The molecular mechanism of verbascoside(OC1) in promoting acetylcholine(ACh) release in the pathogenesis of Alzheimer's disease(AD) was studied. Adrenal pheochromocytoma cells(PC12) of rats induced by β-amyloid protein(1-42)(Aβ_(1-42)) were used as AD models in vitro and were divided into control group, model group(Aβ_(1-42) 10 μmol·L~(-1)), OC1 treatment group(2 and 10 μg·mL~(-1)). The effect of OC1 on phosphorylated proteins in AD models was analyzed by whole protein phosphorylation quantitative omics, and the selectivity of OC1 for calcium channel subtypes was virtually screened in combination with computer-aided drug design. The fluorescence probe Fluo-3/AM was used to detect Ca~(2+) concentration in cells. Western blot analysis was performed to detect the effects of OC1 on the expression of phosphorylated calmodulin-dependent protein kinase Ⅱ(p-CaMKⅡ, Thr286) and synaptic vesicle-related proteins, and UPLC/Q Exactive MS was used to detect the effects of OC1 on ACh release in AD models. The effects of OC1 on acetylcholine esterase(AChE) activity in AD models were detected. The results showed that the differentially modified proteins in the model group and the OC1 treatment group were related to calcium channel activation at three levels: GO classification, KEGG pathway, and protein domain. The results of molecular docking revealed the dominant role of L-type calcium channels. Fluo-3/AM fluorescence intensity decreased under the presence of Ca~(2+) chelating agent ethylene glycol tetraacetic acid(EGTA), L-type calcium channel blocker verapamil, and N-type calcium channel blocker conotoxin, and the effect of verapamil was stronger than that of conotoxin. This confirmed that OC1 promoted extracellular Ca~(2+) influx mainly through its interaction with L-type calcium channel protein. In addition, proteomic analysis and Western blot results showed that the expression of p-CaMKⅡ and downstream vesicle-related proteins was up-regulated after OC1 treatment, indicating that OC1 acted on vesicle-related proteins by activating CaMKⅡ and participated in synaptic remodeling and transmitter release, thus affecting learning and memory. OC1 also decreased the activity of AChE and prolonged the action time of ACh in synaptic gaps.
Animals ; Rats ; Glucosides/administration & dosage* ; Acetylcholine/metabolism* ; Alzheimer Disease/genetics* ; PC12 Cells ; Phenols/chemistry* ; Neurotransmitter Agents/metabolism* ; Drugs, Chinese Herbal ; Calcium-Calmodulin-Dependent Protein Kinase Type 2/genetics* ; Humans ; Phosphorylation/drug effects* ; Calcium/metabolism* ; Polyphenols

Objective The aim of this study was to investigate the effect of p38 on stem cell maintenance of pancreatic cancer. Methods Human pancreatic cancer cells PANC-1 were treated with different concentrations of 5-fluorouracil(5-FU)(0.5×IC₅₀, IC₅₀, and 2×IC₅₀) for 24 hours, and VX-702 (p38 phosphorylation inhibitor) was added, and the cells were inoculated in 6-well culture dishes with ultra-low adhesion to observe the changes of sphere tumors. The expression levels of cyclin-dependent kinase 2(CDK2), cyclin B1 and D1, Octamer-binding transcription factor 4(OCT4), SRY-box transcription factor 2(SOX2), Nanog and p38 were measured by Western blot. The mRNA expression levels of p38, OCT4, Nanog and SOX2 were tested by RT-PCR. Cell cycle, apoptosis, and the proportion of CD44⁺CD133⁺PANC-1 cells were evaluated by flow cytometry. Results The results showed that 5-FU inhibited the formation of tumor spheres in PANC-1 cells, increased CD44⁺CD133⁺cell fragments, down-regulated the expression of OCT4, Nanog and SOX2, and inhibited the stemness maintenance of PANC-1 tumor stem cells. Phosphorylation of PANC-1 cells was inhibited by a highly selective p38 MAPK inhibitor, VX-702(p38 mitogen-activated protein kinase inhibitor), which had the same effect as 5-FU treatment. When VX-702 combined with 5-FU was used to treat PANC-1 cells, the therapeutic effect was enhanced. Conclusion p38 inhibitors decreased PANC-1 cell activity and increased cell apoptosis. p38 inhibitors inhibit the stemness maintenance of pancreatic cancer stem cells.
Humans ; Phosphorylation/drug effects* ; Cell Line, Tumor ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors* ; Neoplastic Stem Cells/metabolism* ; Drug Resistance, Neoplasm/drug effects* ; Fluorouracil/pharmacology* ; Pancreatic Neoplasms/pathology* ; Apoptosis/drug effects* ; SOXB1 Transcription Factors/genetics* ; Octamer Transcription Factor-3/genetics*

