Objective To explore the mechanism of lncRNA-BC200 (BC200) targeting the ubiquitination of Beta-site APP cleaving enzyme 1 (BACE1) and regulating the repair of nerve cell injury. Methods Mouse hippocampal neuron cell line HT22 was divided into four groups: control group, oxygen-glucose deprivation/reoxygenation(OGD/R) group, OGD/R+si-NC group and OGD/R+si-BC200 group. In order to further explore the relationship between BC200 and BACE1, HT22 cells were divided into four groups: OGD/R group, OGD/R+si-BC200 group, OGD/R+si-BC200+NC group and OGD/R+si-BC200+ BACE1 group. Twenty male C57BL/6J mice were randomly assigned to the following four groups: control group, middle cerebral artery occlusion (MCAO) group, MCAO+si-BC200 group and MCAO+si-BC200+BACE1 group. The mRNA expression levels of BC200 and BACE1 in cells were measured by real-time quantitative reverse transcription polymerase chain reaction. The expressions of c-caspase-3, B-cell lymphoma 2 (Bcl2), Bcl2 associated X protein(BAX) and BACE1 were detected by western blot, and the apoptotic cells were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) test. Results Compared with the control group, the activity of HT22 cells in OGD/R group decreased significantly, and the percentage of apoptotic cells increased significantly. Compared with OGD/R+si-NC group, the activity of HT22 cells in OGD/R+si-BC200 group increased significantly, and the percentage of apoptotic cells decreased significantly. Compared with the control group, the expression of BACE1 protein in HT22 cells in OGD/R group was significantly enhanced. Compared with OGD/R+si-NC group, the expression of BACE1 protein in HT22 cells in OGD/R+si-BC200 group decreased significantly. It was observed that after OGD/R treatment, the ubiquitination level of BACE1 decreased significantly and the expression of BACE1 protein increased significantly. After transfection with si-BC200, the ubiquitination level of BACE1 protein increased significantly, while the expression of BACE1 protein decreased significantly. Compared with OGD/R+si-BC200+NC group, the percentage of apoptotic cells, the expression of c-caspase-3 and Bax protein in HT22 cells in OGD/R+si-BC200+BACE1 group increased significantly, and the expression of Bcl2 protein decreased significantly. Compared with the control group, the number of cerebral infarction areas and TUNEL positive cells in MCAO group increased significantly, and the survival number of neurons decreased significantly. Compared with the MCAO group, the number of cerebral infarction areas and TUNEL positive cells in MCAO+si-BC200 group decreased significantly, and the survival number of neurons increased significantly, while the addition of BACE1 reversed the improvement of si-BC200 transfection. Conclusion The combination of BC200 and BACE1 inhibit the ubiquitination of BACE1, and participate in mediating the expression enhancement of BACE1 induced by OGD/R. Specific blocking of BC200/BACE1 axis may be a potential therapeutic target to protect neurons from apoptosis induced by cerebral ischemia/reperfusion.
Animals ; Amyloid Precursor Protein Secretases/genetics* ; RNA, Long Noncoding/physiology* ; Aspartic Acid Endopeptidases/genetics* ; Male ; Neurons/pathology* ; Mice ; Mice, Inbred C57BL ; Apoptosis/genetics* ; Ubiquitination ; Cell Line ; Hippocampus/metabolism* ; bcl-2-Associated X Protein/genetics* ; Caspase 3/genetics* ; Infarction, Middle Cerebral Artery/metabolism*

OBJECTIVES: To explore the mechanism by which histone deacetylase 1 (HDAC1) regulates steroid-induced apoptosis of mouse osteocyte-like MLO-Y4 cells. METHODS: MLY-O4 cells were treated with 400 nmol/L trichostatin A (TSA) or 1 mmol/L dexamethasone for 24 h or transfected with a HDAC1-overexpressing vector prior to TSA or dexamethasone treatment. The changes in the expressions of HDAC1, SP1, cleaved caspase-3 and Bax, SP1 acetylation level, cell proliferation, and cell apoptosis were examined. The interaction between HDAC1 and SP1 was determined with immunoprecipitation assay and Western blotting. RESULTS: Treatment with dexamethasone significantly increased cell apoptosis, enhanced the expressions of cleaved caspase-3 and Bax, reduced HDAC1 expression, and suppressed proliferation of MLO-Y4 cells. Both TSA and dexamethasone obviously increased SP1 acetylation level and the expression of SP1 in MLO-Y4 cells. HDAC1 overexpression in the cells significantly attenuated the effect of TSA and dexamethasone, promoted cell proliferation, lowered the expressions of SP1, cleaved caspase-3 and Bax, and inhibited dexamethasone-induced cell apoptosis. Immunoprecipitation assay and Western blotting demonstrated the interaction between HDAC1 and SP1 in the cells. CONCLUSIONS HDAC1 inhibits dexamethasone-induced apoptosis and promotes proliferation of cultured mouse osteocytes by suppressing SP1 expression via promoting its deacetylation.
