The circadian clock plays a critical role in regulating various physiological processes, including gene expression, metabolic regulation, immune response, and the sleep-wake cycle in living organisms. Post-translational modifications (PTMs) are crucial regulatory mechanisms to maintain the precise oscillation of the circadian clock. By modulating the stability, activity, cell localization and protein-protein interactions of core clock proteins, PTMs enable these proteins to respond dynamically to environmental and intracellular changes, thereby sustaining the periodic oscillations of the circadian clock. Different types of PTMs exert their effects through distincting molecular mechanisms, collectively ensuring the proper function of the circadian system. This review systematically summarized several major types of PTMs, including phosphorylation, acetylation, ubiquitination, SUMOylation and oxidative modification, and overviewed their roles in regulating the core clock proteins and the associated pathways, with the goals of providing a theoretical foundation for the deeper understanding of clock mechanisms and the treatment of diseases associated with circadian disruption.
Protein Processing, Post-Translational/physiology* ; Circadian Rhythm/physiology* ; Humans ; Animals ; CLOCK Proteins/physiology* ; Circadian Clocks/physiology* ; Phosphorylation ; Acetylation ; Ubiquitination ; Sumoylation

This study aims to explore the specific mechanism by which puerarin inhibits ferroptosis and improves the myocardial contractile function in myocardial hypertrophy through the nuclear factor erythroid 2-related factor 2(Nrf2)/antioxidant response element(ARE)/heme oxygenase-1(HO-1) signaling pathway. The hypertrophic cardiomyocyte model was established using phenylephrine, and H9c2 cells were divided into control group, model group, puerarin group, and puerarin+ML385 group. Cell viability and surface area were detected by cell counting kit-8(CCK-8) and immunofluorescence experiments. The mitochondrial membrane potential and Ca~(2+) concentration were measured. The ferroptosis-related indicators were detected by biochemical and fluorescence staining methods. The expression of proteins related to ferroptosis and the Nrf2/ARE/HO-1 signaling pathway was detected by Western blot. A myocardial hypertrophy model was established, and 40 rats were randomly divided into sham group, model group, puerarin group, and puerarin+Nrf2 inhibitor(ML385) group, with 10 rats in each group. Echocardiogram, hemodynamic parameters, and myocardial hypertrophy parameters were measured. Histopathological changes of myocardial tissues were observed by hematoxylin and eosin(HE) staining and Masson staining. Biochemical methods, enzyme-linked immunosorbent assay(ELISA), and fluorescence staining were used to detect inflammatory factors and ferroptosis-related indicators. Immunohistochemistry was used to detect the expression of proteins related to ferroptosis and the Nrf2/ARE/HO-1 signaling pathway. Cell experiments showed that puerarin intervention significantly enhanced the viability of hypertrophic cardiomyocytes, reduced their surface area, and restored mitochondrial membrane potential and Ca~(2+) homeostasis. Mechanism studies revealed that puerarin promoted Nrf2 nuclear translocation, upregulated the expression of HO-1, solute carrier family 7 member 11(SLC7A11), and glutathione peroxidase 4(GPX4), and decreased malondialdehyde(MDA), reactive oxygen species(ROS), and iron levels. These protective effects were reversed by ML385. In animal experiments, puerarin improved cardiac function in rats with myocardial hypertrophy, alleviated myocardial hypertrophy and fibrosis, inhibited inflammatory responses and ferroptosis, and promoted nuclear Nrf2 translocation and HO-1 expression. However, combined intervention with ML385 led to deterioration of hemodynamics and a rebound in ferroptosis marker levels. In conclusion, puerarin may inhibit cardiomyocyte ferroptosis through the Nrf2/ARE/HO-1 signaling pathway, thereby improving myocardial contractile function in myocardial hypertrophy.
