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Pheochromocytoma is a tumor of the adrenal medulla for which surgical resection is the only therapy. Though the Notch1 signaling pathway has been suggested as a target for pheochromocytoma treatment, the effect of Notch1 intracellular domain (NICD) on pheochromocytoma cell growth remains unknown. In the present study, the effect of NICD on pheochromocytoma cell growth was examined, by use of a tetracycline‑inducible system for NICD overexpression in the PC12 pheochromocytoma cell line. Flow cytometry was used to determine the effect of NICD on cell cycle phase distribution and apoptosis in PC12 cells. Protein expression levels of microtubule associated protein 1 light chain 3 B (LC3B), Beclin 1, autophagy‑related (ATG) 5 and ATG7 were examined using western blot analysis. Untreated PC12 cells lack NICD expression, while treatment with doxycycline resulted in a significant NICD overexpression. NICD overexpression promoted cell apoptosis and suppressed cell proliferation via regulating S‑phase arrest. In addition, NICD overexpression stimulated the expression of autophagy‑related proteins LC3B, Beclin 1, ATG5 and ATG7. In conclusion, NICD promoted cell apoptosis, suppressed cell proliferation, and stimulated autophagy‑related protein expression in PC12 cells. The present data indicate that overexpression of NICD may be a promising potential therapy for pheochromocytoma.

Hepatocyte apoptosis and energy metabolism in mitochondria have an important role in the mechanism of acute liver failure (ALF). However, data on the association between apoptosis and the energy metabolism of hepatocytes are lacking. The current study assessed the activity of several key enzymes in mitochondria during ALF, including citrate synthase (CS), carnitine palmitoyltransferase‑1 (CPT‑1) and cytochrome c oxidase (COX), which are involved in hepatocyte energy metabolism. A total of 40 male Sprague‑Dawley rats were divided into five groups and administered D‑galactosamine and lipopolysaccharide to induce ALF. Hepatic pathology and terminal deoxynucleotidyl transferase‑mediated dUTP nick end labeling examinations indicated that hepatocyte apoptosis was observed at 4 h and increased 8 h after ALF. Hepatocyte necrosis appeared at 12 h and was significantly higher at 24 h with inflammatory cell invasion. The results measured by electron microscopy indicated that ultrastructural changes in mitochondria began at 4 h and the mitochondrial outer membrane was completely disrupted at 24 h resulting in mitochondrial collapse. The expression of CS, CPT‑1 and COX was measured and analyzed using assay kits. The activity and protein expression of CS, CPT‑1 and COX began to increase at 4 h, reached a peak at 8 h and decreased at 12 h during ALF. The activities of CS, CPT‑1 and COX were enhanced during hepatocyte apoptosis suggesting that these enzymes are involved in the initiation and development of ALF. Therefore, these results demonstrated that energy metabolism is important in hepatocyte apoptosis during ALF and hepatocyte apoptosis is an active and energy‑consuming procedure. The current study on how hepatocyte energy metabolism affects the transmission of death signals may provide a basis for the early diagnosis and development of an improved therapeutic strategy for ALF.

Our previous study found that glucosylceramide, a type of sphingolipids, was associated with liver inflammation and fibrosis. Glucosylceramide is generated by glucosylceramide synthase (GCS), which is encoded by the UDP-glucose ceramide glucosyltransferase (UGCG) gene. GCS is a key enzyme to regulate the physiological activity of cells. However, the role of GCS in hepatic cells remains unclear. The aim of the present study was to explore the mechanism of GCS in the proliferation and apoptosis of liver cells. Following the interference of expression of GCS in vitro by UGCG small interfering (si)RNA, the MTT method was performed to detect the proliferation of HL-7702 hepatocytes, and ELISA was used to determine the concentration of tumor necrosis factor (TNF) α and cytochrome c in the supernatant of culture system. Fluorescence microscopy was used to observe the apoptosis of liver cells stained by Annexin V-fluorescein isothiocyanate/propidium iodide. Reverse transcription-quantitative polymerase chain reaction was used to detect the gene expression apoptosis regulator Bcl-2 (Bcl-2), apoptosis regulator Bax (Bax) and caspase-3. Western blot analysis was used to detect the expression of caspase-3 protein in the liver cells. Following treatment with UGCG siRNA for 24 h, the proliferation of HL-7702 hepatocytes was significantly inhibited when compared with the transfection reagent group. Furthermore, the early and advanced apoptosis of liver cells showed an increasing trend. Additionally, concentrations of TNF α and cytochrome c showed no significant difference between the UGCG siRNA and transfection reagent groups. Compared with the transfection reagent group, Bcl-2 mRNA expression decreased, and Bax and caspase-3 mRNA expression increased in the UGCG siRNA transfection group. The protein expression level of caspase-3 showed increased in hepatocytes following the treatment with UGCG siRNA. In conclusion, the metabolic changes of sphingolipids caused by the lack of GCS may be involved in the proliferation and apoptosis of liver cells through the Bcl-2/Bax signaling pathway.