Animals ; Apoptosis/drug effects* ; Mice ; Histone Deacetylase 1/genetics* ; Osteocytes/drug effects* ; Sp1 Transcription Factor/metabolism* ; Acetylation ; Dexamethasone/pharmacology* ; Cell Proliferation/drug effects* ; Caspase 3/metabolism* ; Cell Line ; Hydroxamic Acids/pharmacology* ; bcl-2-Associated X Protein/metabolism*

OBJECTIVES: To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress. METHODS: Twenty male SD rats were randomized equally into control group and heat stress group. After exposure to 32 ℃ for 2 weeks in the latter group, the rats were examined for histopathological changes and Bmal1 expression in the thoracic aorta using HE staining and immunohistochemistry. In the cell experiments, cultured rat thoracic aortic endothelial cells (RTAECs) were incubated at 40 ℃ for 12 h with or without prior transfection with a Bmal1-specific small interfering RNA (si-Bmal1) or a negative sequence. In both rat thoracic aorta and RTAECs, the expressions of Bmal1, the cell cycle proteins CDK1, CDK4, CDK6, and cyclin B1, and apoptosis-related proteins Bax and Bcl-2 were detected using Western blotting. TUNEL staining was used to detect cell apoptosis in rat thoracic aorta, and the changes in cell cycle distribution and apoptosis in RTAECs were analyzed with flow cytometry. RESULTS: Compared with the control rats, the rats exposed to heat stress showed significantly increased blood pressures and lowered heart rate with elastic fiber disruption and increased expressions of Bmal1, cyclin B1 and CDK1 in the thoracic aorta (P<0.05). In cultured RTAECs, heat stress caused significant increase of Bmal1, cyclin B1 and CDK1 protein expression levels, which were obviously lowered in cells with prior si-Bmal1 transfection. Bmal1 knockdown also inhibited heat stress-induced increase of apoptosis in RTAECs as evidenced by decreased expression of Bax and increased expression of Bcl-2. CONCLUSIONS Heat stress upregulates Bmal1 expression and causes alterations in expressions of cyclins to trigger apoptosis of rat thoracic aorta endothelial cells, which can be partly alleviated by suppressing Bmal1 expression.
