Apurinic/apyrimidinic endonuclease 1(APE 1)is a multifunctional protein that plays important roles in DNA repair and regulation of gene expression.Because APE 1 is overexpressed in various cancers,it can serve as a cancer biomarker for aiding clinical diagnosis,guiding therapy,and monitoring prognosis.On this basis,a label-free fluorescent probe was designed based on the primer exchange reaction(PER)strategy for highly sensitive detection of APE 1 activity.In the absence of APE 1,the structure of catalytic hairpin(HP)was stable and could not form G-quadruplex.Therefore,the background fluorescence of this sensing system was very low due to the dissociation of thioflavin T(ThT).In the presence of APE 1,the apurinic/apyrimidinic(AP)site of HP was cleaved by APE 1 and a short nucleic acid fragment that acted as a primer to initiate PER was generated.After PER reaction,a large number of G-quadruplex were produced,which could specifically bind with ThT and resulted in significant increase of fluorescence signal.The combination of low background design of HP and PER amplification made this biosensor had high sensitivity with a detection limit(3σ)of 0.0008 U/mL.Furthermore,the primer sequence was directly generated by the cleavage of APE 1 without additional addition,which not only increased the specificity of the reaction,but also simplified the experiment procedure.Moreover,the use of label-free fluorescence signal reduced the cost of the experiment,and realized rapid detection of APE 1.Finally,this sensor was used to detect APE 1 in human serum samples with spiked recoveries of 91%-104%,proving great potential in study of biological enzyme.

AIM To investigate the effects of Xuesaitong Capsules(Panax notoginseng saponins)on ischemia/reperfusion injury in a mouse model of skin frostbite.METHODS The mice were randomly divided into the control group,the model group,the dexamethasone group(1 mg/kg),and the low-dose,medium-dose,and high-dose Xuesaitong Capsules groups(0.036,0.072,and 0.144 g/kg),with eight mice in each group.A frostbite model was established using a dry ice-cooled ceramic(ferrite)magnet.On the 2nd day after modeling,each group started its corresponding dosing by gavage for 14 consecutive days.The wound healing,histopathological changes,and serum levels of high-sensitivity C-reactive protein(hs-CRP),thromboxane B2(TXB2),6-keto-prostaglandin F1α(6-K-PGF1α),nitric oxide(NO)and endothelin(ET)were assessed using ELISA.The superoxide dismutase(SOD)activity and malondialdehyde(MDA)levels in skin tissues were measured biochemically.The protein expressions of tumor necrosis factor(TNF)-α,interleukin(IL)-1β,IL-6,Toll-like receptor(TLR)4 and phosphorylated nuclear factor-KB p65(p-NF-κB p65)in skin tissues were determined by Western blot.Additionally,LncRNA H19 mRNA expression in skin tissues was evaluated using RT-qPCR.RESULTS After the final administration,compared with the control group,the model group exhibited partial scab detachment,wound healing,and larger wound areas;hyperkeratosis with incomplete keratinization,detachment of the dermis and subcutaneous tissue,partial loss of appendages,subcutaneous edema,and dilated,congested,and hemorrhagic stromal vessels with extensive lymphocyte infiltration revealed by the histopathological examination;elevated serum levels of hs-CRP,TXB2,and ET(P＜0.05,P＜0.01);decreased 6-K-PGF1α and NO levels(P＜0.05,P＜0.01);reduced SOD activity in skin tissues(P＜0.01);increased MDA levels(P＜0.01);and upregulated protein expressions of TNF-α,IL-1β,IL-6,TLR4 and p-NF-κB p65,as well as LncRNA H19 mRNA expression(P＜0.05,P＜0.01).Compared with the model group,the group intervened with high-dose Xuesaitong Capsules displayed reduced wound areas(P＜0.01);decreased serum levels of hs-CRP,TXB2 and ET(P＜0.05,P＜0.01);increased 6-K-PGF1α and NO levels(P＜0.05,P＜0.01);enhanced SOD activity(P＜0.05,P＜0.01);reduced MDA level in skin tissues(P＜0.05,P＜0.01);and down-regulated TNF-α,IL-1β,IL-6,TLR4 and p-NF-κB p65 protein expressions and suppressed LncRNA H19 mRNA expression in skin tissues as well(P＜0.05,P＜0.01).CONCLUSION Xuesaitong Capsules alleviate ischemia/reperfusion injury in frostbite-injured mice by exerting anti-inflammatory and anti oxidative stress effects and restoring vascular endothelial function mediated by the downregulation of LncRNA H19 expression and inhibition of the TLR4/NF-κB signaling pathway.