Animals ; NF-E2-Related Factor 2/genetics* ; Rats ; Ferroptosis/drug effects* ; Signal Transduction/drug effects* ; Isoflavones/pharmacology* ; Male ; Rats, Sprague-Dawley ; Cardiomegaly/genetics* ; Myocytes, Cardiac/metabolism* ; Antioxidant Response Elements/drug effects* ; Myocardial Contraction/drug effects* ; Heme Oxygenase-1/genetics* ; Cell Line

The relationship between hyperuricemia (HUA) and erectile dysfunction (ED) remains inadequately understood. Given that HUA is often associated with various metabolic disorders, this study aims to explore the multivariate linear impacts of metabolic parameters on erectile function in ED patients with HUA. A cross-sectional analysis was conducted involving 514 ED patients with HUA in the Department of Andrology, Jiangsu Province Hospital of Chinese Medicine (Nanjing, China), aged 18 to 60 years. General demographic information, medical history, and laboratory results were collected to assess metabolic disturbances. Sexual function was evaluated using the 5-item version of the International Index of Erectile Function (IIEF-5) questionnaire. Based on univariate analysis, variables associated with IIEF-5 scores were identified, and the correlations between them were evaluated. The effects of these variables on IIEF-5 scores were further explored by multiple linear regression models. Fasting plasma glucose ( β = -0.628, P < 0.001), uric acid ( β = -0.552, P < 0.001), triglycerides ( β = -0.088, P = 0.047), low-density lipoprotein cholesterol ( β = -0.164, P = 0.027), glycated hemoglobin (HbA1c; β = -0.562, P = 0.012), and smoking history ( β = -0.074, P = 0.037) exhibited significant negative impacts on erectile function. The coefficient of determination ( R ²) for the model was 0.239, and the adjusted R ² was 0.230, indicating overall statistical significance ( F -statistic = 26.52, P < 0.001). Metabolic parameters play a crucial role in the development of ED. Maintaining normal metabolic indices may aid in the prevention and improvement of erectile function in ED patients with HUA.
Humans ; Male ; Erectile Dysfunction/metabolism* ; Hyperuricemia/metabolism* ; Adult ; Middle Aged ; Cross-Sectional Studies ; Glycated Hemoglobin/metabolism* ; Blood Glucose/metabolism* ; Uric Acid/blood* ; Young Adult ; Triglycerides/blood* ; Adolescent ; Cholesterol, LDL/blood* ; Penile Erection/physiology* ; Surveys and Questionnaires

OBJECTIVE: To investigate the protective effect of achyranthes bidentata (AB) on sperm quality in mice with spermatogenic disorder through the glycolytic metabolic pathway and its action mechanism. METHODS: We equally randomized 40 Kunming mice into a normal control, a model control, a low-dose AB (3.5 g/kg) and a high-dose AB group (7.0 g/kg), and established the model of spermatogenic disorder in the latter three groups of mice by intraperitoneal injection of doxorubicin (30 mg/kg). Two days after modeling, we collected the testis and kidney tissues and blood samples from the mice for observation of the pathological changes in the testis tissue by HE staining, detection of perm motility with the sperm quality analyzer, examination of the apoptosis of testis cells by flow cytometry, measurement of the levels of testosterone (T), malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) in the serum and testis tissue by ELISA, and determination of expressions of the key enzymes of glycolysis hexokinase Ⅱ (HK2), pyruvate kinase M2 (PKM2), platelet phosphofructokinase (PFKP), lactate dehydrogenase A (LDHA) and the meiosis proteins REC8 and SCP3 by Western blot, and the mRNA expressions of glycolytic phosphofructokinase 1 (PFK1), phosphoglycerate kinase 1 (PGK1), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) by fluorescence quantitative PCR (FQ-PCR). RESULTS: Compared with the model controls, the mice in the AB groups showed significant increases in the testis coefficient, kidney index, sperm concentration, sperm motility, spermatogonia, primary spermatocytes, spermatids, sperm count and the serum T level (P<0.05 or P<0.01), but dramatic decreases in the apoptosis of testis cells and percentage of morphologically abnormal sperm (P<0.01). Achyranthes bidentata also significantly elevated the levels of SOD and CAT, and down-regulated the mRNA expressions of MDA, TNF-α and IL-1β (P<0.05 or P<0.01), and up-regulated the protein expressions of HK2, PKM2, PFKP, LDHA, REC8 and SCP3, and expressions of the glycolysis key genes Pfk1 and Pgk1 (P<0.05 or P<0.01). CONCLUSION Achyranthes bidentata ameliorates doxorubicin-induced spermatogenic disorder in mice by regulating the glycolytic pathway and reducing oxidative stress and the expressions of inflammatory factors.