Animals ; ARNTL Transcription Factors/genetics* ; Male ; Aorta, Thoracic/metabolism* ; Rats ; Rats, Sprague-Dawley ; Endothelial Cells/metabolism* ; Apoptosis ; Cells, Cultured ; Heat-Shock Response ; Cyclin B1/metabolism* ; CDC2 Protein Kinase/metabolism* ; Cyclins/metabolism* ; RNA, Small Interfering ; bcl-2-Associated X Protein/metabolism*

OBJECTIVE: To observe the effects of the "Zhibian" (BL54)-toward-"Shuidao" (ST28) acupuncture on key regulatory factors during mitochondrial apoptosis of testicular tissue in asthenozoospermia mice, and explore the potential mechanism of the protective effect of acupuncture on reproductive function. METHODS: Thirty C57BL/6 male mice were randomly divided into a blank group, a model group and an acupuncture group, 10 mice in each group. In the model and the acupuncture groups, the intraperitoneal injection of cyclophosphamide (30 mg•kg^-1•d^-1) was delivered for 7 days to prepare the asthenozoospermia model. After the success of modeling, the modeled mice in the acupuncture group were intervened with "Zhibian" (BL54)-toward-"Shuidao" (ST28) acupuncture, once daily and the needles were retained for 20 min. The duration of the intervention was 2 weeks. The general condition of each mouse was observed, and the body mass was recorded before modeling, after modeling and after intervention completion. After intervention, the testicular mass was recorded and the weight coefficient was calculated, and the mouse sperm quality was examined; the serum contents of testosterone (T), follicle stimulating hormone (FSH) and luteinizing hormone (LH) were detected using ELISA, the morphology of testicular tissue was observed using HE, the mitochondrial ultra-microstructure of testicular tissue was observed under transmission electrone microscopy, the mitochondrial membrane potential level of testicular tissue was detected using JC-1 staining, the positive rate of apoptosis cell of testicular tissue was observed using TUNEL; and the mRNA and protein expression of b-cell lymphocytoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), cytochrome c (Cyt C), apoptotic protease-activating factor1 (Apaf-1), Caspase-9 and Caspase-3 of testicular tissue was detected using real-time quantitative fluorescence PCR and Western blot methods separately; and the positive expression of Cleaved Caspase-3 of the testicular tissue was detected using immunohistochemistry. RESULTS: Compared with the blank group, the mice were in listless spirits, had shaggy hairs, the reduced appetite and movement, and weight loss in the model group (P<0.01); the testicular mass and the weight coefficient decreased (P<0.01); the total number of sperms, sperm motility, and sperm viability were declined (P<0.01); while the levels of serum T, FSH, and LH were dropped (P<0.01). The morphology of seminiferous tubules in testicular tissue was abnormal, the number of spermatogenic cells and the number of mitochondria decreased, the inner mitochondrial crest was fractured and lost, and vacuoles appeared. The level of mitochondrial membrane potential was reduced (P<0.01); and the positive rate of apoptosis cell in testicular tissue increased (P<0.01). The mRNA and protein expression of Bax, Cyt C, Apaf-1, Caspase-9 and Caspase-3 was elevated (P<0.01, P<0.05), the mRNA and protein expression of Bcl-2 was dropped (P<0.01), and the average absorbance value of Cleaved Caspase-3 increased (P<0.01). When compared with the model group, in the acupuncture group, the general condition of mice was improved, the testicular mass and the weight coefficient elevated (P<0.01); the total number of sperms, sperm motility, and sperm viability increased (P<0.01); while the levels of serum T, FSH, and LH rose (P<0.01). The pathological morphology of testicular tissue and the inner mitochondrial ultra-microstructure were ameliorated, the level of mitochondrial membrane potential was elevated (P<0.01); the positive rate of apoptosis cell was reduced (P<0.01). The mRNA and protein expression of Bax, Cyt C, Apaf-1, Caspase-9 and Caspase-3 was dropped (P<0.01, P<0.05), the mRNA and protein expression of Bcl-2 elevated (P<0.05), and the average absorbance value of Cleaved Caspase-3 declined (P<0.01). CONCLUSION "Zhibian" (BL54)-toward- "Shuidao" (ST28) acupuncture may ameliorate mouse reproductive function by inhibiting mitochondrial apoptosis pathway, alleviating testicular tissue damage in the asthenospermia mice induced by cyclophosphamide.
