Prohibitin 1 inhibits cell proliferation and induces apoptosis via the p53-mediated mitochondrial pathway in vitro.

BACKGROUND: Prohibitin 1 (PHB1) has been identified as an antiproliferative protein that is highly conserved and ubiquitously expressed, and it participates in a variety of essential cellular functions, including apoptosis, cell cycle regulation, proliferation, and survival. Emerging evidence indicates that PHB1 may play an important role in the progression of hepatocellular carcinoma (HCC). However, the role of PHB1 in HCC is controversial. AIM: To investigate the effects of PHB1 on the proliferation and apoptosis of human HCC cells and the relevant mechanisms in vitro. METHODS: HCC patients and healthy individuals were enrolled in this study according to the inclusion and exclusion criteria; then, PHB1 levels in the sera and liver tissues of these participates were determined using ELISA, RT-PCR, and immunohistochemistry. Human HepG2 and SMMC-7721 cells were transfected with the pEGFP-PHB1 plasmid and PHB1-specific shRNA (shRNA-PHB1) for 24-72 h. Cell proliferation was analysed with an MTT assay. Cell cycle progression and apoptosis were analysed using flow cytometry (FACS). The mRNA and protein expression levels of the cell cycle-related molecules p21, Cyclin A2, Cyclin E1, and CDK2 and the cell apoptosis-related molecules cytochrome C (Cyt C), p53, Bcl-2, Bax, caspase 3, and caspase 9 were measured by real-time PCR and Western blot, respectively. RESULTS: Decreased levels of PHB1 were found in the sera and liver tissues of HCC patients compared to those of healthy individuals, and decreased PHB1 was positively correlated with low differentiation, TNM stage III-IV, and alpha-fetoprotein ≥ 400 µg/L. Overexpression of PHB1 significantly inhibited human HCC cell proliferation in a time-dependent manner. FACS revealed that the overexpression of PHB1 arrested HCC cells in the G0/G1 phase of the cell cycle and induced apoptosis. The proportion of cells in the G0/G1 phase was significantly increased and the proportion of cells in the S phase was decreased in HepG2 cells that were transfected with pEGFP-PHB1 compared with untreated control and empty vector-transfected cells. The percentage of apoptotic HepG2 cells that were transfected with pEGFP-PHB1 was 15.41% ± 1.06%, which was significantly greater than that of apoptotic control cells (3.65% ± 0.85%, P < 0.01) and empty vector-transfected cells (4.21% ± 0.52%, P < 0.01). Similar results were obtained with SMMC-7721 cells. Furthermore, the mRNA and protein expression levels of p53, p21, Bax, caspase 3, and caspase 9 were increased while the mRNA and protein expression levels of Cyclin A2, Cyclin E1, CDK2, and Bcl-2 were decreased when PHB1 was overexpressed in human HCC cells. However, when PHB1 was upregulated in human HCC cells, Cyt C expression levels were increased in the cytosol and decreased in the mitochondria, which indicated that Cyt C had been released into the cytosol. Conversely, these effects were reversed when PHB1 was knocked down. CONCLUSION: PHB1 inhibits human HCC cell viability by arresting the cell cycle and inducing cell apoptosis via activation of the p53-mediated mitochondrial pathway.

Effectiveness of enhanced recovery after surgery in the perioperative management of patients with bone surgery in China.

BACKGROUND: Enhanced recovery after surgery (ERAS) was introduced in China in 2007. Over time, the scope of ERAS has expanded from abdominal surgery to orthopedics, urology and other fields. Continuous development and research has contributed to progress of ERAS in China. In 2019, to promote the application of ERAS in bone tumor surgery, we formed the "Consensus of Experts on Perioperative Management of Accelerated Rehabilitation in Major Surgery of Bone Tumors in China". AIM: To evaluate the effect of enhanced recovery after bone tumor surgery in perioperative management in China. METHODS: One hundred and seven patients who underwent bone tumor surgery at the Second Affiliated Hospital of Xi'an Jiaotong University between May 2019 and April 2021 were randomized into a study group (53 cases) and a control group (54 cases). The study group adopted the ERAS protocol and the control group adopted conventional care. Main outcome measures included postoperative length of stay (LOS), postoperative complications, mortality, and 30-d readmission rates. Secondary outcomes included postoperative visual analog scale (VAS) score of pain, number of blood transfusions, drainage volume in 24 h after operation, patient satisfaction 30 d after discharge, VAS score at 30 d after discharge, and daily standing walking time. RESULTS: There were no significant differences in the baseline data, clinical features and surgical site between the two groups. The LOS in the study group with the ERAS protocol was 7.72 ± 3.34 d compared with 10.28 ± 4.27 d in the control group who followed conventional care. The incidence of postoperative nausea and vomiting (PONV) in the study group was 19% and 37% in the control group. The VAS scores of pain on postoperative day 1 (POD1) and POD3 in the study group were 4.79 ± 2.34 and 2.79 ± 1.53 compared with 5.28 ± 3.27 and 3.98 ± 2.27 in the control group. The drainage volume in 24 h after the operation was 124.36 ± 23.43 mL in the study group and 167.43 ± 30.87 mL in the control group. The number of blood transfusions in the study group was also lower. The patient satisfaction rate was higher in the study group than in the control group. CONCLUSION: The ERAS protocol in the perioperative period of bone tumor surgery can decrease LOS, PONV, and postoperative pain, blood transfusion and 24-h drainage, improve patient satisfaction and accelerate recovery.