Objective:To investigate the effects and underlying mechanism of ionizing radiation on the adipogenic of mesenchymal stem cells(MSCs).Methods:Mouse MSCs were cultured in vitro and treated with 2 Gy and 6 Gy radiation with 60Co,and the radiation dose rate was 0.98 Gy/min.Bulk RNA-seq was performed on control and irradiated MSCs.The changes of adipogenic differentiation and oxidative stress pathways of MSC were revealed by bioinformatics analysis.Oil Red O staining was used to detect the adipogenic differentiation ability of MSCs in vitro,and real-time fluorescence quantitative PCR(qPCR)was used to detect the expression differences of key regulatory factors Cebpa,Lpl and Pparg after radiation treatment.At the same time,qPCR and Western blot were used to detect the effect of inhibition of Nrf2,a key factor of antioxidant stress pathway,on the expression of key regulatory factors of adipogenesis.Moreover,the species conservation of the irradiation response of human bone marrow MSCs and mouse MSC was determined by qPCR.Results:Bulk RNA-seq suggested that ionizing radiation promotes adipogenic differentiation of MSCs and up-regulation of oxidative stress-related genes and pathways.The results of Oil Red O staining and qPCR showed that ionizing radiation promoted the adipogenesis of MSCs,with high expression of Cebpa,Lpl and Pparg,as well as oxidative stress-related gene Nrf2.Nrf2 pathway inhibitors could further enhance the adipogenesis of MSCs in bone marrow after radiation.Notably,the similar regulation of oxidative pathways and enhanced adipogenesis post irradiation were observed in human bone marrow MSCs.In addition,irradiation exposure led to up-regulated mRNA expression of interleukin-6 and down-regulated mRNA expression of colony stimulating factor 2 in human bone marrow MSCs.Conclusion:Ionizing radiation promotes adipogenesis of MSCs in mice,and oxidative stress pathway participates in this effect,blocking Nrf2 further promotes the adipogenesis of MSCs.Additionally,irradiation activates oxidative pathways and promotes adipogenic differentiation of human bone marrow MSCs.

Objective:To establish an in vitro cell model simulating acute graft-versus-host disease(aGVHD)bone marrow microenvironment injury with the advantage of mouse serum of aGVHD model and explore the effect of serum of aGVHD mouse on the adipogenic differentiation ability of mesenchymal stem cells(MSCs).Methods:The 6-8-week-old C57BL/6N female mice and BALB/c female mice were used as the donor and recipient mice of the aGVHD model,respectively.Bone marrow transplantation(BMT)mouse model(n=20)was established by being injected with bone marrow cells(1 × 10'per mouse)from donor mice within 4-6 hours after receiving a lethal dose(8.0 Gy,72.76 cGy/min)of y ray general irradiation.A mouse model of aGVHD(n=20)was established by infusing a total of 0.4 ml of a mixture of donor mouse-derived bone marrow cells(1 × 107 per mouse)and spleen lymphocytes(2 × 106 per mouse).The blood was removed from the eyeballs and the mouse serum was aspirated on the 7th day after modeling.Bone marrow-derived MSCs were isolated from 1-week-old C57BL/6N male mice and incubated with 2％,5％and 10％BMT mouse serum and aGVHD mouse serum in the medium,respectively.The effect of serum in the two groups on the in vitro adipogenic differentiation ability of mouse MSCs was detected by Oil Red O staining.The expression levels of related proteins PPARy and CEBPα were detected by Western blot.The expression differences of key adipogenic transcription factors including PPARy,CEBPα,FABP4 and LPL were determined by real-time quantitative PCR(RT-qPCR).Results:An in vitro cell model simulating the damage of bone marrow microenvironment in mice with aGVHD was successfully established.Oil Red O staining showed that the number of orange-red fatty droplets was significantly reduced and the adipogenic differentiation ability of MSC was impaired at aGVHD serum concentration of 10％compared with BMT serum.Western blot experiments showed that adipogenesis-related proteins PPARy and CEBPα expressed in MSCs were down-regulated.Further RT-qPCR assay showed that the production of PPARy,CEBPα,FABP4 and LPL,the key transcription factors for adipogenic differentiation of MSC,were significantly reduced.Conclusion:The adipogenic differentiation capacity of MSCs is inhibited by aGVHD mouse serum.

