Necroptosis is one of the regulated cell death, which involves receptor interacting protein kinase (RIPK) 1/RIPK3/mixed lineage kinase domain like protein (MLKL) signaling pathway. Among them, MLKL is the final execution of necroptosis. The formation of RIPK1/RIPK3/MLKL necrosome induces the phosphorylated MLKL, and the activated MLKL penetrates into the membrane bilayer to form membrane pores, which damages the integrity of the membrane and leads to cell death. In addition to participating in necroptosis, MLKL is also closely related to other cell death, such as NETosis, pyroptosis, and autophagy. Therefore, MLKL is involved in the pathological processes of various diseases related to abnormal cell death pathways (such as cardiovascular diseases, neurodegenerative diseases and cancer), and may be a therapeutic target of multiple diseases. Understanding the role of MLKL in different cell death can lay a foundation for seeking various MLKL-related disease targets, and also guide the development and application of MLKL inhibitors.
Protein Kinases/metabolism* ; Necroptosis/physiology* ; Receptor-Interacting Protein Serine-Threonine Kinases ; Signal Transduction ; Pyroptosis ; Apoptosis

This paper aimed to investigate the role and potential mechanism of p53 on primordial follicle activation. Firstly, the p53 mRNA expression in the ovary of neonatal mice at 3, 5, 7 and 9 days post-partum (dpp) and the subcellular localization of p53 were detected to confirm the expression pattern of p53. Secondly, 2 dpp and 3 dpp ovaries were cultured with p53 inhibitor Pifithrin-μ (PFT-μ, 5 μmol/L) or equal volume of dimethyl sulfoxide for 3 days. The function of p53 in primordial follicle activation was determined by hematoxylin staining and whole ovary follicle counting. The proliferation of cell was detected by immunohistochemistry. The relative mRNA levels and protein levels of the key molecules involved in the classical pathways associated with the growing follicles were examined by immunofluorescence staining, Western blot and real-time PCR, respectively. Finally, rapamycin (RAP) was used to intervene the mTOR signaling pathway, and ovaries were divided into four groups: Control, RAP (1 μmol/L), PFT-μ (5 μmol/L), PFT-μ (5 μmol/L) + RAP (1 μmol/L) groups. The number of follicles in each group was determined by hematoxylin staining and whole ovary follicle counting. The results showed that the expression of p53 mRNA was decreased with the activation of primordial follicles in physiological condition. p53 was expressed in granulosa cells and oocyte cytoplasm of the primordial follicles and growing follicles, and the expression of p53 in the primordial follicles was higher than that in the growing follicles. Inhibition of p53 promoted follicle activation and reduced the primordial follicle reserve. Inhibition of p53 promoted the proliferation of the granulosa cells and oocytes. The mRNA and protein expression levels of key molecules in the PI3K/AKT signaling pathway including AKT, PTEN, and FOXO3a were not significantly changed after PFT-μ treatment, while the expression of RPS6/p-RPS6, the downstream effectors of the mTOR signaling pathway, was upregulated. Inhibition of both p53 and mTOR blocked p53 inhibition-induced primordial follicle activation. Collectively, these findings suggest that p53 may inhibit primordial follicle activation through the mTOR signaling pathway to maintain the primordial follicle reserve.
Female ; Animals ; Mice ; Tumor Suppressor Protein p53/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Hematoxylin ; Signal Transduction/physiology* ; TOR Serine-Threonine Kinases ; Sirolimus ; RNA, Messenger

