1.The Histone Methyltransferase EZH2 is Downregulated in the Terminal Differentiation of Cardiomyocytes
Wan-Yi ZHANG ; Wan-Lei ZHANG ; Yuan-Yuan LIU ; Ling-Er DING ; Qi-Kai TANG ; Zhen-Hang LI ; Hao-Ying YANG ; Tao LI
Chinese Journal of Biochemistry and Molecular Biology 2025;41(3):415-425
Enhancer of zeste homolog 2(EZH2)is a histone methyltransferase It mediates trimethylation of lysine 27 on histone H3,thereby facilitating the epigenetic silencing of downstream genes.In conjunc-tion with SUZ12,EED,and other components,it constitutes the polycomb repressive complex 2(PRC2)complex.While EZH2 is intricately involved in cellular proliferation and cardiac development,the chan-ges in its expression during cardiac terminal differentiation remain elusive.In this study,we employed differential gene expression analysis of embryonic and adult myocardial cells using the GEO database,and found that EZH2 is highly expressed in embryonic myocardium,but is present at very low levels in adult myocardium(P<0.0001).Conversely,the expression changes of PRC2 members SUZ12 and EED are not as pronounced.Online analysis through the Tabula Muris database indicates that under physiological conditions,various cell subpopulations in the adult mouse heart exhibit negligible expression of EZH2.Immunohistochemical staining of mouse cardiac tissues shows that EZH2 is highly expressed in embryonic and neonatal myocardium but declines progressively from the first day after birth(P<0.0001),becoming almost undetectable by the third day.Western blotting further confirms the rapid disappearance of EZH2 expression post-birth(P<0.05),with EZH1 compensating for the downregulation of EZH2 to maintain H3K27me3 modification levels.Additionally,using the P19 teratocarcinoma stem cell model for cardio-myocyte differentiation,it is observed that EZH2 is significantly upregulated during the transition from cardiac progenitor cells to spontaneously beating cardiomyocytes,correlating with the expression of the cardiomyocyte transcription factor Gata4(P<0.01).Targeted degradation of EZH2 using the small mole-cule drug MS1943 significantly inhibits the proliferation of induced cardiomyocytes,as evidenced by 5-e-thynyl-2'-deoxyuridine(EdU)incorporation assays(P<0.01),and RT-qPCR reveals a marked in-crease in the expression of the proliferation inhibitor CDKN1A(P<0.01).In summary,the high expres-sion of EZH2 in embryonic myocardial cells is associated with enhanced cell proliferation.The rapid loss of EZH2 expression postnatally correlates with the loss of proliferative capacity in cardiomyocytes,mark-ing it as a key indicator of cardiac terminal differentiation.
2.Effects of Three AKT Isoform-specific Knockouts on Self-renewal and Differentiation in Mouse Embryonic Stem Cells
Qi YANG ; Shuai TANG ; Lin-Lin ZHANG ; Wu-Yang TANG ; Ao-Xiang DOU ; Yu-Hang ZHANG ; Pi-Shun LI ; Xiao-Feng ZHENG
Chinese Journal of Biochemistry and Molecular Biology 2025;41(3):426-436
AKT,also known as Protein Kinase B(PKB),plays a critical role in cell proliferation and metabolism.There are three isoforms of AKT:AKT1,AKT2,and AKT3.The effects of these isoforms on the pluripotency and differentiation of mouse embryonic stem cells(mESCs)remain unclear.This study aims to explore the impact of three AKT isoform-specific knockouts on the self-renewal and differen-tiation of mouse embryonic stem cells.Using CRISPR/Cas9 gene-editing technology,AKT isoform-spe-cific knockout cell lines were established.The phenotypic and molecular changes were analyzed through Western blotting,flow cytometry,qRT-PCR,CCK-8 assays,Alkaline Phosphatase(AP)staining,and RNA-seq.The construction of AKT isoform-specific knockout cell lines was successful.The loss of AKT1 and AKT2 inhibited the proliferation of mESCs.The knockout of any single AKT isoform did not affect the expression of pluripotency genes at both mRNA or protein levels.However,during embryoid body forma-tion,the deletion of any of the three AKT isoforms affected the mRNA expression levels of genes in all three germ layers.Transcriptome analysis showed that compared to wild-type mESCs,995,547,and 429 differentially expressed genes(|log2FC|≧1,P<0.05)were identified inAKT1,AKT2,and AKT3 isoform-specific knockout cells,respectively.There was some overlap in the differentially expressed genes regulated by these three isoforms.In conclusion,the independent knockout of AKT isoforms does not af-fect the maintenance of pluripotency in mouse embryonic stem cells,but they are crucial for differentia-tion.The three AKT isoforms can collectively regulate gene expression while retaining their own regulato-ry specificity.This study provides a foundation for understanding the unique and overlapping roles of AKT isoforms in stem cell biology,highlighting their importance in maintaining stem cell function and differen-tiation.