Aim To explore the action mechanism of isoquercitrin(IQ)in ameliorating anxiety based on network pharmacology,cellular transcriptomics,molecu-lar docking and animal experiments.Methods The common targets of anxiety disorders and IQ were ob-tained by using relevant databases.The protein-protein interaction network,the biological function and signa-ling pathway enrichment analysis were conducted by u-sing the common targets.Primary hippocampal neurons were cultured in vitro,and corticosterone was added to induce neurons to establish a corticosterone injury mod-el.IQ treatment was added to the culture system,and transcriptomics was used to screen for differentially ex-pressed genes and enrich for differentially expressed pathways.Subsequently,the results were validated by quantitative real-time polymerase chain reaction(qRT-PCR).Possible targets and signaling pathways for IQ treatment on anxiety were speculated and screened u-sing network pharmacology,transcriptomics and molec-ular docking.The anxiety rat model was constructed,and the anxiety state of rats was evaluated after IQ in-tervention,and the protein expression level of hippo-campus was detected to verify the relevant mechanism.Results Network pharmacology,cellular transcrip-tome,and molecular docking analyses revealed that the key mechanism of IQ for anxiety may be related to the BDKRB2/PI3K/Akt signaling pathway.Animal exper-iments showed that IQ was effective in improving anxie-ty behaviour and learning memory ability in rats.IQ increased the movement distance and residence time in the central area of the open field,the time and number percentage of entries into the open arm in the elevated plus maze,and the spontaneous alternations score in the Y maze in rats,and significantly elevated protein expression of BDKRB2,PI3K,Akt and decreased pro-tein expression of NF-κB in the hippocampus.Conclu-sions Isoquercitrin can effectively treat anxiety,and the mechanism of action may be related to the regula-tion of BDKRB2/PI3K/Akt signaling pathway in hip-pocampus.

AIM To investigate the effects of Xuesaitong Capsules(Panax notoginseng saponins)on ischemia/reperfusion injury in a mouse model of skin frostbite.METHODS The mice were randomly divided into the control group,the model group,the dexamethasone group(1 mg/kg),and the low-dose,medium-dose,and high-dose Xuesaitong Capsules groups(0.036,0.072,and 0.144 g/kg),with eight mice in each group.A frostbite model was established using a dry ice-cooled ceramic(ferrite)magnet.On the 2nd day after modeling,each group started its corresponding dosing by gavage for 14 consecutive days.The wound healing,histopathological changes,and serum levels of high-sensitivity C-reactive protein(hs-CRP),thromboxane B2(TXB2),6-keto-prostaglandin F1α(6-K-PGF1α),nitric oxide(NO)and endothelin(ET)were assessed using ELISA.The superoxide dismutase(SOD)activity and malondialdehyde(MDA)levels in skin tissues were measured biochemically.The protein expressions of tumor necrosis factor(TNF)-α,interleukin(IL)-1β,IL-6,Toll-like receptor(TLR)4 and phosphorylated nuclear factor-KB p65(p-NF-κB p65)in skin tissues were determined by Western blot.Additionally,LncRNA H19 mRNA expression in skin tissues was evaluated using RT-qPCR.RESULTS After the final administration,compared with the control group,the model group exhibited partial scab detachment,wound healing,and larger wound areas;hyperkeratosis with incomplete keratinization,detachment of the dermis and subcutaneous tissue,partial loss of appendages,subcutaneous edema,and dilated,congested,and hemorrhagic stromal vessels with extensive lymphocyte infiltration revealed by the histopathological examination;elevated serum levels of hs-CRP,TXB2,and ET(P＜0.05,P＜0.01);decreased 6-K-PGF1α and NO levels(P＜0.05,P＜0.01);reduced SOD activity in skin tissues(P＜0.01);increased MDA levels(P＜0.01);and upregulated protein expressions of TNF-α,IL-1β,IL-6,TLR4 and p-NF-κB p65,as well as LncRNA H19 mRNA expression(P＜0.05,P＜0.01).Compared with the model group,the group intervened with high-dose Xuesaitong Capsules displayed reduced wound areas(P＜0.01);decreased serum levels of hs-CRP,TXB2 and ET(P＜0.05,P＜0.01);increased 6-K-PGF1α and NO levels(P＜0.05,P＜0.01);enhanced SOD activity(P＜0.05,P＜0.01);reduced MDA level in skin tissues(P＜0.05,P＜0.01);and down-regulated TNF-α,IL-1β,IL-6,TLR4 and p-NF-κB p65 protein expressions and suppressed LncRNA H19 mRNA expression in skin tissues as well(P＜0.05,P＜0.01).CONCLUSION Xuesaitong Capsules alleviate ischemia/reperfusion injury in frostbite-injured mice by exerting anti-inflammatory and anti oxidative stress effects and restoring vascular endothelial function mediated by the downregulation of LncRNA H19 expression and inhibition of the TLR4/NF-κB signaling pathway.

