-1 was carried out,and we ob-tained a mutant pHTP-2 with better acid sensitivity,whose IC50(half maximal inhibitory concentration)against A549 cells was 15.68 μmol/L at pH 6.6 and was greater than 100 μmol/L at pH 7.4.At pH 6.6,pHTP-2 could act on various lung cancer cell lines and induce the death of A549 cells by rapid ly-sis;at pH 7.4,500 μmol/L pHTP-2 had weak toxicity to red blood cells(the hemolysis rate was ap-proximately 38％)and primary myocardial cells(the inhibition rate was 49.7％,with P＜0.05).Analy-sis of its charge,particle size,morphology,and secondary structure showed that at pH 6.6,the histidine in the sequence of pHTP-2 was protonated,increasing the positive charge(P＜0.01),decreasing the hy-drated particle size(P＜0.05)and forming an α-helical structure to induce membrane lysis of A549 cells.At pH 7.4,it was deprotonated,the positive charge decreases,a β-sheet structure was formed and self-aggregation occurred,limiting its effect on the A549 cell membrane and showing weak activity.In summary,pHTP-2 could respond to the weakly acidic microenvironment of tumors to exert selective cyto-toxic activity,effectively overcoming the shortcomings of anticancer peptides such as low efficiency and high toxicity.Our findings suggest that it is a high-quality lead molecule for anticancer drugs.

Lung cancer poses a serious threat to global public health security.Chemotherapy,as the main strategy for cancer treatment,faces challenges such as high toxicity and drug resistance.Anticancer peptides have the potential of being developed into new anticancer drugs due to their advantages of broad-spectrum anticancer activity,rapid action,and difficulty in generating drug resistance,but they also face shortcomings such as weak activity and strong toxic side effects.The weakly acidic microenvironment of tumors(pH 6.5-6.8)provides a good idea for the design of anticancer peptides of high-efficiency and low-toxicity.Previously,we designed the acid-sensitive antibacterial peptide pHly-1 using the wolf spider(Lycosa singoriensis)toxin Lycosin-Ⅰ as a template.In this study,we found that pHly-1 also had acid-sensitive anticancer activity.Further alanine scanning analysis of pHly-1 was carried out,and we ob-tained a mutant pHTP-2 with better acid sensitivity,whose IC50(half maximal inhibitory concentration)against A549 cells was 15.68 μmol/L at pH 6.6 and was greater than 100 μmol/L at pH 7.4.At pH 6.6,pHTP-2 could act on various lung cancer cell lines and induce the death of A549 cells by rapid ly-sis;at pH 7.4,500 μmol/L pHTP-2 had weak toxicity to red blood cells(the hemolysis rate was ap-proximately 38％)and primary myocardial cells(the inhibition rate was 49.7％,with P＜0.05).Analy-sis of its charge,particle size,morphology,and secondary structure showed that at pH 6.6,the histidine in the sequence of pHTP-2 was protonated,increasing the positive charge(P＜0.01),decreasing the hy-drated particle size(P＜0.05)and forming an α-helical structure to induce membrane lysis of A549 cells.At pH 7.4,it was deprotonated,the positive charge decreases,a β-sheet structure was formed and self-aggregation occurred,limiting its effect on the A549 cell membrane and showing weak activity.In summary,pHTP-2 could respond to the weakly acidic microenvironment of tumors to exert selective cyto-toxic activity,effectively overcoming the shortcomings of anticancer peptides such as low efficiency and high toxicity.Our findings suggest that it is a high-quality lead molecule for anticancer drugs.

This article reports a first case of combined infection with severe fever with thrombocytopenia syndrome(SFTS)and scrub typhus in Dalian City.The patient was admitted to the hospital due to recurrent fever for 7 days and loss of consciousness for 1 day.Pathogen metagenomic sequencing(mNGS),SFTSV quantitative PCR,and enzyme-linked immunosorbent assay(ELISA)IgM tests were performed,showing positive results for Orientia tsutsugamushi and SFTSV nucleic acids.Based on clinical manifestations and epidemiological history,the patient was diagnosed with combined infections.