Animals ; Male ; Mice ; Apoptosis ; Acupuncture Therapy ; Mitochondria/metabolism* ; Asthenozoospermia/genetics* ; Humans ; Testis/metabolism* ; Mice, Inbred C57BL ; Spermatozoa/metabolism* ; Acupuncture Points ; Sperm Motility ; Testosterone/blood* ; Proto-Oncogene Proteins c-bcl-2/genetics* ; Caspase 3/genetics* ; Follicle Stimulating Hormone/blood* ; Reproduction ; Cytochromes c/genetics* ; bcl-2-Associated X Protein/genetics* ; Apoptotic Protease-Activating Factor 1/genetics*

This study aims to elucidate the role and mechanism of clematichinenoside AR(CAR) in protecting bone marrow mesenchymal stem cells(BMSCs) from hypoxia-induced apoptosis. BMSCs were isolated by the bone fragment method and identified by flow cytometry. Cells were cultured under normal conditions(37℃, 5% CO_2) and hypoxic conditions(37℃, 90% N_2, 5% CO_2) and treated with CAR. The BMSCs were classified into eight groups: control(normal conditions), CAR(normal conditions + CAR), hypoxia 24 h, hypoxia 24 h + CAR, hypoxia 48 h, hypoxia 48 h + CAR, hypoxia 72 h, and hypoxia 72 h + CAR. The cell counting kit-8(CCK-8) assay and terminal-deoxynucleoitidyl transferase mediated nick end labeling(TUNEL) were employed to measure cell proliferation and apoptosis, respectively. The number of mitochondria and mitochondrial membrane potential were measured by MitoTracker®Red CM-H2XRo staining and JC-1 staining, respectively. The level of reactive oxygen species(ROS) was measured with the DCFH-DA fluorescence probe. The protein levels of B-cell lymphoma-2 associated X protein(BAX), caspase-3, and optic atrophy 1(OPA1) were determined by Western blot. The results demonstrated that CAR significantly increased cell proliferation. Compared with the control group, the hypoxia groups showed increased apoptosis rates, reduced mitochondria, elevated ROS levels, decreased mitochondrial membrane potential, upregulated expression of BAX and caspase-3, and downregulated expression of OPA1. In comparison to the corresponding hypoxia groups, CAR intervention significantly decreased the apoptosis rate, increased mitochondria, reduced ROS levels, elevated mitochondrial membrane potential, downregulated the expression of BAX and caspase-3, and upregulated the expression of OPA1. Therefore, it can be concluded that CAR may exert an anti-apoptotic effect on BMSCs under hypoxic conditions by regulating OPA1 to maintain mitochondrial homeostasis.
Mesenchymal Stem Cells/metabolism* ; Apoptosis/drug effects* ; Mitochondria/metabolism* ; Animals ; Rats ; Cell Hypoxia/drug effects* ; Homeostasis/drug effects* ; Reactive Oxygen Species/metabolism* ; Rats, Sprague-Dawley ; Membrane Potential, Mitochondrial/drug effects* ; Saponins/pharmacology* ; Caspase 3/genetics* ; Male ; bcl-2-Associated X Protein/genetics* ; Bone Marrow Cells/metabolism* ; Cell Proliferation/drug effects* ; Protective Agents/pharmacology* ; Cells, Cultured

The Chinese hamster ovary (CHO) cell is the most representative mammalian cell protein expression system, and it is widely used in recombinant protein, vaccine and other biopharmaceutical fields. However, due to its vulnerability to environmental factors, apoptosis, and metabolic inhibitors, CHO cells demonstrate poor robustness, and thus the integrated viable cell density and unit cell productivity are largely limited. To improve the robustness and foreign protein expression efficiency of CHO cells, we employed CRISPR/Cas9 to knock out the apoptosis genes Bax and Bak and the lactate dehydrogenase gene LDHa, thereby blocking apoptosis and lactic acid metabolism pathways. The results of apoptosis and single cell viability detection showed that the number of apoptotic cells in the knockout cell lines Bax^-/-, Bax-bak^-/-, and LDHa-Bax-bak^-/- was reduced by 22.51%, 37.73%, and 64.12%, respectively, compared with the wild-type cell line CHO-K1, which indicated that the anti-apoptotic ability was significantly improved. After staurosporine treatment, the single cell viability of Bax^-/-, Bax-bak^-/-, and LDHa-Bax-bak^-/- cells was increased by 30.8%, 22%, and 41.1%, respectively. After treatment with puromycin, the single cell viability of Bax^-/-, Bax-bak^-/-, and LDHa-Bax-bak^-/- cells was increased by 26.7%, 30.7%, and 38.8%, respectively. To further investigate the production performance of cells obtained after blocking apoptosis and lactic acid metabolism pathways, we induced transient expression of human tissue plasminogen activator (tPA) in these cells. The results showed that the secretion of tPA in Bax^-/-, Bax-Bak^-/-, and LDHa-Bax-Bak^-/- cells was 11.12%, 46.18%, and 63.13%, respectively, higher than that in wild-type CHO-K1 cells. The expression of intracellular tPA was increased by 35.65%, 130%, and 192.15%. In conclusion, blocking apoptosis and lactic acid metabolism pathways simultaneously can improve cell robustness and productivity, with the performance better than blocking the apoptosis pathway alone. The above results indicated that the constructed cell lines were expected to be the delivery carriers of protein drugs such as medicinal peptides, and better used for the treatment of diseases.
