BACKGROUND:Rev-erbα is involved in the regulation of inflammation,but pharmacological activation of Rev-erbα increases the risk for cardiovascular diseases.To reduce the relevant risk,an exploration on SR9009,a Rev-erbα agonist,combined with other drugs to relieve inflammation in skeletal myoblasts was conducted,laying the theoretical foundation for the treatment of inflammation-associated skeletal muscle atrophy. OBJECTIVE:To investigate the relationship of SR9009,indolepropionic acid and nuclear factor-κB signaling pathways in lipopolysaccharide-induced C2C12 myoblasts. METHODS:(1)C2C12 myoblasts were induced to differentiate in the presence of lipopolysaccharide(1 μg/mL).RNA-seq and KEGG pathway analysis were used to study signaling pathways.(2)C2C12 myoblast viability was assessed using the cell counting kit-8 assay to determine optimal concentrations of indolepropionic acid.Subsequently,cells were categorized into control group,lipopolysaccharide(1 μg/mL)group,SR9009(10 μmol/L)+lipopolysaccharide group,indolepropionic acid(80μmol/L)+lipopolysaccharide group,and SR9009+indolepropionic acid+lipopolysaccharide group.ELISA was employed to measure protein expression levels of interleukin-6 in the cultured supernatant.Real-time quantitative PCR were employed to measure mRNA expression levels of interleukin-6,tumor necrosis factor α,TLR4 and CD14.Western blot assay were employed to measure protein expression levels of NF-κB p65 and p-NF-κB p65.(3)After Rev-erbα was knocked down by siRNA,knockdown efficiency was assessed by RT-qPCR.And mRNA levels of interleukin-6 and tumor necrosis factor α were also measured. RESULTS AND CONCLUSION:Compared with the blank control group,lipopolysaccharide time-dependently inhibited myofibroblast fusion to form myotubes,the mRNA expression levels of interleukin-6 and tumor necrosis factor α were elevated,and the level of interleukin-6 in the cell supernatant was significantly increased.The results of KEGG pathway showed that the nuclear factor-κB signaling pathway was activated by lipopolysaccharide.Indolepropionic acid exhibited significant suppression of C2C12 myoblasts viability when its concentration exceeded 80 μmol/L.Indolepropionic acid and SR9009 inhibited the activation of NF-κB signaling pathway,thereby played an anti-inflammatory role,and suppressed the mRNA expression levels of interleukin-6,tumor necrosis factor α,TLR4 and CD14.Compared with the lipopolysaccharide group,the ratio of p-NF-κB p65/NF-κB p65 protein expression were downregulated.SR9009 combined with indolepropionic acid notably reduced lipopolysaccharide-induced inflammation,further downregulated the mRNA expression levels of interleukin-6,tumor necrosis factor α,TLR4 and CD14.The ratio of p-NF-κB p65/NF-κB p65 protein expression was significantly lower than that in the SR9009+lipopolysaccharide group or indolepropionic acid+lipopolysaccharide group.Rev-erbα increases time-dependently with lipopolysaccharide induction.The knockdown efficiency of Rev-erbα by siRNA reached over 58%,and lipopolysaccharide was added after Rev-erbα was successfully knocked down.Compared with the lipopolysaccharide group,the mRNA expression levels of interleukin-6 and tumor necrosis factor α were significantly up-regulated.These results conclude that Rev-erbα may act as a promising pharmacological target to reduce inflammation.SR9009 targeted activation of Rev-erbα combined with indolepropionic acid significantly inhibits the nuclear factor-κB signaling pathway and attenuates the inflammatory response of C2C12 myofibroblasts.Moreover,the combined anti-inflammatory effect is superior to that of the intervention alone.

