OBJECTIVE: To investigate the impacts of sulforaphane (SPN) on cell proliferation and apoptosis in acute promyelogenous leukemia by regulating the PI3K/Akt/mTOR signaling pathway. METHODS: NB4 cells were divided into 5 μmol/L SPN group, 10 μmol/L SPN group, 20 μmol/L SPN group, 740 Y-P (10 μmol/L) group and 20 μmol/L SPN+740 Y-P group, and the untreated NB4 cells were used as the control group. CCK-8, Hoechst 33342 staining, flow cytometry and monodansulfonylpentanediamine (MDC) were used to detect cell proliferation, apoptosis and autophagy, respectively. The expression levels of Bcl-2, Bax, cyclin D1 and LC3B mRNA were detected by qRT-PCR. Western blot was used to detect the expression levels of PI3K/Akt/mTOR pathway-related proteins in NB4 cells. RESULTS: Compared with the control group, the proliferation rate, Bcl-2, cyclin D1 mRNA expressions, p-PI3K/PI3K, p-Akt/Akt, and p-mTOR/mTOR ratio were greatly increased in the 740 Y-P group (P < 0.05), the apoptosis rate, percentage of MDC positive, Bax and LC3B mRNA expression levels were greatly decreased (P < 0.05). The proliferation rate, Bcl-2, cyclin D1 mRNA expression levels, p-PI3K/PI3K, p-Akt/Akt, and p-mTOR/mTOR ratio were greatly decreased in the 5 μmol/L SPN group, 10 μmol/L SPN group, and 20 μmol/L SPN group (P < 0.05), the apoptosis rate, percentage of MDC positive,Bax and LC3B mRNA expression levels were greatly increased, there were differences among different SPN treatment groups (P < 0.05). Compared with the 20 μmol/L SPN group, the proliferation rate, Bcl-2, cyclin D1 mRNA expression levels, p-PI3K/PI3K, p-Akt/Akt, and p-mTOR/mTOR ratio were greatly increased in the 20 μmol/L SPN+740 Y-P group(P < 0.05), the apoptosis rate, percentage of MDC positive, Bax and LC3B mRNA expression levels were greatly decreased (P < 0.05). Compared with the 740 Y-P group, the proliferation rate, Bcl-2, cyclin D1 mRNA expression levels, p-PI3K/PI3K, p-Akt/Akt, and p-mTOR/mTOR ratio in the 20 μmol/L SPN+740 Y-P group were greatly reduced (P < 0.05), the apoptosis rate, percentage of MDC positive, Bax and LC3B mRNA expression levels were greatly increased (P < 0.05). CONCLUSION SPN reduces the proliferation of acute promyelocytic leukemia cells and promotes cells apoptosis by inhibiting the PI3K/Akt/mTOR signaling pathway.
Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Humans ; TOR Serine-Threonine Kinases/metabolism* ; Signal Transduction/drug effects* ; Proto-Oncogene Proteins c-akt/metabolism* ; Isothiocyanates/pharmacology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Sulfoxides ; Cell Line, Tumor ; Cyclin D1/metabolism*

Objective:To investigate the effect of phosphorylated HSP27 on the proliferation and metastasis of nasopharyngeal carcinoma and its molecular mechanism. Methods:①Western blot assay was used to detect the expression levels of HSP27 and p-HSP27 in CNE1 and CNE2 cells of nasopharyngeal carcinoma. Inhibited the phosphorylation of HSP27, Transwell assay detected the metastasis ability of nasopharyngeal carcinoma cells. ②Nasopharyngeal carcinoma cell lines（CNE2-OE1 and CNE2-OE2） overexpressing phosphorylated and dephosphorylated mutants of HSP27 were synthesized, empty vector transfected CNE2 cells（CNE2-NC） were used as controls. The proliferation ability of the three groups of cells was detected by CCK8, and the expression levels of CyclinD1, Bax and Bcl-2 were detected by Western blot. Transwell was used to detect the migration and invasion ability of cells, and Western blot was used to detect the expression levels of E-cadherin, Vimentin, MMP2 and MMP9. Results:The expression level of HSP27 in CNE2 was higher than that of CNE1 cells, while the expression level of p-HSP27 was opposite. After inhibition of HSP27 phosphorylation, the invasion and migration ability of CNE1 cells decreased significantly, with no significant change in CNE2 cells. Compared with CNE2-NC, the growth rate of CNE2-OE1 decreased, and the growth rate of CNE2-OE2 increased. The expression level of CyclinD1 was down-regulated in CNE2-OE1 and higher in CNE2-OE2. The expression level of Bax in CNE2-OE1 was increased, while the expression