Glycolysis/drug effects* ; Doxorubicin/toxicity* ; Spermatogenesis/drug effects* ; Random Allocation ; Male ; Animals ; Mice ; Disease Models, Animal ; Achyranthes/chemistry* ; Spermatozoa/pathology* ; Oxidative Stress/drug effects* ; Primary Cell Culture ; Apoptosis/drug effects* ; Sperm Motility/drug effects* ; Testis/pathology* ; Infertility, Male/prevention & control* ; Medicine, Chinese Traditional/methods* ; Animals, Outbred Strains

OBJECTIVE: To evaluate the anti-hepatocellular carcinoma (HCC) activity of total alkaloids from Gelsemium elegans Benth. (TAG) in vivo and in vitro and to elucidate their potential mechanisms of action through transcriptomic analysis. METHODS: TAG extraction was conducted, and the primary components were quantified using high-performance liquid chromatography (HPLC). The effects of TAG (100, 150, and 200 µg/mL) on various tumor cells, including SMMC-7721, HepG2, H22, CAL27, MCF7, HT29, and HCT116, were assessed. Effects of TAG on HCC proliferation and apoptosis were detected by colony formation assays and cell stainings. Caspase-3, Bcl-2, and Bax protein levels were detected by Western blotting. In vivo, a tumor xenograft model was developed using H22 cells. Totally 40 Kunming mice were randomly assigned to model, cyclophosphamide (20 mg/kg), TAG low-dose (TAG-L, 0.5 mg/kg), and TAG high-dose (TAG-H, 1 mg/kg) groups, with 10 mice in each group. Tumor volume, body weight, and tumor weight were recorded and compared during 14-day treatment. Immune organ index were calculated. Tissue changes were oberseved by hematoxylin and eosin staining and immunohistochemistry. Additionally, transcriptomic and metabolomic analyses, as well as quatitative real-time polymerase chain reaction (RT-qPCR), were performed to detect mRNA and metabolite expressions. RESULTS: HPLC successfully identified the components of TAG extraction. Live cell imaging and analysis, along with cell viability assays, demonstrated that TAG inhibited the proliferation of SMMC-7721, HepG2, H22, CAL27, MCF7, HT29, and HCT116 cells. Colony formation assays, Hoechst 33258 staining, Rhodamine 123 staining, and Western blotting revealed that TAG not only inhibited HCC proliferation but also promoted apoptosis (P<0.05). In vivo experiments showed that TAG inhibited the growth of solid tumors in HCC in mice (P<0.05). Transcriptomic analysis and RT-qPCR indicated that the inhibition of HCC by TAG was associated with the regulation of the key gene CXCL13. CONCLUSION TAG inhibits HCC both in vivo and in vitro, with its inhibitory effect linked to the regulation of the key gene CXCL13.