CHO Cells ; Cricetulus ; Animals ; Apoptosis/genetics* ; Lactic Acid/metabolism* ; Recombinant Proteins/biosynthesis* ; L-Lactate Dehydrogenase/genetics* ; bcl-2-Associated X Protein/genetics* ; bcl-2 Homologous Antagonist-Killer Protein/genetics* ; Cricetinae ; CRISPR-Cas Systems ; Staurosporine/pharmacology*

This study aims to explore the effect and mechanism of Danggui Buxue Decoction(DBD)-containing serum in alleviating the H9c2 cell injury caused by the exposure to intermittent low oxygen. H9c2 cells were assigned into five groups: control(CON) group, intermittent low oxygen(IH) group, intermittent low oxygen plus DBD-containing serum(IH+DBD) group, intermittent low oxygen plus the autophagy enhancer rapamycin(IH+RAPA) group, and intermittent low oxygen plus DBD-containing serum and the autophagy inhibitor 3-methyladenine(IH+DBD+3-MA) group. Monodansylcadaverine(MDC) staining was employed to detect the changes of autophagosomes. Cell counting kit-8(CCK-8) assay was employed to determine the activity of myocardial cells, and lactate dehydrogenase(LDH) and creatine kinase(CK) kits were used to measure the LDH and CK levels in the cell culture, which would reflect the degree of cell damage. TdT-mediated dUTP nick-end labeling(TUNEL) staining was used to detect the apoptosis of myocardial cells, and JC-1 fluorescence probe to detect the changes in mitochondrial membrane potential. Western blot was employed to determine the expression levels of the autophagy-related proteins microtubule-associated proteins light chain 3Ⅱ(LC3Ⅱ), microtubule-associated proteins light chain 3Ⅰ(LC3Ⅰ), P62, Parkin and apoptosis related proteins pro caspase-3, caspase-3, B-cell lymphoma-2(Bcl-2), Bcl-2-associated X(Bax). The results showed that compared with the CON group, the IH group showed decreased fluorescence intensity of MDC staining, decreased LC3Ⅱ/LC3Ⅰ ratio, down-regulated Parkin expression, and up-regulated expression of P62. In addition, the IH group showed decreased cell survival rate, increased content of LDH and CK in the culture medium, increased number of TUNEL positive cells, and decreased pro caspase-3/caspase-3 and Bcl-2/Bax ratios and mitochondrial membrane potential. Compared with the IH group, the IH+DBD and IH+RAPA groups showed increased fluorescence intensity of MDC staining, increased LC3Ⅱ/LC3Ⅰ ratio, up-regulated Parkin expression, and down-regulated P62 expression. In addition, the two groups showed increased cell survival rate, reduced content of LDH and CK in the culture medium, decreased number of TUNEL positive cells, and increased pro caspase-3/caspase-3 and Bcl-2/Bax ratios and mitochondrial membrane potential. The IH+DBD+3-MA and IH groups showed no significant differences in the above indicators. Compared with the IH+DBD group, the IH+DBD+3-MA group showed decreased fluorescence intensity of MDC staining, decreased LC3Ⅱ/LC3Ⅰ ratio, down-regulated Parkin expression, and up-regulated P62 expression. In addition, the group had decreased cell survival rate, increased content of LDH and CK in the culture medium, increased number of TUNEL positive cells, decreased pro caspase-3/caspase-3 and Bcl-2/Bax ratios, and declined mitochon-drial membrane potential. To sum up, DBD could promote the mitophagy, inhibit the apoptosis, and alleviated the injury of H9c2 cells exposed to low oxygen.