Objective To investigate the effect of FUNDC1 tyrosine phosphorylation site mutations on mitophagy in H9c2 myocardial cells by constructing tyrosine site mutant plasmids (Y11 and Y18) of the FUN14 domain-containing protein 1 (FUNDC1). Methods The mutant plasmids constructed by whole-gene synthesis were transfected into rat myocardial H9c2 cells and divided into five groups: empty plasmid group, FUNDC1 overexpression group, Y11 mutant group, Y18 mutant group, and Y11 combined with Y18 mutant group. The viability of H9c2 cells was assessed using the CCK-8 assay. Additionally, tetramethylrhodamine ethyl ester (TMRE) staining was utilized to detect mitochondrial membrane potential. The protein expression levels of FUNDC1, translocase of the outer mitochondrial membrane 20 (TOM20), and cytochrome c oxidase IV (COX IV) were detected by Western blot analysis. Confocal microscopy was used to evaluate transfection efficiency as well as the co-localization of mitochondria and lysosomes. Results The FUNDC1 overexpression, Y11, Y18, and Y11 combined with Y18 mutant plasmids were successfully constructed. After plasmid transfection, widespread GFP fluorescence expression was observed under confocal microscopy. Compared with the empty plasmid group, FUNDC1 protein expression levels were significantly increased in the FUNDC1 overexpression group, Y11 mutation group, Y18 mutation group, and Y11 combined with Y18 mutation group, while cell viability and mitochondrial membrane potential showed no significant changes. Compared to the empty plasmid group, cells transfected with Y18 and Y11 combined with Y18 mutant plasmids showed increased TOM20 and COX IV expression levels and decreased mitochondrial-lysosomal co-localization. Conclusion Transfection with FUNDC1 Y18 or Y11 combined with Y18 mutant plasmids inhibited mitophagy in H9c2 myocardial cells.
Animals ; Rats ; Mitophagy/genetics* ; Myocytes, Cardiac/cytology* ; Mitochondrial Proteins/metabolism* ; Mutation ; Phosphorylation ; Tyrosine/genetics* ; Cell Line ; Membrane Proteins/metabolism* ; Membrane Potential, Mitochondrial

OBJECTIVES: To investigate the clinical features and gene mutation characteristics of combined oxidative phosphorylation deficiency type 7 (COXPD7) caused by mutations in the C12orf65 gene, and to enhance the awareness of this disease. METHODS: A child diagnosed with COXPD7 in the Department of Neurology, Children's Hospital Affiliated to Zhengzhou University in 2021 was included, along with 10 patients reported in the literature. All subjects were analyzed for their genotypes and clinical phenotypes. RESULTS: A total of 11 patients with COXPD7 were included, comprising 1 reported in this study and 10 from the literature. Among the 11 patients, 9 had homozygous mutations in the C12orf65 gene, while 2 had compound heterozygous mutations, which were identified as frameshift or nonsense mutations. The age of onset ranged from 1 day to 2 years, and clinical manifestations included optic nerve atrophy and delays in intellectual and motor development. Eight patients exhibited external ophthalmoplegia, and five patients displayed spastic paralysis. Cranial magnetic resonance imaging revealed optic nerve atrophy in all 11 patients, abnormal brainstem signals in 10 patients, and a lactate peak on brainstem magnetic resonance spectroscopy scans in 3 patients. CONCLUSIONS COXPD7 associated with the C12orf65 gene results from homozygous or compound heterozygous mutations, with primary clinical manifestations of optic nerve atrophy and delays in intellectual and motor development. Some patients may also present with spastic paralysis or external ophthalmoplegia. Cranial imaging reveals symmetrical abnormal signals in bilateral basal ganglia and brainstem, and a lactate peak is observed on brainstem magnetic resonance spectroscopy scans.
Child, Preschool ; Female ; Humans ; Infant ; Male ; Mitochondrial Diseases/genetics* ; Mitochondrial Proteins/genetics* ; Mutation ; Oxidative Phosphorylation ; Infant, Newborn