Cell cycle plays a crucial role in cell development. Cell cycle progression is mainly regulated by cyclin dependent kinase (CDK), cyclin and endogenous CDK inhibitor (CKI). Among these, CDK is the main cell cycle regulator, binding to cyclin to form the cyclin-CDK complex, which phosphorylates hundreds of substrates and regulates interphase and mitotic progression. Abnormal activity of various cell cycle proteins can cause uncontrolled proliferation of cancer cells, which leads to cancer development. Therefore, understanding the changes in CDK activity, cyclin-CDK assembly and the role of CDK inhibitors will help to understand the underlying regulatory processes in cell cycle progression, as well as provide a basis for the treatment of cancer and disease and the development of CDK inhibitor-based therapeutic agents. This review focuses on the key events of CDK activation or inactivation, and summarizes the regulatory processes of cyclin-CDK at specific times and locations, as well as the progress of research on relevant CDK inhibitor therapeutics in cancer and disease. The review concludes with a brief description of the current challenges of the cell cycle process, with the aim to provide scientific references and new ideas for further research on cell cycle process.
Cyclin-Dependent Kinases/metabolism* ; Cyclins/metabolism* ; Protein Serine-Threonine Kinases ; Cell Cycle Proteins/metabolism* ; Cell Cycle/physiology* ; Cyclin-Dependent Kinase 2

To explore the effect and mechanism of Zuogui Pills in promoting neural tissue recovery and functional recovery in mice with ischemic stroke. Male C57BL/6J mice were randomly divided into a sham group, a model group, and low-, medium, and high-dose Zuogui Pills groups(3.5, 7, and 14 g·kg~(-1)), with 15 mice in each group. The ischemic stroke model was established using photochemical embolization. Stiker remove and irregular ladder walking behavioral tests were conducted before modeling and on days 7, 14, 21, and 28 after medication. Triphenyl tetrazolium chloride(TTC) staining was performed on day 3 after modeling, and T2-weighted imaging(T2WI) and diffusion-weighted imaging(DWI) were performed on day 28 after medication to evaluate the extent of brain injury. Hematoxylin-eosin(HE) staining was performed to observe the histology of the cerebral cortex. Axonal marker proteins myelin basic protein(MBP), growth-associated protein 43(GAP43), mammalian target of rapamycin(mTOR), and its downstream phosphorylated s6 ribosomal protein(p-S6), as well as mechanism-related proteins osteopontin(OPN) and insulin-like growth factor 1(IGF-1), were detected using immunofluorescence and Western blot. Zuogui Pills had a certain restorative effect on the neural function impairment caused by ischemic stroke in mice. TTC staining showed white infarct foci in the sensory-motor cortex area, and T2WI imaging revealed cystic necrosis in the sensory-motor cortex area. The Zuogui Pills groups showed less brain tissue damage, fewer scars, and more capillaries. The number of neuronal axons in those groups was higher than that in the model group, and neuronal activity was stronger. The expression of GAP43, OPN, IGF-1, and mTOR proteins in the Zuogui Pills groups was higher than that in the model group. In summary, Zuogui Pills can promote the recovery of neural function and axonal growth in mice with ischemic stroke, and its mechanism may be related to the activation of the OPN/IGF-1/mTOR signaling pathway.
Mice ; Animals ; Male ; Ischemic Stroke ; Recovery of Function/physiology* ; Insulin-Like Growth Factor I/pharmacology* ; Mice, Inbred C57BL ; TOR Serine-Threonine Kinases/metabolism* ; Stroke/drug therapy* ; Brain Ischemia/drug therapy* ; Mammals/metabolism*