of Bcl-2 was decreased. There was no significant change in the expression of Bax and Bcl-2 in CNE2-OE2. Compared with CNE2-NC, the migration ability of CNE2-OE1 was enhanced and the invasion ability was weakened, while the migration ability of CNE2-OE2 was weakened and the invasion ability was enhanced. There was no significant difference in the expression levels of E-cadherin was decreased in CNE2-OE1 and increased in CNE2-OE2. There was no significant difference in the expression levels of Vimentin among the three groups. The expression levels of MMP2 and MMP9 were up-regulated in CNE2-OE2, and slightly down-regulated in CNE2-OE1. Conclusion:HSP27 and p-HSP27 were differentially expressed in different nasopharyngeal carcinoma cells, and the metastasis ability of nasopharyngeal carcinoma was not only related to the expression level of HSP27, but also related to the level of p-HSP27. The p-HSP27 inhibited CNE 2 cell proliferation and promoted their apoptosis. As p-HSP27 plays different roles in different stages of nasopharyngeal carcinoma metastasis, it can increase the migration ability of CNE2 cells and reduce its invasion ability. p-HSP27 may induce EMT changes in CNE2 by down-regulating E-cadherin, thus promoting CNE2 migration, and may inhibit CNE2 invasion by down-regulating MMPs expression.
Humans ; Cell Proliferation ; Cell Line, Tumor ; Nasopharyngeal Carcinoma/pathology* ; Nasopharyngeal Neoplasms/pathology* ; Cell Movement ; HSP27 Heat-Shock Proteins/metabolism* ; Phosphorylation ; Neoplasm Metastasis ; Matrix Metalloproteinase 9/metabolism* ; Neoplasm Invasiveness ; Matrix Metalloproteinase 2/metabolism* ; Heat-Shock Proteins/metabolism* ; Cyclin D1/metabolism* ; Molecular Chaperones/metabolism* ; Cadherins/metabolism*

Objective To investigate the expression level of serine/threonine phosphoprotein phosphatase 4C(PPP4C)in gastric cancer,and analyze its relationship with prognosis and the underlying regulatory mechanism.Methods The clinical data of 104 gastric cancer patients admitted to the First Affiliated Hospital of Bengbu Medical College between January 2012 and August 2016 were collected.Immunohistochemical staining was employed to determine the expression levels of PPP4C and Ki-67 in the gastric cancer tissue.The gastric cancer cell lines BGC823 and HGC27 were cultured and transfected with the vector for PPP4C knockdown,the vector for PPP4C overexpression,and the lentiviral vector(control),respectively.The effects of PPP4C on the cell cycle and proliferation were analyzed and the possible regulatory mechanisms were explored.Results PPP4C was highly expressed in gastric cancer(P<0.001),and its expression promoted malignant progression of the tumor(all P<0.01).Univariate and Cox multivariate analysis clarified that high expression of PPP4C was an independent risk factor affecting the 5-year survival rate of gastric cancer patients(P=0.003).Gene ontology and Kyoto encyclopedia of genes and genomes enrichment analysis suggested that PPP4C may be involved in the cell cycle.The correlation analysis showed that the expression of PPP4C was positively correlated with that of Ki-67 in gastric cancer(P<0.001).The up-regulation of PPP4C expression increased the proportion of tumor cells in the S phase,alleviated the G2/M phase arrest,and promoted the proliferation of gastric cancer cells and the expression of cyclin D1 and cyclin-dependent kinase 6(CDK6)(all P<0.05).The down-regulation of PPP4C decreased the proportion of gastric cancer cells in the S phase,promoted G2/M phase arrest,and inhibited cell proliferation and the expression of cyclin D1,CDK6,and p53(all P<0.05).p53 inhibitors promoted the proliferation of BGC823 and HGC27 cells in the PPP4C knockdown group(P<0.001,P<0.001),while p53 activators inhibited the proliferation of BGC823 and HGC27 cells in the PPP4C overexpression group(P<0.001,P=0.002).Conclusions PPP4C is highly expressed in gastric cancer and affects the prognosis of the patients.It may increase the proportion of gastric cancer cells in the S phase and alleviate the G2/M phase arrest by inhibiting p53 signaling,thereby promoting cell proliferation.