ObjectivePhotoacoustic pump-probe imaging can effectively eliminate the interference of blood background signal in traditional photoacoustic imaging, and realize the imaging of weak phosphorescence molecules and their triplet lifetimes in deep tissues. However, background differential noise in photoacoustic pump-probe imaging often leads to large fitting results of phosphorescent molecule concentration and triplet lifetime. Therefore, this paper proposes a novel triplet lifetime fitting method for photoacoustic pump-probe imaging. By extracting the phase of the triplet differential signal and the background noise, the fitting bias caused by the background noise can be effectively corrected. MethodsThe advantages and feasibility of the proposed algorithm are verified by numerical simulation, phantom and in vivo experiments, respectively. ResultsIn the numerical simulation, under the condition of noise intensity being 10% of the signal amplitude, the new method can optimize the fitting deviation from 48.5% to about 5%, and has a higher exclusion coefficient (0.88>0.79), which greatly improves the fitting accuracy. The high specificity imaging ability of photoacoustic pump imaging for phosphorescent molecules has been demonstrated by phantom experiments. In vivo experiments have verified the feasibility of the new fitting method proposed in this paper for fitting phosphoometric lifetime to monitor oxygen partial pressure content during photodynamic therapy of tumors in nude mice. ConclusionThis work will play an important role in promoting the application of photoacoustic pump-probe imaging in biomedicine.

A middle-aged patient presented with persistent purulent discharge from a scalp incision five years after undergoing craniotomy with artificial dura mater implantation. The wound showed no significant improvement despite a month of systemic antibiotic therapy and local debridement. Subsequent superficial ultrasonography revealed complete separation of the artificial dura mater implant area from the surrounding flap tissue, with a loss of local blood supply. Based on these findings, the artificial dura mater was surgically removed, and a free skin flap transplantation was performed to successfully cover the wound. The wound was well-healed at the 10-month postoperative follow-up.
Humans ; Scalp/diagnostic imaging* ; Middle Aged ; Male ; Epidural Abscess/etiology* ; Ultrasonography ; Surgical Flaps ; Surgical Wound Infection/surgery* ; Dura Mater/surgery*