ObjectiveTo establish a quality evaluation method for Zhuye Shigao granules（Zhuye Shigaotang） based on fingerprint and determination of index components， and to investigate the therapeutic effect of Zhuye Shigao granules on mice with cold-dampness pestilence attacking lung syndrome. MethodsThe fingerprint of Zhuye Shigao granules was established by high performance liquid chromatography（HPLC）， and the methods for determination of total calcium， orientin， isoorientin， ginsenosides Rg₁， Re and Rb₁ and other 2 index components were established. Fifty ICR mice were randomly divided into the blank group， model group， Zhuye Shigao granules low， medium and high dose groups（9.3， 18.6， 37.2 g·kg^-1·d^-1）， with 10 mice in each group. In addition to the blank group， the model mice with cold-dampness pestilence attacking lung syndrome was prepared by nasal drip of lipopolysaccharide combined with cold-dampness environment. Each administration group was given the corresponding liquid by gavage according to the dose， while the blank group and model group were given the same volume of normal saline by gavage. Then， the body temperature and organ index of mice in each group were measured， hematoxylin-eosin（HE） staining was used to investigate the lung tissue injury of mice in each group， and enzyme-linked immunosorbent assay（ELISA） was used to detect the changes of tumor necrosis factor-α（TNF-α）， interleukin（IL）-lβ， IL-6， IL-10 levels in serum and lung tissue， as well as immunoglobulin（Ig）A and IgM levels in serum. ResultsThe fingerprint similarity of 10 batches of Zhuye Shigao granules was>0.950， and 20 common peaks were calibrated. Seven of them were identified， including peak 11（isoorientin）， peak 12（orientin）， peak 14（apioside liquiritin）， peak 15（liquiritin）， peak 17（apioside isoliquiritin）， peak 19（isoliquiritin） and peak 20（liquiritigenin）. The results of quantitative analysis showed that the content range of each index component in 10 batches of Zhuye Shigao granules was as follows：Total calcium of 9.978-11.294 mg·g^-1， isoorientin of 0.033-0.041 mg·g^-1， orientin of 0.046-0.055 mg·g^-1， ginsenoside Rg₁+ginsenoside Re of 0.748-0.762 mg·g^-1， ginsenoside Rb₁ of 0.151-0.197 mg·g^-1， liquiritin of 1.106-1.366 mg·g^-1， glycyrrhizic acid of 0.904-1.182 mg·g^-1_. Compared with the blank group， the body temperature of mice in the model group was significantly increased， the organ indexes of liver， lung and spleen were significantly decreased， the organ index of thymus was significantly increased， HE staining of lung tissue showed infiltration of inflammatory cells， a small amount of serous exudation was observed in the alveoli， and lung tissue was damaged. After the intervention of Zhuye Shigao granules， the pathological changes were improved compared with the model group. The expression levels of IL-1β， IL-6 and TNF-α were significantly increased， the expression level of IL-10 was significantly decreased in serum and lung tissue. The levels of IgA and IgM in serum were significantly decreased（P<0.01）. Compared with the model group， the body temperature， the organ indexes and immune factor levels in serum and lung tissue of mice in the Zhuye Shigao granules medium and high dose groups were significantly reduced（P<0.05， P<0.01）. ConclusionIn this study， the quality evaluation of Zhuye Shigao granules was carried out based on fingerprint combined with determination of index components， and the fingerprint of four herbs（Lophatheri Herba， Ophiopogonis Radix， Pinelliae Rhizoma and Glycyrrhizae Radix et Rhizoma） in this formula and the determination of 8 index components were established. The therapeutic effect of Zhuye Shigao granules on mice with cold-dampness pestilence attacking lung syndrome may be related to inhibiting inflammatory response and mediating immune regulation.