Animals ; Apoptosis/drug effects* ; Liver Neoplasms/genetics* ; Carcinoma, Hepatocellular/genetics* ; Humans ; Alkaloids/therapeutic use* ; Gelsemium/chemistry* ; Cell Line, Tumor ; Cell Proliferation/drug effects* ; Mice ; Xenograft Model Antitumor Assays

OBJECTIVE: To investigate the common mechanisms among collagen-induced arthritis (CIA), bleomycin (BLM)-induced pulmonary fibrosis, and CIA+BLM to evaluate the therapeutic effect of triptolide (TP) on CIA+BLM. METHODS: Thirty-six male Sprague-Dawley rats were randomly assigned to 6 groups according to a random number table (n=6 per group): normal control (NC), CIA, BLM, combined CIA+BLM model, TP low-dose (TP-L, 0.0931 mg/kg), and TP high-dose (TP-H, 0.1862 mg/kg) groups. The CIA model was induced by intradermal injection at the base of the tail with emulsion of bovine type II collagen and incomplete Freund's adjuvant (1:1), with 200 µL administered on day 0 and a booster of 100 µL on day 7. Pulmonary fibrosis was induced via a single intratracheal injection of BLM (5 mg/kg). The CIA+BLM model combined both protocols, and TP was administered orally from day 14 to 35. After successful modeling, arthritis scores were recorded every 3 days, and pulmonary function was assessed once at the end of the treatment period. Lung tissues were collected for histological analysis (hematoxylin eosin and Masson staining), immunohistochemistry, measurement of hydroxyproline (HYP) content, and calculation of lung coefficient. In addition, HE staining was performed on the ankle joint. Total RNA was extracted from lung tissues for transcriptomic analysis. Differentially expressed genes (DEGs) were compared with those from the RA-associated interstitial lung diseases patient dataset GSE199152 to identify overlapping genes, which were then used to construct a protein-protein interaction network. Hub genes were identified using multiple topological algorithms. RESULTS: The successfully established CIA+BLM rat model exhibited significantly increased arthritis scores and severe pulmonary fibrosis (P<0.01). By intersecting the DEGs obtained from transcriptomic analysis of lung tissues in CIA, BLM, and CIA+BLM rats with DEGs from rheumatoid arthritis-interstitial lung disease patients (GSE199152 dataset), 50 upregulated and 44 downregulated genes were identified. Through integrated PPI network analysis using multiple topological algorithms, IGF1 was identified as a central hub gene. TP intervention significantly improved pulmonary function by increasing peak inspiratory flow (P<0.01), and reduced lung index and HYP content (P<0.01). Histopathological analysis showed that TP alleviated alveolar collapse, interstitial thickening, and collagen deposition in the lung tissues (P<0.01). Moreover, TP treatment reduced the expression of collagen type I and α-SMA and increased E-cadherin levels (P<0.01). TP also significantly reduced arthritis scores and ameliorated synovial inflammation (P<0.05). Both transcriptomic and immunohistochemical analyses confirmed that IGF1 expression was elevated in the CIA+BLM group and downregulated following TP treatment (P<0.05). CONCLUSION TP exerts protective effects in the CIA+BLM model by alleviating arthritis and pulmonary fibrosis through the inhibition of IGF1-mediated EMT.
Animals ; Pulmonary Fibrosis/complications* ; Bleomycin/adverse effects* ; Phenanthrenes/pharmacology* ; Male ; Rats, Sprague-Dawley ; Diterpenes/pharmacology* ; Epoxy Compounds/therapeutic use* ; Arthritis, Experimental/complications* ; Insulin-Like Growth Factor I/metabolism* ; Rats ; Lung/physiopathology*

Glutamine provides carbon and nitrogen to support the proliferation of cancer cells. However, the precise reason why cancer cells are particularly dependent on glutamine remains unclear. In this study, we report that glutamine modulates the tumor suppressor F-box and WD repeat domain-containing 7 (FBW7) to promote cancer cell proliferation and survival. Specifically, lysine 604 (K604) in the sixth of the 7 substrate-recruiting WD repeats of FBW7 undergoes glutaminylation (Gln-K604) by glutaminyl tRNA synthetase. Gln-K604 inhibits SCFFBW7-mediated degradation of c-Myc and Mcl-1, enhances glutamine utilization, and stimulates nucleotide and DNA biosynthesis through the activation of c-Myc. Additionally, Gln-K604 promotes resistance to apoptosis by activating Mcl-1. In contrast, SIRT1 deglutaminylates Gln-K604, thereby reversing its effects. Cancer cells lacking Gln-K604 exhibit overexpression of c-Myc and Mcl-1 and display resistance to chemotherapy-induced apoptosis. Silencing both c-MYC and MCL-1 in these cells sensitizes them to chemotherapy. These findings indicate that the glutamine-mediated signal via Gln-K604 is a key driver of cancer progression and suggest potential strategies for targeted cancer therapies based on varying Gln-K604 status.
Glutamine/metabolism* ; Myeloid Cell Leukemia Sequence 1 Protein/genetics* ; Humans ; Proto-Oncogene Proteins c-myc/genetics* ; Cell Proliferation ; Signal Transduction ; Neoplasms/pathology* ; F-Box-WD Repeat-Containing Protein 7/genetics* ; Cell Survival ; Cell Line, Tumor ; Apoptosis