OBJECTIVE: To prepare clinical-grade human umbilical cord-derived mesenchymal stem cells (hUC-MSC) with high expression of hematopoietic supporting factors and evaluate their stem cell characteristics. METHODS: Fetal umbilical cord tissues were collected from healthy postpartum women during full-term cesarean section. Wharton's jelly was mechanically separated and hUC-MSCs were obtained by explant culture method and enzyme digestion method in an animal serum-free culture system with addition of human platelet lysate. The phenotypic characteristics of hUC-MSCs obtained by two methods were detected by flow cytometry. The differences in proliferation ability between the two groups of hUC-MSCs were identified through CCK-8 assay and colony forming unit-fibroblast (CFU-F) assay. The differences in multilineage differentiation potential between the two groups of hUC-MSCs were identified through induction of adipogenic, osteogenic, and chondrogenic differentiation. The mRNA expression levels of hematopoietic supporting factors such as SCF, IL-3, CXCL12, VCAM1 and ANGPT1 in the two groups of hUC-MSCs were identified by real-time fluorescence quantiative PCR(RT-qPCR). RESULTS: The results of flow cytometry showed that hUC-MSCs obtained by the two methods both expressed high levels of CD73, CD90 and CD105, while lowly expressed CD31, CD45 and HLA-DR. The results of CCK-8 and CFU-F assay showed that the proliferation ability of hUC-MSCs obtained by explant culture method was better than those obtained by enzyme digestion method. The results of the triple lineage differentiation experiment showed that there was no significant difference in multilineage differentiation potential between the two grous of hUC-MSCs. The results of RT-qPCR showed that the mRNA expression levels of hematopoietic supporting factors SCF, IL-3, CXCL12, VCAM1 and ANGPT1 in hUC-MSCs obtained by explant cultrue method were higher than those obtained by enzyme digestion method. CONCLUSION Clinical-grade hUC-MSCs with high expression levels of hematopoietic supporting factors were successfully cultured in an animal serum-free culture system.
Humans ; Mesenchymal Stem Cells/metabolism* ; Umbilical Cord/cytology* ; Cell Differentiation ; Female ; Cell Proliferation ; Cells, Cultured ; Chemokine CXCL12/metabolism* ; Angiopoietin-1/metabolism* ; Vascular Cell Adhesion Molecule-1/metabolism* ; Stem Cell Factor/metabolism* ; Flow Cytometry ; Pregnancy

BACKGROUND: Atrial fibrillation (AF) is a common cardiac arrhythmia in the elderly. This study aimed to evaluate urban-rural disparities in its prevalence and management in elderly Chinese. METHODS: Consecutive participants aged ≥ 65 years attending outpatient clinics were enrolled for AF screening using handheld single-lead electrocardiogram (ECG) from April 2017 to December 2022. Each ECG rhythm strip was reviewed from the research team. AF or uninterpretable single-lead ECGs were referred for 12-lead ECG. Primary study outcome comparison was between rural and urban areas for the prevalence of AF. The Student's t-test was used to compare mean values of clinical characteristics between rural and urban participants, while the Pearson's chi-square test was used to compare between-group proportions. Multivariate stepwise logistic regression analysis was performed to estimate the association between AF and various patient characteristics. RESULTS: The 29,166 study participants included 13,253 men (45.4%) and had a mean age of 72.2 years. The 7073 rural participants differed significantly (P ≤ 0.02) from the 22,093 urban participants in several major characteristics, such as older age, greater body mass index, and so on. The overall prevalence of AF was 4.6% (n = 1347). AF was more prevalent in 7073 rural participants than 22,093 urban participants (5.6% vs. 4.3%, P < 0.01), before and after adjustment for age, body mass index, blood pressure, pulse rate, cigarette smoking, alcohol consumption and prior medical history. Multivariate logistic regression analysis identified overweight/obesity (OR = 1.35, 95% CI: 1.17-1.54) in urban areas and cigarette smoking (OR = 1.62, 95% CI: 1.20-2.17) and alcohol consumption (OR = 1.42, 95% CI: 1.04-1.93) in rural areas as specific risk factors for prevalent AF. In patients with known AF in urban areas (n = 781) and rural areas (n = 338), 60.6% and 45.9%, respectively, received AF treatment (P < 0.01), and only 22.4% and 17.2%, respectively, received anticoagulation therapy (P = 0.05). CONCLUSIONS In China, there are urban-rural disparities in AF in the elderly, with a higher prevalence and worse management in rural areas than urban areas. Our study findings provide insight for health policymakers to consider urban-rural disparity in the prevention and treatment of AF.