Background Di(2-ethylhexyl) phthalate (DEHP) is the most prevalent environmental endocrine disruptor among phthalate acid esters (PAEs) worldwide. Previous studies have indicated that exposure to DEHP may disrupt glucose metabolism. Objective To investigate the impact of DEHP on glucose homeostasis in rats, focusing on oxidative stress-induced impairment of autophagy in islet β cells. Methods Forty male SD rats were randomly assigned to four groups, receiving DEHP doses of 0, 187, 375, and 750 mg·kg⁻¹ for 12 weeks. Oral glucose tolerance (OGTT) and insulin tolerance tests (ITT) were conducted 24 h after the final exposure. Pancreatic microstructural alterations were assessed using hematoxylin and eosin (HE) staining and transmission electron microscopy (TEM). Commercial ELISA kits were employed to quantify the levels of insulin, adenosine triphosphate (ATP), and adenosine monophosphate (AMP) in rat serum, as well as the protein expression level of activated caspase-3 in pancreatic tissue. Additionally, commercial microplate kits were utilized to measure the concentration of reduced glutathione (GSH) in serum, the activity of superoxide dismutase (SOD) using water-soluble tetrazolium salt-1, the content of malondialdehyde (MDA) by thiobarbituric acid method, and the level of reactive oxygen species (ROS) in pancreatic tissue by chemical fluorescence method. Reverse transcription polymerase chain reaction (RT-PCR) was used to measure sequestosome1 (SQSTM1/p62), Beclin1, microtubule-associated protein 1 light chain 3 (LC3), and cysteinyl aspartate specific proteinase-8 (Caspase-8) mRNA levels. Western blot analysis was applied to detect the protein relative expression levels of p62, Beclin-1, LC3-I, LC3 II, AMPK, p-AMPK, mTOR, p-mTOR, ULK1, and Caspase-8. Results Compared to the 0 mg·kg⁻¹ DEHP group, the 750 mg·kg⁻¹ DEHP group exhibited a significant increase in fasting blood glucose levels at 2, 4, 6, and 12 weeks (P<0.05). The OGTT showed that, following high-glucose gavage, the 187 mg·kg⁻¹ DEHP group had elevated blood glucose at 30 min (P<0.05), the 375 mg·kg⁻¹ DEHP group showed increased glucose levels at 15, 30, and 180 min (P<0.05), and the 750 mg·kg⁻¹ DEHP group exhibited elevated levels at 15, 30, 60, and 180 min (P<0.05). The 375 and 750 mg·kg⁻¹ DEHP groups demonstrated significantly increased OGTT area under the curve (AUC) values (P<0.05). In contrast, ITT results indicated no significant differences in blood glucose levels or AUC among the DEHP exposure groups at all time points (P>0.05). Compared to the 0 mg·kg⁻¹ DEHP group, the 750 mg·kg⁻¹ DEHP group exhibited significantly higher HOMA-IR levels and markedly lower HOMA-ISI values (P<0.05). HE and TEM showed that in each DEHP exposure group, the number of islet cells decreased, the islet area reduced, and chromatin condensation occurred. The endocrine granules in the cytoplasm of islet β cells decreased, and there were varying degrees of widening of the nuclear membrane gap, flattening and expansion of the Golgi complex, and expansion of the endoplasmic reticulum. Ribosome separation was observed, and autophagosomes were visible. In the 375 and 750 mg·kg⁻¹ DEHP groups, the mitochondria were deformed to varying degrees, and some cristae structures disappeared, presenting vacuolization. Moreover, the chromatin condensation in the nuclei was more severe in the 750 mg·kg⁻¹ DEHP group. The serum SOD activity was significantly elevated in the 750 mg·kg⁻¹ DEHP group (P<0.05). Both the 375 mg·kg⁻¹ and 750 mg·kg⁻¹ DEHP groups exhibited a significant increase in the relative ROS content in pancreatic tissue (P<0.05). In DEHP-treated groups, the MDA content increased (P<0.05), while the GSH content decreased (P<0.05). Additionally, in the 750 mg·kg⁻¹ DEHP group, the AMP/ATP ratio in serum was significantly raised (P<0.05), and the expression of cleaved Caspase-3 protein in pancreatic tissue was also significantly increased (P<0.05). The relative mRNA levels of p62, Beclin-1, LC3, and Caspase-8 in the pancreatic tissue of rats exposed to DEHP were significantly elevated (P<0.05). The relative expression levels of p-AMPK/AMPK, p-ULK1/ULK1, and Beclin-1 proteins in the DEHP-treated groups were significantly increased (P<0.05). In the 375 mg·kg⁻¹ and 750 mg·kg⁻¹ DEHP treatment groups, the relative expression levels of p62, LC3 II/LC1, and Caspase-8 proteins were significantly increased (P<0.05), while the relative expression level of p-mTOR/mTOR was significantly decreased (P<0.05). Conclusion DEHP can disrupt glucose homeostasis by inducing oxidative stress, which subsequently activates autophagy via the ROS/AMPK/ULK1 pathway, impairing autophagic flux and promoting apoptosis of islet β cells, ultimately decreasing their function and number.