Humans ; Stomach Neoplasms/genetics* ; Cyclin D1/metabolism* ; Tumor Suppressor Protein p53 ; Phosphoproteins/metabolism* ; Ki-67 Antigen ; Cell Line, Tumor ; Prognosis ; Cell Proliferation ; Phosphoprotein Phosphatases/metabolism* ; Threonine ; Serine

OBJECTIVE: To explore the mechanism of Radix Scrophulariae (RS) extracts in the treatment of hyperthyroidism rats by regulating proliferation, apoptosis, and autophagy of thyroid cell through the mammalian sterile 20-like kinase 1 (MST1)/Hippo pathway. METHODS: Twenty-four rats were randomly divided into 4 groups according to a random number table: control, model group, RS, and RS+Hippo inhibitor (XMU-MP-1) groups (n=6 per group). Rats were gavaged with levothyroxine sodium tablet suspension (LST, 8 μ g/kg) for 21 days except for the control group. Afterwards, rats in the RS group were gavaged with RS extracts at the dose of 1,350 mg/kg, and rats in the RS+XMU-MP-1 group were gavaged with 1,350 mg/kg RS extracts and 1 mg/kg XMU-MP-1. After 15 days of administration, thyroid gland was taken for gross observation, and histopathological changes were observed by hematoxylin-eosin staining. The structure of Golgi secretory vesicles in thyroid tissues was observed by transmission electron microscopy. The expression of thyrotropin receptor (TSH-R) was observed by immunohistochemistry. Terminal-deoxynucleoitidyl transferase mediated nick end labeling assay was used to detect cell apoptosis in thyroid tissues. Real-time quantity primer chain reaction and Western blot were used to detect the expressions of MST1, p-large tumor suppressor gene 1 (LATS1), p-Yes1 associated transcriptional regulator (YAP), proliferating cell nuclear antigen (PCNA), G₁/S-specific cyclin-D1 (Cyclin D1), B-cell lymphoma-2 (Bcl-2), Caspase-3, microtubule-associated proeins light chain 3 II/I (LC3-II/I), and recombinant human autophagy related 5 (ATG5). Thyroxine (T4) level was detected by enzyme-linked immunosorbent assay. RESULTS: The thyroid volume of rats in the model group was significantly increased compared to the normal control group (P<0.01), and pathological changes such as uneven size of follicular epithelial cells, disorderly arrangement, and irregular morphology occurred. The secretion of small vesicles by Golgi apparatus was reduced, and the expressions of receptor protein TSH-R and T4 were significantly increased (P<0.01), while the expressions of MST1, p-LATS1, p-YAP, Caspase-3, LC3-II/I, and ATG5 were significantly decreased (P<0.01). The expressions of Bcl-2, PCNA, and cyclin D1 were significantly increased (P<0.01). Compared with the model group, RS extracts reduced the volume of thyroid gland, improved pathological condition of the thyroid gland, promoted secretion of the secretory vesicles with double-layer membrane structure in thyroid Golgi, significantly inhibited the expression of TSH-R and T4 levels (P<0.01), upregulated MST1, p-LATS1, p-YAP, Caspase-3, LC3-II/I, and ATG5 expressions (P<0.01), and downregulated Bcl-2, PCNA, and Cyclin D1 expressions (P<0.01). XMU-MP-1 inhibited the intervention effects of RS extracts (P<0.01). CONCLUSION RS extracts could inhibit proliferation and promote apoptosis and autophagy in thyroid tissues through MST1/Hippo pathway for treating hyperthyroidism.