ObjectiveIn nature, objects cast shadows due to illumination, forming the basis for stereoscopic perception. Birds need to adapt to changes in lighting (meaning they can recognize stereoscopic shapes even when shadows look different) to accurately perceive different three-dimensional forms. However, how neurons in the key visual brain area in birds handle these lighting changes remains largely unreported. In this study, pigeons (Columba livia) were used as subjects to investigate how neurons in pigeon’s ventrolateral mesopallium (MVL) represent stereoscopic shapes consistently, regardless of changes in lighting. MethodsVisual cognitive training combined with neuronal recording was employed. Pigeons were first trained to discriminate different stereoscopic shapes (concave/convex). We then tested whether and how light luminance angle and surface appearance of the stereoscopic shapes affect their recognition accuracy, and further verify whether the results rely on specify luminance color. Simultaneously, neuronal firing activity of neurons was recorded with multiple electrode array implanted from the MVL during the presentation of difference shapes. The response was finally analyzed how selectively they responded to different stereoscopic shapes and whether their selectivity was affected by the changes of luminance condition (like lighting angle) or surface look. Support vector machine (SVM) models were trained on neuronal population responses recorded under one condition (light luminance angle of 45°) and used to decode responses under other conditions (light luminance angle of 135°, 225°, 315°) to verify the invariance of responses to different luminance conditions. ResultsBehavioral results from 6 pigeons consistently showed that the pigeons could reliably identify the core 3D shape (over 80% accuracy), and this ability wasn’t affected by changes in light angle or surface appearance. Statistical analysis of 88 recorded neurons from 6 pigeons revealed that 83% (73/88) showed strong selectivity for specific 3D shapes (selectivity index>0.3), and responses to convex shapes were consistently stronger than to concave shapes. These shape-selective responses remained stable across changes in light angle and surface appearance. Neural patterns were consistent under both blue and orange lighting. The decoding accuracy achieves above 70%, suggesting stable responses under different conditions (e.g., different lighting angles or surface appearance). ConclusionNeurons in the pigeon MVL maintain a consistent neural encoding pattern for different stereoscopic shapes, unaffected by illumination or surface appearance. This ensures stable object recognition by pigeons in changing visual environments. Our findings provide new physiological evidence for understanding how birds achieve stable perception (“invariant neural representations”) while coping with variations in the visual field.

Plutonium isotopes(238Pu,239Pu,240Pu and 241Pu)in the environment are important"fingerprint"nuclides in the study of nuclear activity traceability.The content of plutonium isotopes in the environmental metrics is usually very low,and the measurement of these isotopes,especially 238Pu,using mass spectrometry is seriously interfered with by the coexisting 238U.The analysis of several plutonium isotopes in soil usually requires combination of multiple measurement techniques,which leads to a long analysis time and large uncertainty in the isotope ratio.In this work,the hydrous titanium oxide(HTiO)precipitated by the hydrolysis of titanium oxydichloride(TiOCl2)under near-neutral condition was used to preconcentrate plutonium from the soil digestion solution,and the highly efficient decontamination of 238U in the sample was achieved by TK200 resin column chromatography with a decontamination factor of 108.Simulation resuts of density functional theory(DFT)showed that NH3 was considered as a promising reaction gas to eliminate the interference of 238U from 238Pu measurement using mass spectrometry due to the significant discrepancy of the chemical reactivity of U+and Pu+with the reactive gas NH3.Experiments confirmed that by optimizing the flow rates of collision gas(He)and reaction gas(NH3),the interference of 238U could be effectively suppressed,and the decontamination factor of 238U was 104.Combined with chemical separation,the overall decontamination factor of 238U could reach 1012 by using the developed method.By combining chemical separation and tandem quadrupole inductively coupled plasmon-mass spectrometry(ICP-MS/MS)measurement,the simultaneous determination of four ultra-trace plutonium isotopes in soil was realized,and the detection limit of plutonium isotopes was at the femtogram level.Analysis of the international standard reference materials(NIST-SRM-4357 and IAEA-384)showed that the established method could be successfully used for the accurate analysis of ultra-trace four plutonium isotopes(238Pu,239Pu,240Pu and 241Pu)in soil samples.