3.Treating Type 2 Diabetic Nephropathy by Down-regulating NOX4 to Inhibit the Oxidative Stress Pathway in Mesenchymal Stem Cells
Shu-Qi FENG ; Guo-Rong JIN ; Qun-Hang XUE ; Min HE ; Ze-Hang WANG ; Jia-Xin YAO ; Long CHEN ; Yu-Jiao WANG ; An-Xiu ZHANG ; Sheng HE ; Bing-Rui ZHOU ; Jun XIE
Chinese Journal of Biochemistry and Molecular Biology 2025;41(5):730-740
Diabetic nephropathy(DN)is a serious complication of diabetes mellitus and a leading cause of end-stage renal diseases.In DN patients,key pathological mechanisms include proteinuria,glomerulo-sclerosis,and fibrosis,largely driven by poor glycemic control and oxidative stress caused by prolonged hyperglycemia.This stress damages renal podocytes and triggers inflammatory mesenchymal infiltration of renal tubular cells,exacerbating the progression of proteinuria and fibrosis.Human umbilical cord-de-rived mesenchymal stem cells(hUC-MSCs)offer promising potential for treating DN due to their strong anti-oxidative properties.In this study,we developed a DN mouse model and treated the mouse via tail vein injections of hUC-MSCs(1×106 cells/mouse).The results indicated that hUC-MSCs significantly lowered fasting blood glucose levels(22.5±3.0 vs 14.7±1.1,P<0.01)and improved glucose toler-ance,as shown by intraperitoneal glucose tolerance test(IPGTT)results(P<0.05).Additionally,the renal function improved in hUC-MSCs-treated mice,with marked reductions in oxidative stress markers,including blood urea nitrogen(BUN),urinary creatinine(Ucr),urinary protein(PRO),superoxide dismutase(SOD),and malondialdehyde(MDA)(P<0.05).Histological analyses through hematoxy-lin-eosin(H&E),Periodic Acid-Schiff(PAS),and Sirius red staining demonstrated alleviation of glo-merular mesangial hyperplasia,glomerular hypertrophy,and tubular inflammation.Furthermore,hUC-MSCs treatment downregulated the expression of oxidative stress-related proteins,such as NADPH oxi-dase 4(NOX4)and thioredoxin-interacting protein(TXNIP),and reduced reactive oxygen species(ROS)production(P<0.05).Meanwhile,human renal cortical proximal tubule epithelial cells(HK-2 cells)were selected for validation in vitro experiments using high glucose treatment followed by super-natants of hUC-MSCs(MSC-CM),and Western blotting showed that the expression of both NOX4 and TXNIP was inhibited(P<0.05)and ROS expression was reduced.In conclusion,hUC-MSC treatment effectively lowered blood glucose levels and improved renal function in DN mice,likely through the sup-pression of NOX4 expression and TXNIP-mediated oxidative stress.