Objective To analyze the nonlinear relationship between hypothermic machine perfusion (HMP) parameters and delayed graft function (DGF) and optimize the construction of a predictive model for DGF. Methods The data of 923 recipients who underwent kidney transplantation from deceased donors were retrospectively analyzed. According to the occurrence of DGF, the recipients were divided into DGF group (n=823) and non-DGF group (n=100). Donor data, HMP parameters and recipient data were analyzed for both groups. The nonlinear relationship between HMP parameters and the occurrence of DGF was explored based on restricted cubic splines (RCS). Over-sampling, under-sampling and balanced sampling were used to address the imbalance in the proportion of DGF to construct logistic regression predictive models. The area under the curve (AUC) of each model was compared in the validation set, and a nomogram model was constructed. Results Donor BMI, cold ischemia time of the donor kidney, and HMP parameters (initial and final pressures, resistance, and perfusion time) were significantly different between the DGF and non-DGF groups (all P<0.05). The RCS analysis revealed a threshold-like nonlinear relationship between HMP parameters and the risk of DGF. Among the models constructed using different sampling methods, the balanced sampling model had the highest AUC. Using this model, a nomogram was constructed to stratify recipients based on risk scores. Recipients in the high-risk group had higher serum creatinine levels at 1, 6, and 12 months after kidney transplantation compared to those in the low-risk group (all P<0.05). Conclusions There is a nonlinear relationship between HMP parameters and the risk of DGF, and the threshold is helpful for organ quality assessment and monitoring of graft function after transplantation. The predictive model for DGF constructed on the base of balanced sampling algorithms helps perioperative decision-making and postoperative graft function monitoring of kidney transplantation.

ObjectiveTo clarify the neuroprotective effect of black Panacis Quinquefolii Radix（PQR） and explore its active ingredients， with the aim of establishing an activity-oriented quality evaluation method. MethodsTransgenic Tg（HuC∶EGFP） zebrafish was used to establish a neuronal injury model by aluminum chloride immersion. Different doses（10， 20 mg·L^-1） of PQR and black PQR ethanol extracts were administered. The neuroprotective effects of PQR and black PQR were compared by analyzing the fluorescent area and intensity of zebrafish neurons. Based on ultra-performance liquid chromatography（UPLC）， a fingerprint profile of black PQR was established， followed by principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA）. Differential components were screened using the criteria of variable importance in the projection（VIP） value>1 and P<0.05. The neuroprotective activity of 14 batches of black PQR was assessed， and Spearman correlation analysis was used to identify saponins related to neuroprotective activity， which were then validated. Based on the above results， active marker components were determined， and an UPLC method was established for their quantitation with clear content limits. ResultsPharmacological efficacy results showed that both PQR and black PQR at different doses could significantly improved neuronal damage in zebrafish. At a dose of 20 mg·L^-1， black PQR demonstrated superior efficacy（P<0.05）. The fingerprint similarities of 14 batches of black PQR were>0.94， with 26 common peaks identified. Through comparison with the reference standards， 8 components were confirmed， including peak 1（ginsenoside Rg₁）， peak 2（ginsenoside Re）， peak 5（ginsenoside Rb₁）， peak 9（ginsenoside Rd）， peak 16［ginsenoside 20（S）-Rg₃］， peak 17［ginsenoside 20（R）-Rg₃］， peak 18（ginsenoside Rk₁）， and peak 19（ginsenoside Rg₅）. The results of PCA and OPLS-DA indicated that there were differences in saponins among black PQR samples from different origins， and 12 differential components were screened. All 14 batches of black PQR exhibited good protective effects on zebrafish neurons， with Shaanxi-produced black PQR showing superior protective effects compared to the other three production regions. Spearman correlation analysis revealed that a total of 11 components， including ginsenosides 20（S）-Rg₃， 20（R）-Rg₃， Rk₁ and Rg₅， showed a significant positive correlation with the neuroprotective effect in zebrafish（P<0.05）. The activity validation results indicated that ginsenosides 20（S）-Rg₃， 20（R）-Rg₃， Rk₁ and Rg₅ were the primary components responsible for the neuroprotective effects of black PQR. Quantitative analysis showed that the content of ginsenoside 20（S）-Rg₃ in 14 batches of black PQR ranged from 0.17% to 0.52%， and the repair rate of neuronal damage ranged from 42.77% to 97.83%. ConclusionBased on the fingerprint and neuronal protective activity， the spectrum-effect related quality control model of black PQR was established， with ginsenoside 20（S）-Rg₃ as the quality control index， and the neuronal damage repair rate≥60% as the evaluation standard， the minimum limit of ginsenoside 20（S）-Rg₃ in black PQR should be≥0.20%.

