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

Serum and glucocorticoid-regulated kinase 1 (SGK1) plays an important role in the physiological processes of hormone release, neuronal excitation and cell proliferation. SGK1 also participates in the pathophysiological processes of inflammation and apoptosis in the central nervous system (CNS). Increasing evidence demonstrates that SGK1 may serve as a target of the intervention of neurodegenerative diseases. In this article, we summarize the recent progress on the role and molecular mechanisms of SGK1 in the regulation of the function of the CNS. We also discuss the potential of newly discovered SGK1 inhibitors in the treatment of CNS diseases.
Humans ; Cell Proliferation ; Central Nervous System Diseases/drug therapy* ; Inflammation ; Protein Serine-Threonine Kinases/physiology*

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

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

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

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

BACKGROUNDTriggering receptor expressed on myeloid cell-1 (TREM-1) may play a vital role in mammalian target of rapamycin (mTOR) modulation of CD8+ T-cell differentiation through the transcription factors T-box expressed in T-cells and eomesodermin during the immune response to invasive pulmonary aspergillosis (IPA). This study aimed to investigate whether the mTOR signaling pathway modulates the proliferation and differentiation of CD8+ T-cells during the immune response to IPA and the role TREM-1 plays in this process.

METHODSCyclophosphamide (CTX) was injected intraperitoneally, and Aspergillus fumigatus spore suspension was inoculated intranasally to establish the immunosuppressed IPA mouse model. After inoculation, rapamycin (2 mg.kg-1.d-1) or interleukin (IL)-12 (5 μg/kg every other day) was given for 7 days. The number of CD8+ effector memory T-cells (Tem), expression of interferon (IFN)-γ, mTOR, and ribosomal protein S6 kinase (S6K), and the levels of IL-6, IL-10, galactomannan (GM), and soluble TREM-1 (sTREM-1) were measured.

RESULTSViable A. fumigatus was cultured from the lung tissue of the inoculated mice. Histological examination indicated greater inflammation, hemorrhage, and lung tissue injury in both IPA and CTX + IPA mice groups. The expression of mTOR and S6K was significantly increased in the CTX + IPA + IL-12 group compared with the control, IPA (P = 0.01; P= 0.001), and CTX + IPA (P = 0.034; P= 0.032) groups, but significantly decreased in the CTX + IPA + RAPA group (P < 0.001). Compared with the CTX + IPA group, the proportion of Tem, expression of IFN-γ, and the level of sTREM-1 were significantly higher after IL-12 treatment (P = 0.024, P= 0.032, and P= 0.017, respectively), and the opposite results were observed when the mTOR pathway was blocked by rapamycin (P < 0.001). Compared with the CTX + IPA and CTX + IPA + RAPA groups, IL-12 treatment increased IL-6 and downregulated IL-10 as well as GM, which strengthened the immune response to the IPA infection.

CONCLUSIONSmTOR modulates CD8+ T-cell differentiation during the immune response to IPA. TREM-1 may play a vital role in signal transduction between mTOR and the downstream immune response.

Animals ; CD8-Positive T-Lymphocytes ; cytology ; metabolism ; Cell Differentiation ; genetics ; physiology ; Female ; Interferon-gamma ; metabolism ; Invasive Pulmonary Aspergillosis ; metabolism ; Lymphocyte Activation ; genetics ; physiology ; Mice ; Mice, Inbred BALB C ; Myeloid Cells ; cytology ; metabolism ; Ribosomal Protein S6 Kinases ; metabolism ; TOR Serine-Threonine Kinases ; genetics ; metabolism ; Tissue Culture Techniques

While several organs in mammals retain partial regenerative capability following tissue damage, the underlying mechanisms remain unclear. Recently, the Hippo signaling pathway, better known for its function in organ size control, has been shown to play a pivotal role in regulating tissue homeostasis and regeneration. Upon tissue injury, the activity of YAP, the major effector of the Hippo pathway, is transiently induced, which in turn promotes expansion of tissue-resident progenitors and facilitates tissue regeneration. In this review, with a general focus on the Hippo pathway, we will discuss its major components, functions in stem cell biology, involvement in tissue regeneration in different organs, and potential strategies for developing Hippo pathway-targeted regenerative medicines.
Adaptor Proteins, Signal Transducing ; metabolism ; Animals ; Homeostasis ; physiology ; Humans ; Phosphoproteins ; metabolism ; Protein-Serine-Threonine Kinases ; metabolism ; Regeneration ; physiology ; Signal Transduction ; physiology

OBJECTIVETo study the association between endoplasmic reticulum stress (ERS) pathway mediated by inositol-requiring kinase 1 (IRE1) and the apoptosis of type II alveolar epithelial cells (AECIIs) exposed to hyperoxia.

METHODSThe primarily cultured AECIIs from preterm rats were devided into an air group and a hyperoxia group. The model of hyperoxia-induced cell injury was established. The cells were harvested at 24, 48, and 72 hours after hyperoxia exposure. An inverted phase-contrast microscope was used to observe morphological changes of the cells. Annexin V/PI double staining flow cytometry was performed to measure cell apoptosis. RT-PCR and Western blot were used to measure the mRNA and protein expression of glucose-regulated protein 78 (GRP78), IRE1, X-box binding protein-1 (XBP-1), and C/EBP homologous protein (CHOP). An immunofluorescence assay was performed to measure the expression of CHOP.

RESULTSOver the time of hyperoxia exposure, the hyperoxia group showed irregular spreading and vacuolization of AECIIs. Compared with the air group, the hyperoxia group showed a significantly increased apoptosis rate of AECIIs and significantly increased mRNA and protein expression of GRP78, IRE1, XBP1, and CHOP compared at all time points (P<0.05). The hyperoxia group had significantly greater fluorescence intensity of CHOP than the air group at all time points. In the hyperoxia group, the protein expression of CHOP was positively correlated with the apoptosis rate of AECIIs and the protein expression of IRE1 and XBP1 (r=0.97, 0.85, and 0.88 respectively; P<0.05).

CONCLUSIONSHyperoxia induces apoptosis of AECIIs possibly through activating the IRE1-XBP1-CHOP pathway.

Animals ; Apoptosis ; Cells, Cultured ; Endoplasmic Reticulum Stress ; physiology ; Endoribonucleases ; physiology ; Epithelial Cells ; physiology ; Female ; Hyperoxia ; metabolism ; pathology ; Multienzyme Complexes ; physiology ; Protein-Serine-Threonine Kinases ; physiology ; Pulmonary Alveoli ; pathology ; Rats ; Rats, Sprague-Dawley ; Transcription Factor CHOP ; physiology ; X-Box Binding Protein 1 ; physiology