4.Role and mechanism of T helper 17 cells/regulatory T cells immune balance regulated by the TGF-β1/Smad signaling pathway mediated in nonalcoholic steatohepatitis
Qian WANG ; Kaiyang LI ; Mei YANG ; Hang ZHANG ; Shengjin ZHU ; Qi ZHAO ; Jing HUANG
Journal of Clinical Hepatology 2025;42(5):942-947
Nonalcoholic steatohepatitis(NASH)is a chronic metabolic disease characterized by hepatocyte fatty degeneration and ballooning degeneration,and it plays an important role in the progression of hepatic steatosis.Recent studies have shown that immune homeostasis imbalance between T helper 17(Th17)and regulatory T(Treg)cells are closely associated with the pathological process of NASH.Transforming growth factor-β1(TGF-β1)is a key cytokine for regulating the differentiation and proliferation of Th17/Treg cells,and TGF-β1 binds to its receptor and activates the Smad signaling pathway,thereby regulating the immune balance of Th17/Treg cells and the expression of inflammatory factors and participating in the repair of liver inflammation.This article systematically reviews the molecular mechanism of the TGF-β1/Smad signaling pathway in affecting NASH by regulating the immune balance of Th17/Treg cells,in order to provide a theoretical basis for the research on the pathogenesis of NASH and related treatment strategies.
5.Improvement effects of fecal microbiota transplantation on chemotherapy-induced diarrhea in mice
Qiu-Yu YANG ; Meng-Tian TAN ; Jing BAI ; Xing REN ; Jun-Qi ZHANG ; Yong YANG ; Yu-Hang SUN ; Lei LI ; Ze-Xian FU
Medical Journal of Chinese People's Liberation Army 2025;50(3):261-268
Objective To investigate the improvement effects of homogeneous fecal microbiota transplantation(FMT)on chemotherapy-induced diarrhea(CID)in mice.Methods Fifteen C57BL/6N mice were divided into control group,CID model group and CID+FMT group according to the random number distribution and remainder grouping method,with 5 mice per group.Control group received no intervention,and their feces were used to prepare fecal bacteria suspension.CID model group was injected intraperitoneally with fluorouracil(65 mg/kg)for 5 consecutive days to construct the CID mouse model,followed by gavage with 0.1 ml of saline on alternate days.CID+FMT group was given 0.1 ml fecal bacteria suspension gavage on alternate days for one week,followed by intraperitoneal injection of fluorouracil(65 mg/kg)for 5 consecutive days to construct the CID mouse model,with the experiment ending on the 14th day.During the experiment,the mice's food intake and body weight were recorded.At the end of the experiment,the mice were euthanized with deep carbon dioxide anesthesia,and the mice colonic specimens from cecum to anus were collected for hematoxylin and eosin(HE)staining and histopathological examination.Fecal samples were collected for 16S rRNA gene sequencing.Shannon index,Simpson index and Chao1 algorithm were used to analyze the α-diversity species of the intestinal flora in each group of mice.Similarity analysis(Anosim)was used to perform non-parametric on the inter-group differences of intestinal flora among the mice.Linear discriminate analysis size effect(LEfSe)and nonmetric multidimensional scaling(NMDS)were employed to analyze the intestinal dominant flora and the similarity classification relationships in each group of mice.Results The colonic specimen's length from cecum to anus in CID model group was significantly shorter than that in control group(P<0.05),while there was no significant difference between CID+FMT group and CID model group(P>0.05).The weight of mice in CID model group decreased by 42.04%,while control group mice gained 10.24%,with a significant difference between the two groups(P<0.05).The weight of mice in CID+FMT group decreased by 8.12%,which was significantly improved compared to CID model group(P<0.05).HE staining results revealed the intestinal mucosal structure in CID model group was severely damaged,with atrophy and deformation,accompanied by inflammatory cell infiltration,and the pathological score was higher than that of control group(P<0.05).Compared with CID model group,the intestinal mucosal integrity and crypt cells in the CID+FMT group were improved,with less damage,and the pathological score was lower than that of CID model group,but the difference was not statistically significant(P>0.05).The α-diversity analysis showed that there were significant differences in the Shannon,Simpson and Chao1 indices among the three groups(P<0.05).ANOSIM and NMDS analysis revealed that the intestinal flora in CID+FMT group was closer to the normal intestinal flora compared to CID model group.LEfSe analysis showed that the intestinal flora in CID model group was enriched in famliy_Bacteroidaceae,and the intestinal flora in CID+FMT group was similar to that of control group,with an enrichenment of familiy_Enterobacteriaceae.Conclusion Homogeneous FMT can improve the abundance of intestinal flora in CID mice,making it more similar to normal intestinal flora,thereby protecting intestinal mucosa,reducing damage and alleviating the severity of CID.