Oral squamous cell carcinoma (OSCC) progresses from preneoplastic precursors via genetic and epigenetic alterations. Previous studies have focused on the treatment of terminally developed OSCC. However, the role of epigenetic regulators as therapeutic targets during the transition from preneoplastic precursors to OSCC has not been well studied. Our study identified lysine-specific demethylase 1 (LSD1) as a crucial promoter of OSCC, demonstrating that its knockout or pharmacological inhibition in mice reversed OSCC preneoplasia. LSD1 inhibition by SP2509 disrupted cell cycle, reduced immunosuppression, and enhanced CD4+ and CD8+ T-cell infiltration. In a feline model of spontaneous OSCC, a clinical LSD1 inhibitor (Seclidemstat or SP2577) was found to be safe and effectively inhibit the STAT3 network. Mechanistic studies revealed that LSD1 drives OSCC progression through STAT3 signaling, which is regulated by phosphorylation of the cell cycle mediator CDK7 and immunosuppressive CTLA4. Notably, LSD1 inhibition reduced the phosphorylation of CDK7 at Tyr170 and eIF4B at Ser422, offering insights into a novel mechanism by which LSD1 regulates the preneoplastic-to-OSCC transition. This study provides a deeper understanding of OSCC progression and highlights LSD1 as a potential therapeutic target for controlling OSCC progression from preneoplastic lesions.
STAT3 Transcription Factor/metabolism* ; Animals ; Histone Demethylases/genetics* ; Phosphorylation ; Mouth Neoplasms/immunology* ; Mice ; Carcinoma, Squamous Cell/immunology* ; Disease Progression ; Cyclin-Dependent Kinase-Activating Kinase ; Precancerous Conditions/metabolism* ; Humans ; Cyclin-Dependent Kinases/metabolism* ; Disease Models, Animal

Hypoxia and aberrant activation of epidermal growth factor receptor (EGFR) are considered important features of various malignancies. However, whether hypoxia can directly trigger EGFR activation and its clinical implications remain unclear. In this study, we demonstrated that in oral cancer, a typical hypoxic tumor, hypoxia can induce chronic but constitutive phosphorylation of wild-type EGFR in the absence of ligands. Oral cancer cell lines exhibit different EGFR phosphorylation responses to hypoxia. In hypoxic HN4 and HN6 cells, ubiquitination-mediated endocytosis, lysosomal sorting, and degradation lead to low levels of EGFR phosphorylation. However, in CAL-27 and HN30 cells, a novel HIF-1α-induced long noncoding RNA (lncRNA), EUDAL, can compete with the E3 ligase/adaptor complex c-Cbl/Grb2 for binding to EGFR, stabilizing phosphorylated EGFR (pEGFR) and resulting in sustained activation of EGFR and its downstream STAT3/BNIP3 signaling. STAT3/BNIP3-mediated autophagy leads to antitumor drug resistance. A high EUDAL/EGFR/STAT3/autophagy pathway activation predicts poor response to chemotherapy in oral cancer patients. Collectively, hypoxia can induce noncanonical ligand-independent EGFR phosphorylation. High EUDAL expression facilitates sustained EGFR phosphorylation in hypoxic tumor cells and leads to autophagy-related drug resistance.
Humans ; ErbB Receptors/metabolism* ; Mouth Neoplasms/pathology* ; RNA, Long Noncoding/genetics* ; Drug Resistance, Neoplasm/genetics* ; Cell Line, Tumor ; Phosphorylation ; Signal Transduction ; STAT3 Transcription Factor/metabolism* ; Cell Hypoxia ; Autophagy ; Proto-Oncogene Proteins c-cbl/metabolism*

Tissue formation and organ homeostasis are achieved by precise coordination of proliferation and differentiation of stem cells and progenitors. While deregulation of these processes can result in degenerative disease or cancer, their molecular interplays remain unclear. Here we show that the switch of human pluripotent stem cell (hPSC) self-renewal to differentiation is associated with the induction of distinct cyclin-dependent kinase inhibitors (CDKIs). In hPSCs, Activin/Nodal/TGFβ signaling maintains CDKIs in a poised state via SMAD2/3-NANOG-OCT4-EZH2-SNON transcriptional complex. Upon gradual differentiation, CDKIs are induced by successive transcriptional complexes between SMAD2/3-SMYD2 and developmental regulators such as EOMES, thereby lengthening the G1 phase. This, in turn, induces SMAD2/3 transcriptional activity by blocking its linker phosphorylation. Such SMAD2/3-CDKI positive feedback loops drive the exit from pluripotency and stepwise cell-fate specification that could be harnessed for producing cells for therapeutic applications. Our study uncovers fundamental mechanisms of how cell-fate specification is interconnected to cell-cycle dynamics and provides insight into autonomous circuitries governing tissue self-formation.
Humans ; Smad2 Protein/genetics* ; Smad3 Protein/genetics* ; Cell Differentiation ; Pluripotent Stem Cells/metabolism* ; Signal Transduction ; Octamer Transcription Factor-3/genetics* ; Enhancer of Zeste Homolog 2 Protein/genetics* ; Nanog Homeobox Protein/genetics* ; Phosphorylation