Rats ; Humans ; Animals ; Hippo Signaling Pathway ; Proliferating Cell Nuclear Antigen/metabolism* ; Cyclin D1/pharmacology* ; Caspase 3/metabolism* ; Protein Serine-Threonine Kinases/pharmacology* ; Apoptosis ; Hyperthyroidism/drug therapy* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Thyrotropin/pharmacology* ; Mammals/metabolism*

This study aimed to observe the effect of terpinen-4-ol(T4O) on the proliferation of vascular smooth muscle cells(VSMCs) exposed to high glucose(HG) and reveal the mechanism via the Krüppel-like factor 4(KLF4)/nuclear factor kappaB(NF-κB) signaling pathway. The VSMCs were first incubated with T4O for 2 h and then cultured with HG for 48 h to establish the model of inflammatory injury. The proliferation, cell cycle, and migration rate of VSMCs were examined by MTT method, flow cytometry, and wound healing assay, respectively. The content of inflammatory cytokines including interleukin(IL)-6 and tumor necrosis factor-alpha(TNF-α) in the supernatant of VSMCs was measured by enzyme-linked immunosorbent assay(ELISA). Western blot was employed to determine the protein levels of proliferating cell nuclear antigen(PCNA), Cyclin D1, KLF4, NF-κB p-p65/NF-κB p65, IL-1β, and IL-18. The KLF4 expression in VSMCs was silenced by the siRNA technology, and then the effects of T4O on the cell cycle and protein expression of the HG-induced VSMCs were observed. The results showed that different doses of T4O inhibited the HG-induced proliferation and migration of VSMCs, increased the percentage of cells in G_1 phase, and decreased the percentage of cells in S phase, and down-regulated the protein levels of PCNA and Cyclin D1. In addition, T4O reduced the HG-induced secretion and release of the inflammatory cytokines IL-6 and TNF-α and down-regulated the expression of KLF4, NF-κB p-p65/NF-κB p65, IL-1β, and IL-18. Compared with si-NC+HG, siKLF4+HG increased the percentage of cells in G_1 phase, decreased the percentage of cells in S phase, down-regulated the expression of PCNA, Cyclin D1, and KLF4, and inhibited the activation of NF-κB signaling pathway. Notably, the combination of silencing KLF4 with T4O treatment further promoted the changes in the above indicators. The results indicate that T4O may inhibit the HG-induced proliferation and migration of VSMCs by down-regulating the level of KLF4 and inhibiting the activation of NF-κB signaling pathway.
NF-kappa B/metabolism* ; Interleukin-18/metabolism* ; Proliferating Cell Nuclear Antigen/genetics* ; Cyclin D1/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Muscle, Smooth, Vascular ; Cell Proliferation ; Signal Transduction ; Cytokines/metabolism* ; Glucose/metabolism*

This study aims to investigate mechanism of "Ephedrae Herba-Descurainiae Semen Lepidii Semen" combination(MT) in the treatment of bronchial asthma based on network pharmacology and in vivo experiment, which is expected to lay a theoretical basis for clinical application of the combination. First, the potential targets of MT in the treatment of bronchial asthma were predicted based on network pharmacology, and the "Chinese medicine-active component-target-pathway-disease" network was constructed, followed by Gene Oncology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment of the potential targets. Molecular docking was used to determine the binding activity of key candidate active components to hub genes. Ovalbumin(OVA, intraperitoneal injection for sensitization and nebulization for excitation) was used to induce bronchial asthma in rats. Rats were classified into control group(CON), model group(M), dexamethasone group(DEX, 0.075 mg·kg~(-1)), and MT(1∶1.5) group. Hematoxylin and eosin(HE), Masson, and periodic acid-Schiff(PAS) staining were performed to observe the effect of MT on pathological changes of lungs and trachea and goblet cell proliferation in asthma rats. The levels of transforming growth factor(TGF)-β1, interleukin(IL)6, and IL10 in rat serum were detected by enzyme-linked immunosorbent assay(ELISA), and the mRNA and protein levels of mitogen-activated protein kinase 8(MAPK8), cyclin D1(CCND1), IL6, epidermal growth factor receptor(EGFR), phosphatidylinositol 3-kinase(PI3 K), and protein kinase B(Akt) by qRT-PCR and Western blot. Network pharmacology predicted that MAPK8, CCND1, IL6, and EGFR were the potential targets of MT in the treatment of asthma, which may be related to PI3 K/Akt signaling pathway. Quercetin and β-sitosterol in MT acted on a lot of targets related to asthma, and molecular docking results showed that quercetin and β-sitosterol had strong binding activity to MAPK, PI3 K, and Akt. In vivo experiment showed that MT could effectively alleviate the symptoms of OVA-induced asthma rats, improve the pathological changes of lung tissue, reduce the production of goblet cells, inhibit the inflammatory response of asthma rats, suppress the expression of MAPK8, CCND1, IL6, and EGFR, and regulate the PI3 K/Akt signaling pathway. Therefore, MT may relieve the symptoms and inhibit inflammation of asthma rats by regulating the PI3 K/Akt signaling pathway, and quercetin and β-sitosterol are the candidate active components.