ObjectiveTo assess the quality consistency of black Panacis Quinquefolii Radix（bPQR） decoction pieces prepared by atmospheric and pressurized steaming processes based on chromaticity-chemical composition-vasoactive inhibition. The ultimate goal was to screen the pressurized steaming process yielding quality equivalent to atmospheric steaming， and optimize the processing technology of bPQR. MethodsThe bPQR decoction pieces were prepared using both atmospheric and pressurized steaming processes， and the chromaticity values［lightness value（L^*）， red/green chromaticity value（a^*）， yellow/blue chromaticity value（b^*）， total chromaticity value（E^*ab）］ were measured. High performance liquid chromatography（HPLC） was employed to establish fingerprint profiles for the decoction pieces， and cluster analysis was conducted on chromaticity values and the common peak areas in fingerprint profiles to elucidate the quality relationships between the decoction pieces processed by different methods. The optimal atmospheric steaming of bPQR decoction pieces was determined through zebrafish angiogenesis inhibition experiments. The contents of ginsenosides Rg₁， Re， Rb₁， 20（S）-Rg₃， Rk₁ and Rg₅ in the decoction pieces were quantified， and Spearman correlation analysis was employed to investigate the relationship between saponin content， chromaticity， and angiogenesis inhibition activity during the steaming process. By integrating the consistency of chromaticity， saponin components and angiogenesis inhibition activity， pressurized steaming conditions with quality equivalent to the atmospheric pressure method were selected. ResultsCompared with the atmospheric steaming method， pressurized steaming resulted in faster color darkening and higher conversion rates of ginsenosides in bPQR decoction pieces. Moreover， the neovascularization inhibitory activity of bPQR decoction pieces continued to increase with the deepening of processing. Based on the effectiveness and safety， the optimal process for preparing bPQR decoction pieces with neovascularization inhibitory activity was determined to be atmospheric steaming for 21 h. All six ginsenosides tested exhibited strong to extremely strong correlations with both the chromaticity values of the decoction pieces and their neovascularization inhibitory activities. Among them， ginsenosides Rg₁， Re and Rb₁ exhibited positive correlations with chromaticity values and negative correlations with zebrafish angiogenesis inhibition activity. Conversely， ginsenosides 20（S）-Rg₃， Rk₁ and Rg₅ showed negative correlations with chromaticity values and positive correlations with zebrafish angiogenesis inhibition activity. By integrating chromaticity values， cluster analysis results， as well as the results of activity， it was determined that the quality of bPQR decoction pieces steamed under pressurized conditions of 110 ℃（0.045 MPa） for 5 h and 115 ℃（0.07 MPa） for 3 h was highly consistent with that obtained by atmospheric steaming for 21 h. ConclusionThe preparation of bPQR decoction pieces by pressurized steaming has the advantages of short preparation time， low energy consumption， and rapid saponin conversion rate， making it a viable alternative to atmospheric steaming for preparing bPQR decoction pieces. Meanwhile， the evaluation method based on chromaticity-chemical composition-activity can provide a more scientific and effective explanation of change rules in the quality during traditional Chinese medicine processing， and offer a new model for optimizing processing technology and enhancing quality control.