Abiotic stresses substantially affect the growth and development of plants. Plants have evolved multiple strategies to cope with the environmental stresses, among which transcription factors play an important role in regulating the tolerance to abiotic stresses. Basic leucine zipper transcription factors (bZIP) are one of the largest gene families. The stability and activity of bZIP transcription factors could be regulated by different post-translational modifications (PTMs) in response to various intracellular or extracellular stresses. This paper introduces the structural feature and classification of bZIP transcription factors, followed by summarizing the PTMs of bZIP transcription factors, such as phosphorylation, ubiquitination and small ubiquitin-like modifier (SUMO) modification, in response to abiotic stresses. In addition, future perspectives were prospected, which may facilitate cultivating excellent stress-resistant crop varieties by regulating the PTMs of bZIP transcription factors.
Basic-Leucine Zipper Transcription Factors/genetics* ; Protein Processing, Post-Translational ; Phosphorylation ; Transcription Factors/genetics* ; Stress, Physiological/genetics*

OBJECTIVES: To investigate the regulatory mechanism of aurora kinase B (AURKB) for promoting malignant phenotype of osteosarcoma cells. METHODS: HA-Vector or HA-AURKB was transfected in 293T cells to identify the molecules interacting with AURKB using immunoprecipitation combined with liquid chromatography-tandem mass spectrometry followed by verification with co-immunoprecipitation and Western blotting. In cultured osteosarcoma cells with lentivirus-mediated RNA interference of AURKB or DHX9 or their overexpression, the changes in cell proliferation, migration, and invasion activities were observed with EDU and Transwell assays. Mechanistic analysis was performed using Co-IP and in vivo ubiquitination experiments to detect the interaction between AURKB and DHX9 and the phosphorylation and ubiquitination levels of DHX9. Western blotting was used to detect the effect of AURKB and DHX9 on activation of nuclear factor-κB (NF-κB) signaling. RESULTS: AURKB was highly expressed in osteosarcoma cell lines, and in osteosarcoma 143B cells, AURKB silencing significantly reduced cell proliferation, migration and invasion abilities. Interactions between AURKB and DHX9 were detected, and they were both highly expressed in osteosarcoma tissues; silencing AURKB reduced the protein expression of DHX9, and AURKB overexpression increased DHX9 phosphorylation. Silencing AURKB did not significantly affect the transcription and translation of DHX9 but accelerated its degradation and ubiquitination. Overexpression of DHX9 effectively reversed the effects of AURKB silencing on IKBα protein and phosphorylated p65, promoted nuclear translocation of p65 to activate the NF-κB signaling pathway, and enhanced the proliferation, migration, and invasion abilities of cultured osteosarcoma cells. CONCLUSIONS AURKB overexpression promotes the malignant phenotype of osteosarcoma cells by activating the NF-κB signaling pathway via regulating DHX9.
Humans ; Osteosarcoma/genetics* ; Cell Proliferation ; NF-kappa B/metabolism* ; Signal Transduction ; Cell Line, Tumor ; Cell Movement ; DEAD-box RNA Helicases/genetics* ; Aurora Kinase B/genetics* ; Phenotype ; Bone Neoplasms/genetics* ; Neoplasm Invasiveness ; Phosphorylation ; Neoplasm Proteins

P21-activated kinase 5 (PAK5) belongs to the PAK-II subfamily, which is an important regulator of cell survival, adhesion, and motility. However, the functions of PAK5 in endometriosis remain unclear. Here, PAK5 is strikingly upregulated in endometriosis. Furthermore, the knockdown of PAK5 or its inhibitor GNE 2861 blocks the development of endometriosis, which is equally demonstrated in PAK5-knockout mice. In addition, PAK5 promotes glycolysis by enhancing the protein stability of pyruvate kinase 2 (PKM2) in endometriotic cells, which is a key enzyme for glucose metabolism. Moreover, the phosphorylation of PKM2 at Ser519 by PAK5 mediates endometriosis cell proliferation and metastasis. Collectively, PAK5 plays an indispensable role in endometriosis. Our findings demonstrate that PAK5 is an important target for the treatment of endometriosis.
Endometriosis/genetics* ; Female ; Animals ; p21-Activated Kinases/genetics* ; Mice ; Phosphorylation ; Glycolysis ; Humans ; Thyroid Hormone-Binding Proteins ; Membrane Proteins/genetics* ; Carrier Proteins/genetics* ; Cell Proliferation ; Mice, Knockout ; Thyroid Hormones/metabolism* ; Pyruvate Kinase/genetics*