Animals ; Asthma/drug therapy* ; Cyclin D1 ; Dexamethasone/adverse effects* ; Drug Combinations ; Drugs, Chinese Herbal/therapeutic use* ; Eosine Yellowish-(YS)/adverse effects* ; Ephedra ; ErbB Receptors ; Hematoxylin/therapeutic use* ; Interleukin-10 ; Interleukin-6 ; Mitogen-Activated Protein Kinase 8/therapeutic use* ; Molecular Docking Simulation ; Network Pharmacology ; Ovalbumin/adverse effects* ; Periodic Acid/adverse effects* ; Phosphatidylinositol 3-Kinases ; Proto-Oncogene Proteins c-akt/metabolism* ; Quercetin ; RNA, Messenger ; Rats

OBJECTIVE: To explore the role of miR-744-5p/CCND1 axis in clear-cell renal cell carcinoma (ccRCC). METHODS: We examined the expression levels of miR-744-5p in 65 pairs of ccRCC and adjacent tissue specimens and in 5 ccRCC cell lines and human renal tubular epithelial (HK2) cells using qRT-PCR. The ccRCC cell lines 786-O and OSRC2 were transfected with miR-744-5p mimic, CCND1 mimic, or their negative control mimics, and the changes in cell proliferation, migration, and invasion were evaluated with CCK-8, wound healing, and Transwell assays. The downstream target molecules of miR-744-5p were predicted by bioinformatics analysis, and the expression level of CCND1 in ccRCC cells was verified by qRT-PCR and Western blotting. The relationship between miR-744-5p and CCND1 was further validated by dual luciferase reporter assay, and the role of the miR-744-5p/CCND1 axis in ccRCC was explored by rescue experiments. RESULTS: MiR-744-5p was significantly downregulated in ccRCC tissues and cell lines (all P < 0.05), and its overexpression inhibited the proliferation, migration, and invasion of ccRCC cells (all P < 0.05). Bioinformatics analysis and dual luciferase reporter assay showed that CCND1 was a downstream target of miR-744-5p. The results of rescue experiments showed that upregulation of CCND1 could partially reverse the inhibitory effect of miR-744-5p overexpression on ccRCC cell proliferation, migration, and invasion (all P < 0.05). CONCLUSION MiR-744-5p inhibits the malignant phenotype of ccRCC cells by targeting CCND1, and the miR-744-5p/CCND1 axis may be a novel target for diagnosis and treatment of ccRCC.
Carcinoma, Renal Cell/metabolism* ; Cell Line, Tumor ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Cyclin D1/genetics* ; Humans ; Kidney Neoplasms/metabolism* ; MicroRNAs/metabolism*

OBJECTIVE: To explore the mechanisms underlying the proliferative inhibition of Chinese herbal medicine Kang-Ai injection (KAI) in gastric cancer cells. METHODS: Gastric cancer cell lines MGC803 and BGC823 were treated by 0, 0.3%, 1%, 3% and 10% KAI for 24, 48 and 72 h, respectively. The cell proliferation was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The apoptosis and cell cycle were evaluated by flow cytometry. Interleukin (IL)-6 mRNA and protein expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immune sorbent assay (ELISA), respectively. The protein expression levels of cyclin A, cyclin E, cyclin B1, cyclin D1, p21, retinoblastoma (RB), protein kinase B (AKT), extracellular regulated protein kinases (ERK), signal transducer and activator of transcription (STAT) 1 and STAT3 were detected by Western blot. RESULTS: KAI inhibited the proliferation of MGC803 and BGC823 gastric cancer cells in dose- and time-dependent manner. After treated with KAI for 48 h, the proportion of G1 phase was increased, expression level of cyclin D1 and phosphorylation-RB were down-regulated, whereas the expression of p21 was up-regulated (all P<0.01). Furthermore, 48-h treatment with KAI decreased the phosphorylation level of STAT3, inhibited the mRNA and protein expressions of IL-6 (all P<0.01). IL-6 at dose of 10 ng/mL significantly attenuated the proliferative effect of both 3% and 10% KAI, and recovered KAI-inhibited STAT3 phosphorylation and cyclin D1 expression level (all P<0.01). CONCLUSION KAI exerted an anti-proliferative function by inhibiting IL-6/STAT3 signaling pathway followed by the induction of G₁ phase arrest in gastric cancer cells.
Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Cyclin D1/pharmacology* ; Humans ; Interleukin-6/metabolism* ; RNA, Messenger/metabolism* ; STAT3 Transcription Factor/metabolism* ; Stomach Neoplasms/genetics*

OBJECTIVE: To investigate the effect of Chaihu Guizhi Decoction (CHGZD) combined with capecitabine on growth and apoptosis of subcutaneous triple-negative breast cancer xenografts in nude mice and explore the possible mechanism. METHODS: Nude mouse models bearing subcutaneous triple-negative breast cancer xenografts were randomized into 6 groups (n=10) for treatment with distilled water (model group), low (10.62 g/kg), medium (21.23 g/kg) and high (42.46 g/kg) doses of CHGZD, capecitabine (0.2 mg/kg), or the combination of CHGZD (42.46 g/kg) and capecitabine (0.2 mg/k) once daily for 21 consecutive days. The general condition of mice was observed, and after 21-day treatments, the tumors were dissected for measurement of tumor volume and weight and histopathological examination with HE staining. Serum IL-6 levels of the mice were determined with enzyme-linked immunosorbent assay (ELISA), and the expression levels of IL-6, STAT3, p-STAT3, Bax, Bcl-2 and cyclin D1 in the tumor tissues were detected using real-time PCR and Western blotting. RESULTS: Compared with those in the model group, the tumor-bearing mice receiving treatments with CHGZD showed significantly increased food intake with good general condition, sensitive responses, increased body weight, and lower tumor mass (P < 0.01). Compared with capecitabine treatment alone, treatment with CHGZD alone at the medium and high doses and the combined treatment all resulted in significantly higher tumor inhibition rates (P < 0.01), induced obvious tumor tissue degeneration and reduced the tumor cell density. Treatments with CHGZD, both alone and in combination with capecitabine, significantly decreased serum IL-6 level, lowered the mRNA expression levels of IL-6 and STAT3, the protein expressions of IL-6, STAT3 and P-STAT3 (P < 0.05), and the mRNA and protein expressions of Bcl-2 and cyclin D1 (P < 0.05), and increased the mRNA and protein expressions of Bax in the tumor tissues (P < 0.05). CONCLUSION CHGZD combined with capecitabine can significantly inhibit tumor growth in nude mice bearing triple-negative breast cancer xenografts, the mechanism of which may involve the inhibition of IL-6/STAT3 signaling pathway and regulation of Bax, Bcl-2 and cyclin D1 expressions to suppress tumor cell proliferation and differentiation and induce cell apoptosis.
Animals ; Capecitabine/pharmacology* ; Cyclin D1/metabolism* ; Drugs, Chinese Herbal ; Heterografts ; Humans ; Interleukin-6/metabolism* ; Mice ; Mice, Nude ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; RNA, Messenger/metabolism* ; STAT3 Transcription Factor/metabolism* ; Signal Transduction ; Triple Negative Breast Neoplasms/drug therapy* ; bcl-2-Associated X Protein/metabolism*

OBJECTIVE: The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a persistent organic pollutant, is harmful to the nervous system, but its effects on the brain are still unclear. This study aimed to investigate the effects of TCDD on astrocytes proliferation and underlying molecular mechanism. METHODS: The cell proliferation was measured by EdU-based proliferation assay and PI staining by flow cytometry. Protein expression levels were detected by Western blotting. Immunofluorescence, cytoplasmic and nuclear fractions separation were used to assess the distribution of signal transducer and activator of transcription 3 (STAT3). RESULTS: C6 cells treated with 10 and 50 nmol/L TCDD for 24 h showed significant promotion of the proliferation of. The exposure to TCDD resulted in the upregulation in the expression levels of phosphorylated protein kinase B (p-Akt), phosphorylated STAT3, and cyclin D1 in a dose- and time-dependent manner. The inhibition of Akt expression with LY294002 or STAT3 expression with AG490 abolished the TCDD-induced cyclin D1 upregulation and cell proliferation. Furthermore, LY294002 suppressed the activation of STAT3. Finally, TCDD promoted the translocation of STAT3 from the cytoplasm to the nucleus, and LY294002 treatment blocked this effect. CONCLUSION TCDD exposure promotes the proliferation of astrocyte cells via the Akt/STAT3/cyclin D1 pathway, leading to astrogliosis.
Animals ; Animals, Newborn ; Astrocytes ; drug effects ; Cell Proliferation ; drug effects ; Cyclin D1 ; metabolism ; Environmental Pollutants ; toxicity ; Neurotoxins ; toxicity ; Polychlorinated Dibenzodioxins ; toxicity ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats, Sprague-Dawley ; STAT3 Transcription Factor ; metabolism