ObjectiveThe U6 promoter is an essential element for driving sgRNA expression in the clustered regularly interspaced short palindromic repeat sequences/CRISPR-associated protein 9（CRISPR/Cas9）gene editing system in dicotyledonous plants. Endogenous U6 promoters typically exhibit higher transcriptional activity， which can significantly improve gene editing efficiency. This study aims to identify endogenous U6 promoters in Artemisia annua to optimize its CRISPR/Cas9 gene editing system， which holds significant importance for its molecular breeding. MethodsOn the basis of the highly conserved U6 snRNA sequences in Arabidopsis thaliana， endogenous U6 promoters were screened in the A. annua genome. Expression vectors were constructed with candidate AaU6 promoter driving the firefly luciferase （LUC） reporter gene， and then transiently transformed into Nicotiana benthamiana. Transcriptional activities of the promoters were measured and compared by in vivo imaging and the Dual Luciferase Reporter assay. ResultsEight endogenous U6 promoters were successfully cloned from A. annua. Sequences alignment revealed that all these promoters contained the two conserved cis-acting elements， upstream sequence element （USE） and TATA-box， which affected their transcriptional activity. Dual-luciferase activity assays indicated that the transcriptional activities of AaU6-3， AaU6-1， and AaU6-5 were significantly higher than that of the Arabidopsis AtU6-26 promoter， with AaU6-3 exhibiting the highest activity. ConclusionThis study identified three endogenous AaU6 promoters with high transcriptional activity in A. annua， providing key functional elements for establishing an efficient gene editing system in A. annua. These findings will contribute to advancing precision molecular breeding and high-quality germplasm innovation in A. annua.

BACKGROUND: Whether adherence to a healthy lifestyle is associated with a lower risk of developing pneumonia and a better long-term prognosis remains unclear. This study aimed to investigate associations of individual and combined lifestyle factors (LFs) with the incidence risk and long-term prognosis of pneumonia hospitalization. METHODS: Using data from the China Kadoorie Biobank study, we used the multistate models to investigate the role of five high-risk LFs, including smoking, excessive alcohol drinking, unhealthy dietary habits, physical inactivity, and unhealthy body shape, alone or in combination in the transitions from a generally healthy state at baseline to pneumonia hospitalization or cardiovascular disease (CVD, regarded as a reference outcome), and subsequently to mortality. RESULTS: Most of the five high-risk LFs were associated with increased risks of transitions from baseline to pneumonia and from pneumonia to death, but with different risk estimates. The greater the number of high-risk LFs, the higher the risk of developing pneumonia and long-term mortality risk after pneumonia, with the strength of associations comparable to that of LFs and CVD. Compared to participants with 0-1 high-risk LF, the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for transitions from baseline to pneumonia and from pneumonia to death in those with five high-risk LFs were 1.43 (1.28-1.60) and 1.98 (1.61-2.42), respectively. Correspondingly, the respective HRs (95% CIs) for transitions from baseline to CVD and from CVD to death were 2.00 (1.89-2.11) and 1.44 (1.30-1.59), respectively. The risk estimates changed slightly when further adjusting for the presence of major chronic diseases. CONCLUSION In this Chinese population, unhealthy LFs were associated with an increased incidence and long-term mortality risk of pneumonia.
Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Cardiovascular Diseases/etiology* ; China/epidemiology* ; Life Style ; Pneumonia/etiology* ; Prognosis ; Risk Factors ; Smoking

BACKGROUND: Metabolic-associated fatty liver disease (MAFLD) is a common liver disease and may become the leading cause of severe liver disease in the future. The Global Burden of Disease (GBD) study assesses MAFLD's impact in countries and regions worldwide, providing insights into its prevalence. METHODS: Prevalence data for MAFLD from 1990 to 2021 by country and region in all sex and age groups were collected from the Global Health Data Exchange. The categorization of countries and geographic areas by development was performed using the Sociodemographic Index (SDI). RESULTS: Between 1990 and 2021, the global crude prevalence rate of MAFLD increased from 10.6% to 16.1% (beta-coefficient: 0.2%, 95% confidence interval [CI]: 0.2-0.2%, P  <0.001), and the age-standardized prevalence rate was increased from 12.1% to 15.0% (beta-coefficient: 0.1%, 95% CI: 0.1-0.1%, P  <0.001). In 2021, MAFLD was estimated to have affected 1.3 billion people worldwide. Significant uptrends were observed in all regions, super regions, and SDI categories. The fastest increase from 1990 to 2021 and the highest prevalence rate in 2021 were experienced by countries and territories with high-middle and middle SDI. An increase in the prevalence of MAFLD from 1990 to 2021 was demonstrated in all but six countries. CONCLUSIONS In 2021, the number of patients affected by MAFLD was doubled compared to 1990, and the prevalence rate increased by over 50%. The burden of MAFLD, as measured by prevalence, was more prominent in countries and territories with middle SDI and in those located in North African and Middle Eastern, possibly due to changes in lifestyle in these areas over the past 30 years.