6.Design and Implementation of Non-Invasive Hemodynamic Monitoring System Based on Impedance Cardiogram Method.
Fuhao KANG ; Qi YIN ; Yanan LIU ; Lin HUANG ; Yan HANG ; Jilun YE ; Xu ZHANG
Chinese Journal of Medical Instrumentation 2025;49(1):80-88
Hemodynamic monitoring can reflect cardiac function and blood perfusion and is an indispensable monitoring method in clinical practice. Invasive hemodynamic monitoring methods represented by the thermodilution method are limited in their clinical application scope because they require vascular cannulation. Non-invasive hemodynamic monitoring has attracted extensive attention from medical companies and clinicians at home and abroad in recent years due to its advantages such as safety, non-invasiveness, continuous monitoring, simple operation, and low cost. This paper designs a non-invasive hemodynamic monitoring system based on the impedance cardiography, including hardware, algorithm, software design, and performance parameter evaluation. Among them, the hardware part mainly includes a differential high-frequency constant current source stimulation circuit, impedance cardiogram signal acquisition, and ECG signal acquisition circuit. Signal processing includes wave filtering, impedance cardiogram signal calibration, and ECG signal and impedance cardiogram signal feature point recognition. According to the collected impedance cardiogram and ECG signals, hemodynamic parameters such as heart rate (HR), stroke volume (SV), cardiac output (CO), stroke index (SI), cardiac index (CI), and cardiac contractility index (ICON) are calculated based on the Nyboer thoracic cylinder model. After testing, the key technical indicators of the system hardware are better than that of the relevant medical device standards. The system was used to collect impedance cardiogram and ECG signal data from 40 volunteers. The calculated HR, SV, and CO, three important hemodynamic indicators, were compared with the ICONCore non-invasive cardiac output monitor of OSYPKA Medical in Germany. Their Pearson correlation coefficients were 0.992 ( P<0.001), 0.948 ( P<0.001), and 0.933 ( P<0.001), respectively, verifying that the designed system has high accuracy and reliability.
Cardiography, Impedance/methods*
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Humans
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Hemodynamic Monitoring/methods*
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Equipment Design
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Signal Processing, Computer-Assisted
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Hemodynamics
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Algorithms
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Monitoring, Physiologic/methods*
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Electrocardiography
7.Development of a Microstream End-Tidal Carbon Dioxide Monitoring System with Integrated Gas Circuit.
Yanan LIU ; Xuedong SONG ; Qi YIN ; Fuhao KANG ; Yan HANG ; Jilun YE ; Xu ZHANG
Chinese Journal of Medical Instrumentation 2025;49(2):204-211
End-tidal carbon dioxide monitoring is an important means of evaluating human lung function and is widely used in fields such as clinical emergency treatment and cardiopulmonary resuscitation. This paper develops a microstream end-tidal carbon dioxide monitoring system. It adopts an integrated gas circuit design to further reduce the size of the equipment. The system uses the method of calculating the root mean square (RMS) of differential pressure signals to regulate the gas circuit flow, enabling the system to stably operate at a flow state of 30 mL/min. In addition, by simultaneously detecting multiple environmental parameters such as temperature and pressure, the system realizes system state monitoring and gas parameter compensation. The test results show that various indicators of the system meet the requirements of relevant standards, laying a good foundation for subsequent engineering applications.
Carbon Dioxide/analysis*
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Equipment Design
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Monitoring, Physiologic/methods*
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Humans
8.Development of a Multimodal Transcranial Electrical Stimulation System with Integrated Four-Channel EEG Recordings.
Yan HANG ; Chaoyang WANG ; Qi YIN ; Yanan LIU ; Lin HUANG ; Jilun YE ; Xu ZHANG
Chinese Journal of Medical Instrumentation 2025;49(3):313-322
In order to improve the effect of transcranial electrical stimulation treatment and realize personalized treatment for patients with varying severity levels, this paper designed an integrated four-channel EEG recording multimodal transcranial electrical stimulation system. This system can conduct real-time monitoring on EEG and related characteristic analysis before stimulation, in stimulation, and after stimulation. This enables physicians and researchers to resolve real-time brain states, evaluate transcranial electrical stimulation effect, and then artificially adjust the stimulation parameters. After relevant testing and verification, the system can select four stimulation modes: TACS, TDCS, TPCS and TRNS, which can output the constant stimulation current of 0.03 mA accuracy in the range of ±2 mA and the stimulation frequency of low frequency of 0~4 kHz (precision of 0.01 Hz) and high frequency 50~100 kHz, which can obtain more accurate EEG signals under stimulation interference, demonstrating a good market application prospect.