BACKGROUND: Abnormally activated mechanistic target of rapamycin (mTOR) pathway has been reported in several model animals with inherited metabolic myopathies (IMMs). However, the profiles of mTOR pathway in skeletal muscles from patients are still unknown. This study aimed to analyze the activity of mTOR pathway in IMMs muscles. METHODS: We collected muscle samples from 25 patients with mitochondrial myopathy (MM), lipid storage disease (LSD) or Pompe disease (PD). To evaluate the activity of mTOR pathway in muscle specimens, phosphorylation of S6 ribosomal protein (p-S6) and p70S6 kinase (p-p70S6K) were analyzed by Western blotting and immunohistochemistry. RESULTS: Western blotting results showed that p-p70S6K/p70S6K in muscles from LSD and MM was up-regulated when compared with normal controls (NC) (NC vs. LSD, U = 2.000, P = 0.024; NC vs. MM: U = 6.000, P = 0.043). Likewise, p-S6/S6 was also up-regulated in muscles from all three subgroups of IMMs (NC vs. LSD, U = 0.000, P = 0.006; NC vs. PD, U = 0.000, P = 0.006; NC vs. MM, U = 1.000, P = 0.007). Immunohistochemical study revealed that p-S6 was mainly expressed in fibers with metabolic defect. In MM muscles, most p-S6 positive fibers showed cytochrome C oxidase (COX) deficiency (U = 5.000, P = 0.001). In LSD and PD muscles, p-S6 was mainly overexpressed in fibers with intramuscular vacuoles containing lipid droplets (U = 0.000, P = 0.002) or basophilic materials (U = 0.000, P = 0.002). CONCLUSION The mTOR pathway might be activated in myofibers with various metabolic defects, which might provide evidence for mTOR inhibition therapy in human IMMs.
Adolescent ; Adult ; Aged ; Blotting, Western ; Child ; Child, Preschool ; Female ; Glycogen Storage Disease Type II ; genetics ; metabolism ; Humans ; Immunohistochemistry ; In Vitro Techniques ; Lipid Metabolism, Inborn Errors ; genetics ; metabolism ; Male ; Middle Aged ; Mitochondrial Myopathies ; genetics ; metabolism ; Muscular Diseases ; genetics ; metabolism ; Signal Transduction ; genetics ; physiology ; TOR Serine-Threonine Kinases ; metabolism ; Young Adult

OBJECTIVE: To establish an arterial remodeling model of rats and to investigate the expression and role of Hippo signaling pathway in this model. METHODS: In the model group (n=40), the left common carotid artery was removed through the median incision of the neck. The 6-0 non-absorbable line was used to ligate the carotid artery near the proximal end as far as possible, completely blocking the blood flow. The common carotid artery of rats in control group (n=20) was not ligated using the operative line. After 14 days, the animals were sacrificed and the common carotid arteries were separated through the original surgical pathway and the arteries from the ligature to the distal end were collected. Arterial morphology and fibrosis were observed by HE and MASSON staining. Immunohistochemical staining was used to detect the expressions of anti-α smooth muscle actin (α-MSA) and proliferating cell nuclear antigen (PCNA) in the carotid artery. Western blot was used to detect the expressions of yes associated protein (YAP), transcriptional coactivator with PDZ-binding motif (TAZ), TEAD1, Bcl-2-like protein 4 (Bax), and B-cell lymphoma-2 (Bcl-2). RESULTS: Compared with the control group, the HE staining showed that the vascular remodeling was obvious, the ratio of the neointima/middle membrane was increased significantly, and the MASSON staining indicated that the fibrosis was significantly increased in model group. The immunohistochemical staining suggested that the expressions of α-SMA and PCNA were increased significantly; Western blot suggested that the expressions of YAP, TAZ, TEAD1, and Bcl-2 were increased in carotid artery of the model group. While the expression of Bax and the ratio of Bax/Bcl-2 were decreased. CONCLUSION A rat model of arterial remodeling mediated by carotid artery ligation was established successfully in this study. Hippo signaling pathway was proved to be activated in the arterial remodeling model induced by carotid artery ligation in rats, and might regulate the change of Bax/Bcl-2 ratio related to proliferation and apoptosis, and subsequently involved in the proliferation of smooth muscle cells to promote vascular remodeling.
Animals ; Carotid Arteries ; metabolism ; Carotid Artery, Common ; Cell Proliferation ; Myocytes, Smooth Muscle ; Protein-Serine-Threonine Kinases ; metabolism ; Rats ; Signal Transduction ; Vascular Remodeling ; physiology