Oxygen ; bcl-2-Associated X Protein/metabolism* ; Caspase 3/genetics* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Apoptosis ; Autophagy ; Ubiquitin-Protein Ligases ; Microtubule-Associated Proteins

Objective To explore the effect of knocking down Rho-associated coiled-coil kinase (ROCK2) gene on the cognitive function of amyloid precursor protein/presenilin-1 (APP/PS1) double transgenic mice and its mechanism. Methods APP/PS1 double transgenic mice were randomly divided into AD model group (AD group), ROCK2 gene knock-down group (shROCK2 group), ROCK2 gene knock-down control group (shNCgroup), and wild-type C57BL/6 mice of the same age served as the wild-type control (WT group). Morris water maze and Y maze were employed to test the cognitive function of mice. Neuron morphology was detected by Nissl staining. Immunofluorescence histochemical staining was used to detect the expression of phosphorylated dynamin-related protein 1 (p-Drp1) and mitochondrial fusion 1 (Mfn1). Western blot analysis was used to detect the expression ROCK2, cleaved-caspase-3 (c-caspase-3), B-cell lymphoma 2 (Bcl2), Bcl2-related protein X (BAX), p-Drp1, mitochondrial fission 1 (Fis1), optic atrophy 1 (OPA1), Mfn1 and Mfn2. Results Compared with AD group mice, the expression of ROCK2 in shROCK2 group mice was significantly reduced; the cognitive function was significantly improved with the number of neurons in the hippocampal CA3 and DG areas increasing, and nissl bodies were deeply stained; the expression of c-caspase-3 and BAX was decreased, while the expression of Bcl2 was increased; the expression of mitochondrial division related proteins p-Drp1 and Fis1 were decreased, while the expression of mitochondrial fusion-related proteins OPA1, Mfn1 and Mfn2 were increased. Conclusion Knock-down of ROCK2 gene can significantly improve the cognitive function and inhibit the apoptosis of nerve cells of APP/PS1 mice. The mechanism may be related to promoting mitochondrial fusion and inhibiting its division.
Animals ; Mice ; Alzheimer Disease/pathology* ; Amyloid beta-Peptides/metabolism* ; Amyloid beta-Protein Precursor ; Apoptosis/genetics* ; bcl-2-Associated X Protein ; Caspase 3 ; Cognition ; Disease Models, Animal ; Mice, Inbred C57BL ; Mice, Transgenic ; Mitochondrial Dynamics/genetics*

Objective To investigate the effects of miR-181b-5p on cells proliferation and apoptosis in acute myeloid leukemia (AML) by targeting paired box 9 (PAX9). Methods The relationship between expression level of PAX9 and prognosis in AML patients was analyzed by gene expression profiling interactive analysis (GEPIA) database and The Cancer Genome Atlas (TCGA) database. Kasumi-1 and AML5 cells were transfected with empty vector (Vector group) or PAX9 (PAX9 group). The proliferation activity was detected by CCK-8 assay, and cells cycle and apoptosis were detected by flow cytometry. Expressions of cyclin-dependent kinase 2 (CDK2), cyclin B1 (CCNB1), B-cell lymphoma 2 (Bcl2) and Bcl2-associated X protein (BAX) were detected by Western blot analysis. The targeted microRNA (miRNA) by PAX9 was predicted by bioinformatics analysis, and the targeted effect was verified by luciferase reporter assay. The level of PAX9 mRNA was detected by real-time quantitative PCR, and expression of PAX9 protein was detected by Western blot analysis. Kasumi-1 and AML5 cells were transfected with miR-NC (miR-NC group) or miR-181b-5p (miR-181b-5p group). The cells were further transfected with PAX9 (miR-181b-5p combined with PAX9 group) in miR-181b-5p group. The proliferation, cycle and apoptosis of cells were detected by the above methods.Results GEPIA and TCGA databases showed that the expression of PAX9 was down-regulated in AML patients, which was correlated with poor prognosis. In Kasumi-1 and AML5 cells, compared with Vector group, proliferation activity of cells, percentage of cells in S phase, and expressions of CDK2, CCNB1 and Bcl2 proteins were decreased, while percentage of cells in G0/G1 phase, apoptosis rate and the expression of BAX protein were increased in PAX9 group. It was confirmed by double luciferase reporter assay that PAX9 was the target gene of miR-181b-5p. Compared with miR-NC group, proliferation activity of cells, percentage of cells in S phase, and expressions of CDK2, CCNB1 and Bcl2 proteins were increased, while percentage of cells in G0/G1 phase, apoptosis rate and the expression of BAX protein were decreased in miR-181b-5p group. Compared with miR-181b-5p group, proliferation activity of cells, percentage of cells in S phase, and expressions of CDK2, CCNB1 and Bcl2 proteins were decreased, while percentage of cells in G0/G1 phase, apoptosis rate and the expression of BAX protein were increased in miR-181b-5p combined with PAX9 group. Conclusion The miR-181b-5p can promote the proliferation of AML cells and delay apoptosis by inhibiting PAX9.