Electroencephalography/methods*
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Transcranial Direct Current Stimulation/instrumentation*
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Humans
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Equipment Design
9.Sixteen-Channel Multimodal High-Precision Transcranial Electrical Stimulation System Development.
Yan HANG ; Qi YIN ; Lin HUANG ; Fuhao KANG ; Yanan LIU ; Jilun YE ; Xu ZHANG
Chinese Journal of Medical Instrumentation 2025;49(4):435-443
This paper introduces a 16-channel multimodal high-precision transcranial electrical stimulation system specifically for non-invasive brain stimulation. This system added TMCS mixed four traditional stimulation modes with TACS, TDCS, TPCS and TRNS. By designing a compensated high-precision constant current source, the constant stimulation current with an accuracy of 0.03 mA in the range of ±2 mA and the stimulation frequency of 50~200 kHz with low frequency of 0~4 kHz (high frequency of 0.1 Hz) are realized. In TACS stimulation mode, there are five adjustable wave forms: triangular wave, sine wave, sawtooth wave, square wave and mixed wave. The system has dual closed-loop control overcurrent detection and simultaneous real-time electrode contact impedance detection. After relevant tests and verification, the system has good stimulation accuracy, high safety and reliability. Compared with the existing products at home and abroad, it features lower cost, richer stimulation mode and waveforms, demonstrating a certain market application value.
Transcranial Direct Current Stimulation/instrumentation*
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Equipment Design
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Humans
10.USP51/GRP78/ABCB1 axis confers chemoresistance through decreasing doxorubicin accumulation in triple-negative breast cancer cells.
Yang OU ; Kun ZHANG ; Qiuying SHUAI ; Chenyang WANG ; Huayu HU ; Lixia CAO ; Chunchun QI ; Min GUO ; Zhaoxian LI ; Jie SHI ; Yuxin LIU ; Siyu ZUO ; Xiao CHEN ; Yanjing WANG ; Mengdan FENG ; Hang WANG ; Peiqing SUN ; Yi SHI ; Guang YANG ; Shuang YANG
Acta Pharmaceutica Sinica B 2025;15(5):2593-2611
Recent studies have indicated that the expression of ubiquitin-specific protease 51 (USP51), a novel deubiquitinating enzyme (DUB) that mediates protein degradation as part of the ubiquitin‒proteasome system (UPS), is associated with tumor progression and therapeutic resistance in multiple malignancies. However, the underlying mechanisms and signaling networks involved in USP51-mediated regulation of malignant phenotypes remain largely unknown. The present study provides evidence of USP51's functions as the prominent DUB in chemoresistant triple-negative breast cancer (TNBC) cells. At the molecular level, ectopic expression of USP51 stabilized the 78 kDa Glucose-Regulated Protein (GRP78) protein through deubiquitination, thereby increasing its expression and localization on the cell surface. Furthermore, the upregulation of cell surface GRP78 increased the activity of ATP binding cassette subfamily B member 1 (ABCB1), the main efflux pump of doxorubicin (DOX), ultimately decreasing its accumulation in TNBC cells and promoting the development of drug resistance both in vitro and in vivo. Clinically, we found significant correlations among USP51, GRP78, and ABCB1 expression in TNBC patients with chemoresistance. Elevated USP51, GRP78, and ABCB1 levels were also strongly associated with a poor patient prognosis. Importantly, we revealed an alternative intervention for specific pharmacological targeting of USP51 for TNBC cell chemosensitization. In conclusion, these findings collectively indicate that the USP51/GRP78/ABCB1 network is a key contributor to the malignant progression and chemotherapeutic resistance of TNBC cells, underscoring the pivotal role of USP51 as a novel therapeutic target for cancer management.

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