The aim of this study was to investigate the role of S100 calcium binding protein A16 (S100A16) in lipid metabolism in hepatocytes and its possible biological mechanism. HepG2 cells (human hepatoma cell line) were cultured with fatty acid to establish fatty acid culture model. The control model was cultured without fatty acid. Each model was divided into three groups and transfected with S100a16 over-expression, shRNA and vector plasmids, respectively. The concentration of triglyceride (TG) in the cells was measured by kit, and the lipid droplets was observed by oil red O staining. Immunoprecipitation and mass spectrometry were used to find the interesting proteins interacting with S100A16, and the interaction was verified by immunoprecipitation. The further mechanism was studied by Western blot and qRT-PCR. The results showed that the intracellular lipid droplet and TG concentrations in the fatty acid culture model were significantly higher than those in the control model. The accumulation of intracellular fat in the S100a16 over-expression group was significantly higher than that in the vector plasmid transfection group. There was an interaction between heat shock protein A5 (HSPA5) and S100A16. Over-expression of S100A16 up-regulated protein expression levels of HSPA5, inositol-requiring enzyme 1α (IRE1α) and pIREα1, which belong to endoplasmic reticulum stress HSPA5/IRE1α-XBP1 pathway. Meanwhile, over-expression of S100A16 up-regulated the mRNA expression levels of adipose synthesis-related gene Srebp1c, Acc and Fas. In the S100a16 shRNA plasmid transfection group, the above-mentioned protein and mRNA levels were lower than those of vector plasmid transfection group. These results suggest that S100A16 may promote lipid synthesis in HepG2 cells through endoplasmic reticulum stress HSPA5/IRE1α-XBP1 pathway.
Endoplasmic Reticulum Stress ; Endoribonucleases ; physiology ; Heat-Shock Proteins ; physiology ; Hep G2 Cells ; Humans ; Lipid Metabolism ; Protein-Serine-Threonine Kinases ; physiology ; S100 Proteins ; physiology ; Triglycerides ; biosynthesis ; X-Box Binding Protein 1 ; physiology

BackgroundRecent studies have indicated that autophagy is involved in sepsis-induced myocardial dysfunction. This study aimed to investigate the change of autophagy in cecal ligation and puncture (CLP)-induced myocardium dysfunction and its relationship with mammalian target of rapamycin (mTOR) pathway.

MethodsTotally, 12 rats were randomly divided into CLP group or sham-operated (SHAM) group. Cardiac tissues were harvested 18 h after CLP or sham operation. Pathology was detected by hematoxylin and eosin staining, cardiac functions by echocardiography, distribution of microtubule-associated protein light chain 3 type II (LC3II) by immunohistochemical staining, and autophagic vacuoles by transmission electron microscopy. Moreover, phosphorylation of mTOR (p-mTOR), phosphorylation of S6 kinase-1 (PS6K1), and LC3II and p62 expression were measured by western blotting. Pearson's correlation coefficient was used to analyze the correlation of two parameters.

ResultsThe results by pathology and echocardiography revealed that there was obvious myocardial injury in CLP rats (left ventricle ejection fraction: SHAM 0.76 ± 0.06 vs. CLP 0.59 ± 0.11, P < 0.01; fractional shortening: SHAM 0.51 ± 0.09 vs. CLP 0.37 ± 0.06, P < 0.05). We also found that the autophagy process was elevated by CLP, the ratio of LC3II/LC3I was increased (P < 0.05) while the expression of p62 was decreased (P < 0.05) in the CLP rats, and there were also more autophagosomes and autolysosomes in the CLP rats. Furthermore, the mTOR pathway in CLP myocardium was inhibited when compared with the sham-operated rats; p-mTOR (P < 0.01) and PS6K1 (P < 0.05) were both significantly suppressed following CLP challenge. Interestingly, we found that the mTOR pathway was closely correlated with the autophagy processes. In our study, while p-mTOR in the myocardium was significantly correlated with p62 (r = 0.66, P = 0.02), PS6K1 was significantly positively correlated with p62 (r = 0.70, P = 0.01) and negatively correlated with LC3II (r = -0.71, P = 0.01).

ConclusionsThe autophagy process in the myocardium was accelerated in CLP rats, which was closely correlated with the inhibition of the mTOR pathway.