PURPOSE: Bone cement-reinforced fenestrated pedicle screws (FPSs) have been widely used in the internal fixation and repair of the spine with osteoporosis in recent years and show significant improvement in fixation strength and stability. However, compared with conventional reinforcement methods, the advantages of bone cement-reinforced FPSs remain undetermined. This article compares the effects of fenestrated and conventional pedicle screws (CPSs) combined with bone cement in the treatment of osteoporosis. METHODS: A clinical control study of FPSs and CPSs combined with bone cement reinforcement in osteoporotic vertebral internal fixation was performed using the database PubMed, Embase, Cochrane Library, CNKI, the Wanfang, and the China Biomedical Literature Service System. Two evaluators screened the relevant literature in strict accordance with the inclusion criteria (diagnosis of participants, type of clinical study, treatment with FPS and CPS, and outcome indicators) and exclusion criteria (duplicate literature and missing or incorrect data) and independently conducted data extraction and quality evaluation. Clinical control studies of direct comparison between FPS and CPS combined with bone cement reinforcement in patients who were definitively diagnosed with thoracolumbar fractures or spinal degenerative diseases were included. Quality evaluation was conducted using the Cochrane risk bias evaluation tool for randomized controlled studies and using the Newcastle-Ottawa scale for retrospective case-control studies. RevMan software (version 5.3) was used for the meta-analysis to compare the clinical efficacy, radiological results, and related complications of the 2 methods. RESULTS: A total of 13 articles were included, including 7 randomized controlled studies and 6 retrospective case-control studies. There were 909 patients in these studies, 451 in the FPS and polymethyl methacrylate (FPS & PMMA) group and 458 in the CPS and polymethyl methacrylate (CPS & PMMA) group. The results of the meta-analysis showed that there was no significant difference between the 2 groups in operation time, hospital stay, visual analogue score, Japanese orthopaedic association score, Oswestry disability index score, Cobb angle, vertebral body deformation index and fusion rate (p > 0.05). The mean difference of intraoperative bleeding volume was -10.45, (95% confidence intervals (CI) (-16.92, -3.98), p = 0.002), the mean difference of loss height of the anterior edge of the vertebral body after surgery was -0.69 (95% CI (-0.93, -0.44), p < 0.001), and the relative risk (RR) of overall complication rate was 0.43 (95% CI (0.27, 0.68), p < 0.001), including the RR of bone cement leakage rate was 0.57 (95% CI (0.39, 0.85), p = 0.005). The screw loosening rate (RR = 0.26, 95% CI (0.13, 0.54), p < 0.001) of the FPS group was significantly lower than that of the CPS group. CONCLUSION The existing clinical evidence shows that compared with the CPS combined with bone cement, the use of FPS repair in the internal fixation of an osteoporotic vertebral body can reduce the amount of intraoperative bleeding, be more conducive to maintaining the height of the vertebral body, and significantly reduce the incidence of postoperative complications such as bone cement leakage and screw loosening.
Humans ; Pedicle Screws ; Bone Cements ; Spinal Fractures/surgery* ; Osteoporotic Fractures/surgery* ; Fracture Fixation, Internal/instrumentation*

Triple-negative breast cancer is therapeutically challenging due to the low expression of tumor markers and 'cold' tumor immunosuppressive microenvironment. Here, we present a dual-targeting peptide-drug conjugate (PDC) for tumor inhibition. Our PDC efficiently and selectively delivers cytotoxic Monomethyl Auristatin E (MMAE) into tumor cells via C-X-C chemokine receptor type 4 (CXCR4) and folate receptor 1 (FOLR1) for synergistic inhibition of growth and metastasis. Our results show that the dual-targeting PDC has potent antitumor activity in cultured human cells and several murine transplanted tumor models without apparent toxicity. The combination of dual-targeting PDC and radiotherapy modulates the tumor immunosuppressive microenvironment by increasing CD8⁺ T cell infiltration and attenuating the proportion of myeloid-derived suppressor and regulatory T cells. Therefore, our dual-targeting PDC represents a promising new strategy for cancer therapy that rebalances the immune system and promotes tumor regression.