Humans ; Apoptosis/genetics* ; bcl-2-Associated X Protein ; Cell Line, Tumor ; Cell Proliferation/genetics* ; Leukemia, Myeloid, Acute/pathology* ; Luciferases ; MicroRNAs/metabolism* ; PAX9 Transcription Factor/genetics*

OBJECTIVE: To investigate the effect of long non-coding RNA LINC01268 on apoptosis of acute myeloid leukemia (AML) cells and related mechanisms. METHODS: The expression levels of LINC01268 and miR-217 in peripheral blood samples from AML patients and AML cell lines HL-60 and KG-1 were detected by qRT-PCR. HL-60 cells were divided into pcDNA3.1-NC, pcDNA3.1-LINC01268, si-NC, si-LINC01268, miR-NC, miR-217 mimics, si-LINC01268 + inhibitor-NC and si-LINC01268+ miR-217 inhibitor groups. The mRNA expressions of LINC01268 and miR-217 were detected by qRT-PCR. The targeting relationship between LINC01268 and miR-217 was detected by dual-luciferase reporter assay. Cell viability was detected by CCK-8 assay. Cell cycle distribution and apoptosis were detected by flow cytometry. The expression of cell cycle and apoptosis-related proteins p21, Bcl-2, Bax, caspase-3 and PI3K/AKT signaling pathway-related proteins were detected by Western blot. RESULTS: The expression of LINC01268 in peripheral blood samples of AML patients and AML cell lines HL-60 and KG-1 was increased (P < 0.05), and the expression of miR-217 was decreased (P < 0.05). Compared with si-NC group and miR-NC group, the viability of HL-60 cells was decreased in si-LINC01268 group and miR-217 mimics group (P < 0.05), the proportion of cells in G₁ phase and apoptosis rate were increased (P < 0.05), the protein expression levels of p21, Bax and caspase-3 were increased (P < 0.05), while the protein expression level of Bcl-2 was decreased (P < 0.05). LINC01268 targeted and negatively regulated the expression of miR-217, and inhibiting the expression of miR-217 partially reversed the effects of LINC01268 interference on the viability, cell cycle and apoptosis of HL-60 cells. Interference with LINC01268 could inhibit the activity of PI3K/AKT signaling pathway. Inhibiting the expression of miR-217 could partially reverse the inhibition of LINC01268 interference on PI3K/AKT signaling pathway. CONCLUSION LINC01268 is highly expressed and miR-217 is lowly expressed in AML cells. LINC01268 can promote the activity of PI3K/AKT signaling pathway, increase the survival rate and inhibit the apoptosis of AML cells by targeting miR-217 expression.
Humans ; Apoptosis ; bcl-2-Associated X Protein/metabolism* ; Caspase 3 ; Cell Line, Tumor ; Cell Proliferation ; Leukemia, Myeloid, Acute/metabolism* ; MicroRNAs/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; RNA, Long Noncoding/genetics*