Humans ; Global Burden of Disease ; Prevalence ; Male ; Female ; Middle Aged ; Adult ; Global Health ; Fatty Liver/epidemiology* ; Aged

OBJECTIVES: Bladder cancer is a common malignancy with high incidence and poor prognosis. N⁶-methyladenosine (m⁶A) modification is widely involved in diverse physiological processes, among which the m⁶A recognition protein YTH N⁶-methyladenosine RNA binding protein F2 (YTHDF2) plays a crucial role in bladder cancer progression. This study aims to elucidate the molecular mechanism by which O-linked N-acetylglucosamine (O-GlcNAc) modification of YTHDF2 regulates its downstream target, period circadian regulator 1 (PER1), thereby promoting bladder cancer cell proliferation. METHODS: Expression of YTHDF2 in bladder cancer was predicted using The Cancer Genome Atlas (TCGA). Twenty paired bladder cancer and adjacent normal tissues were collected at the clinical level. Normal bladder epithelial cells (SV-HUC-1) and bladder cancer cell lines (T24, 5637, EJ-1, SW780, BIU-87) were examined by quantitative real-time PCR (RT-qPCR), Western blotting, and immunohistochemistry for expression of YTHDF2, PER1, and proliferation-related proteins [proliferating cell nuclear antigen (PCNA), minichromosome maintenance complex component 2 (MCM2), Cyclin D1]. YTHDF2 was silenced in 5637 and SW780 cells, and cell proliferation was assessed by Cell Counting Kit-8 (CCK-8), colony formation, and EdU assays. Bioinformatics was used to predict glycosylation sites of YTHDF2, and immunoprecipitation (IP) was performed to detect O-GlcNAc modification levels of YTHDF2 in tissues and cells. Bladder cancer cells were treated with DMSO, OSMI-1 (O-GlcNAc inhibitor), or Thiamet G (O-GlcNAc activator), followed by cycloheximide (CHX), to assess YTHDF2 ubiquitination by IP. YTHDF2 knockdown and Thiamet G treatment were further used to evaluate PER1 mRNA stability, PER1 m⁶A modification, and cell proliferation. TCGA was used to predict PER1 expression in tissues; SRAMP predicted potential PER1 m⁶A sites. Methylated RNA immunoprecipitation (MeRIP) assays measured PER1 m⁶A modification. Finally, the effects of knocking down YTHDF2 and PER1 on 5637 and SW780 cell proliferation were assessed. RESULTS: YTHDF2 expression was significantly upregulated in bladder cancer tissues compared with adjacent tissues (mRNA: 2.5-fold; protein: 2-fold), which O-GlcNAc modification levels increased 3.5-fold (P<0.001). YTHDF2 was upregulated in bladder cancer cell lines, and its knockdown suppressed cell viability (P<0.001), downregulated PCNA, MCM2, and CyclinD1 (all P<0.05), reduced colony numbers 3-fold (P<0.01), and inhibited proliferation. YTHDF2 exhibited elevated O-GlcNAc modification in cancer cells. OSMI-1 reduced YTHDF2 protein stability (P<0.01) and enhanced ubiquitination, while Thiamet G exerted opposite effects (P<0.001). Thiamet G reversed the proliferation-suppressive effects of YTHDF2 knockdown, promoting cell proliferation (P<0.01) and upregulating PCNA, MCM2, and CyclinD1 (all P<0.05). Mechanistically, YTHDF2 targeted PER1 via m⁶A recognition, promoting PER1 mRNA degradation. Rescue experiments showed that PER1 knockdown reversed the inhibitory effect of YTHDF2 knockdown on cell proliferation, upregulated PCNA, MCM2, and Cyclin D1 (all P<0.05), and promoted bladder cancer cell proliferation (P<0.001). CONCLUSIONS O-GlcNAc modification YTHDF2 promotes bladder cancer development by downregulating the tumor suppressor gene PER1 through m⁶A-mediated post-transcriptional regulation.
Humans ; Urinary Bladder Neoplasms/metabolism* ; RNA-Binding Proteins/genetics* ; Cell Proliferation ; Cell Line, Tumor ; Disease Progression ; Acetylglucosamine/metabolism* ; Adenosine/metabolism* ; Gene Expression Regulation, Neoplastic ; Genes, Tumor Suppressor