The expression of BECLIN1 is significantly reduced in non‑small cell lung cancer (NSCLC) compared with non‑cancerous tissue. However, the role of BECLIN1 in lung cancer is unclear. Using the RNA interference (RNAi) technique the present study investigated the effect of the knockdown of BECLIN1 on the cell growth and proliferation of the A549 human lung cancer cell line. The target site for the RNAi technique was designed and the lentivirus vector for the small interfering (si)RNA expression was constructed according to the encoding sequence of the mRNA for BECLIN1. The A549 cells were transfected with the siRNA virus against BECLIN1. BECLIN1 expression was detected by reverse transcription (RT)‑PCR and western blot analysis. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method was applied to detect cell growth. Flow cytometry was used to determine cell apoptosis. The activity of caspase‑3 and caspase‑9 was also detected in the A549 cells with BECLIN1 knockdown. The results showed that siRNA virus transfection significantly decreased the mRNA and protein expression of BECLIN1 in the transfected A549 cells. The knockdown of BECLIN1 promoted cell growth and decreased apoptosis. Caspase‑3 and ‑9 activity in the A549 cells with BECLIN1 knockdown was significantly reduced. In conclusion, the siRNA expression vector effectively inhibited the expression of BECLIN1 in the A549 human lung cancer cell line and promote the growth and proliferation of the A549 cells.

The plasma profile of sphingolipids in hepatic fibrosis patients with chronic hepatitis C (CHC) is rarely considered at present. The association between plasma sphingolipids and severe fibrosis in CHC remains an obscure area of research. The aim of the present study was to assess the plasma profile of sphingolipids and to examine the association between plasma sphingolipids and severe fibrosis in CHC, in order to identify potential novel markers of severe fibrosis in CHC. A cohort of 120 treatment-naive patients with CHC were included in the present study. Liver biopsies were performed and routine serological indicators were measured. Plasma sphingolipids were detected using high performance liquid chromatography tandem mass spectrometry. A total of 44 plasma sphingolipids were detected. Plasma hexosylceramide (HexCer; d18:1/12:0), HexCer (d18:1/16:0) and HexCer (d18:1/22:0) were shown to be significantly different in patients with CHC between those with and without severe fibrosis (Metavir F ≥ 3; P < 0.05). HexCer (d18:1/12:0) was observed to be closely associated with severe fibrosis in CHC [odds ratio (OR)=1.03] following adjustment for confounding variables in a multivariate analysis. HexCer (d18:1/12:0) had diagnostic value for severe fibrosis in CHC [area under the curve (AUC)=0.69]. In patients with CHC who had developed significant fibrosis (Metavir F ≥ 2), HexCer (d18:1/12:0) remained closely associated with severe fibrosis (OR=1.08) in this subgroup. In addition, HexCer (d18:1/12:0) had sufficient diagnostic ability (AUC=0.73) to distinguish severe fibrosis in patients with CHC with significant fibrosis. In conclusion, the present study indicated that plasma HexCer (d18:1/12:0) exhibits a close correlation with severe hepatic fibrosis in CHC, particularly in patients who have significant fibrosis. Additionally, HexCer (d18:1/12:0) may be a potential marker of severe hepatic fibrosis in CHC.

The purpose of the present study was to investigate the role of autophagy on rat bone marrow mesenchymal stem cell (BMSC) proliferation, apoptosis and differentiation into neurons. After treatment with rapamycin, 3-methyladenine (3-MA) or chloroquine, the cell cycle, apoptosis, expression of neuron-specific enolase (NSE) and the mean fluorescence intensity (MFI) of Notch1 in BMSCs were examined by flow cytometry. The expression of microtubule-associated protein 2 (MAP2), Notch1 and Hes1 was investigated by western blot analysis. The results showed that after induction of autophagy using rapamycin, the proliferation of BMSCs was inhibited. Furthermore, the S-phase population was significantly decreased compared to that in the control group (P