Animals ; Autophagy ; physiology ; Cecum ; injuries ; Echocardiography ; Immunohistochemistry ; Ligation ; Male ; Microscopy, Electron, Transmission ; Myocardium ; metabolism ; Rats ; Rats, Wistar ; Sepsis ; metabolism ; TOR Serine-Threonine Kinases ; metabolism

OBJECTIVE: To investigate the effect of large tumor suppressor homolog 2 (LATS2) gene overexpression on the proliferation and apoptosis of oral squamous cell carcinoma (OSCC). METHODS: Lentivirous particles were transferred into SCC-25 cell to upregulate LATS2 gene expression. Cell proliferation was detected by CCK-8 assay. Apoptosis was detected through flow cytometry. The expression changes of Bax, Bcl-2, and LATS2 were analyzed by Western blot. RESULTS: Gene transfection increased LATS2 expression. Compared with the control group and pEGFP-control group, SCC-25 cell proliferation in the pGFP-LATS2 group was inhibited, whereas the apoptosis ratio increased (P<0.05). Bcl-2 expression decreased, and Bax expression increased. CONCLUSIONS Overexpression of LATS2 could inhibit SCC-25 cell proliferation and induce apoptosis.
Apoptosis ; Carcinoma, Squamous Cell ; genetics ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Humans ; Mouth Neoplasms ; genetics ; metabolism ; Protein-Serine-Threonine Kinases ; physiology ; Tumor Suppressor Proteins ; physiology

OBJECTIVETo study the expression and significance of the mammalian target of rapamycin (mTOR)/eukaryote initiating factor 4E binding protein 1(4EBP1)/hypoxia inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway in asthmatic mice.

METHODSForty SPF level 6-8 week-old female Balb/C mice were randomly divided into control, asthma, budesonide and mTOR inhibitor (rapamycin) intervention groups (n=10 each). The asthmatic mouse model was prepared via OVA induction and challenge test. The intervention groups were administered with rapamycin at the dosage of 3 mg/kg by an intraperitoneal injection or budesonide suspension at the dosage of l mg by aerosol inhalation respectively 30 minutes before the OVA challenge. The control and asthma groups were treated with normal saline instead. The concentrations of HIF-1α and VEGF in bronchoalveolar lavage fluid (BALF) were examined using ELISA 24 hours after the last challenge. The pathological changes of lung tissue were observed by hematoxylin-eosin (HE) staining. The p-mTOR and p-4EBP1 from the lung tissues were detected by immunohistochemistry and Western blot. Pearson analysis was used to study the correlation between p-mTOR, p-4EBP1, HIF-1α, and VEGF expression.

RESULTSCompared with the control group, inflammatory cell infiltration and secretions in the trachea increased in the asthma group. The levels of HIF-1α and VEGF in BALF and p-mTOR and p-4EBP1 expression in lung tissues also increased (P<0.01). Compared with the asthma group, inflammatory cell infiltration and secretions in the trachea were reduced in the two intervention groups, and the levels of HIF-1α and VEGF in BALF and p-mTOR and p-4EBP1 expression in lung tissues were also reduced (P<0.01). There were no significant differences in the above changes between the two intervention groups and control group (P>0.05). In the asthma group, there was a pairwise positive correlation between lung p-mTOR and p-4EBP1 expression and HIF-1α and VEGF levels in BALF (P<0.05). However, there were no correlations in the above indexes in the intervention groups and control group.

CONCLUSIONSp-mTOR, p-4EBP1, HIF-1α and VEGF together are involved in the pathogenesis of asthma. Rapamycin treatment can block this signaling pathway, suggesting that this pathway can be used as a novel target for asthma treatment.

Animals ; Asthma ; drug therapy ; metabolism ; Carrier Proteins ; analysis ; physiology ; Female ; Hypoxia-Inducible Factor 1, alpha Subunit ; analysis ; physiology ; Lung ; chemistry ; pathology ; Mice ; Mice, Inbred BALB C ; Phosphoproteins ; analysis ; physiology ; Signal Transduction ; physiology ; TOR Serine-Threonine Kinases ; analysis ; physiology ; Vascular Endothelial Growth Factor A ; analysis ; physiology