[The relationship between reactive oxygen species-dependent activation of p38 MAPK and the expression of tumor necrosis factor-α in cultured cardiomyocytes].

AIM: To investigate the role of p38 mitogen-activated protein kinase(MAPK) in lipopolysaccharide (LPS)-induced tumor necrosis factor-α (TNF-α) expression in neonatal rat cardiomyocytes and to determine the relationship between reactive oxygen species (ROS) and p38 MAPK activation. METHODS: Cardiomyocytes were isolated from neonatal Sprague-Dawley rats and cultured by differential adhesion. Expression of TNF-α was determined in culture medium by ELISA. Activation of p38 MAPK was determined by Western blot analysis with phospho-specific antibody. ROS generation in cardiomyocytes was determined by peroxide specific probe 2', 7'-dichlorofluorescin diacetate (DCF-DA). RESULTS: In cardiomyocytes stimulated with LPS, the content of TNF-α in culture medium correlated with the activity of p38 MAPK in a time-dependent manner. The activation of p38 was observed after stimulation of 1 mg/L LPS for 1 h. TNF-α accumulated significantly in culture medium at 3 h after stimulation of LPS (P<0.05), which was remarkably attenuated by pretreatment with p38 MAPK specific inhibitor SB203580 (P<0.01). Furthermore, the production of ROS in cardiomyocytes stimulated with LPS was also increased at 1 h after stimulation of LPS, consistent with p38 MAPK activity. Pretreatment with antioxidants such as N-acetylcysteine and diphenyleneiodonium significantly inhibited the activation of p38 MAPK compared with LPS control (P<0.05). There was no significance in the activity of p38 MAPK among antioxidants pretreatment and non-LPS control groups. CONCLUSION: The activation of p38 MAPK plays an important role in TNF-α expression in LPS-stimulated cardiomyocytes and the increase of ROS production is prerequisite for the activation of p38 MAPK.

Simvastatin inhibits angiotensin II-induced cardiac cell hypertrophy: role of Homer 1a.

1. The scaffolding protein Homer 1a is constitutively expressed in the myocardium, although its function in cardiomyocytes remains poorly understood. The aim of the present study was to investigate Homer 1a expression in hypertrophic cardiac cells and its role in angiotensin (Ang) II-induced cardiac hypertrophy. 2. After serum starvation for 24 h, cells were treated with 1 micromol/L simvastatin, 100 nmol/L angiotensin (Ang) II or their combination added to Dulbecco's modified Eagle's medium containing 0.5% serum. For combination treatment with AngII plus simvastatin, cells were exposed to simvastatin 12 h before the addition of AngII to the medium and cells were then incubated in the presence of both drugs for a further 24 h. Western blotting was used to determine Homer 1a protein expression. Hypertrophy was evaluated by determining the protein content per cell. 3. Homer 1a protein levels were upregulated following AngII-induced hypertrophy in H9C2 cells and neonatal rat cardiomyocytes, and these increases were augmented by simvastatin pretreatment. Concomitantly, simvastatin pretreatment inhibited extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and AngII-induced hypertrophy. 4. The inhibitory effects of simvastatin against AngII-induced hypertrophy were attenuated by Homer 1a silencing, suggesting that simvastatin suppresses cardiac hypertrophy in a Homer 1a-dependent manner. Furthermore, AngII-induced hypertrophy and ERK1/2 phosphorylation in neonatal rat cardiomyocytes were significantly inhibited following the overexpression of Homer 1a using an adenovirus. 5. These results suggest a possible role for Homer 1a in inhibiting cardiac hypertrophy perhaps in part through inhibition of ERK1/2 activation.

Heated lipiodol as an embolization agent for transhepatic arterial embolization in VX2 rabbit liver cancer model.

PURPOSE: To evaluate the therapeutic effect of heated (60 degrees C) lipiodol via hepatic artery administration in a rabbit model of VX2 liver cancer. MATERIALS AND METHODS: Thirty male New Zealand white rabbits were randomly divided into three groups with 10 rabbits assigned to each group. VX2 carcinoma cells were surgically implanted into the left hepatic lobe. The tumors were allowed to grow for 2 weeks, and studies were performed until the diameter of the tumors detected by ultrasonograph reached 2-3cm. Under anesthesia, trans-catheter hepatic arterial embolization was performed and doxorubicin-lipiodol (37 degrees C) (1mL), lipiodol (60 degrees C) (1mL) or control (physiological saline (37 degrees C) (1mL)) solution was injected into the hepatic arteries of animals in the three groups. One week later, the volume of the tumor was measured by ultrasonograph again. The serum of all rabbits was collected before injection and at 4 and 7 days after injection, and the level of aspartate aminotransferase (AST) was checked. The survival period of the three groups of rabbits after treatment was also recorded. During the last course of their disease, the rabbits were given analgesics to relieve suffering. RESULTS: The tumor growth rate in the lipiodol (60 degrees C) group (0.92+/-0.21, tumor volume from 1811+/-435 to 1670+/-564mm(3)) was significantly lower than that in the control group (3.48+/-1.17, tumor volume from 1808+/-756 to 5747+/-1341mm(3)) (P<0.05) and in the doxorubicin-lipiodol (37 degrees C) group (1.69+/-0.26, tumor volume from 1881+/-641 to 2428+/-752mm(3)) (P<0.05). Consequently, the survival period of the animals in the lipiodol (60 degrees C) group (41.0+/-3.0 days) was significantly greater than that in the doxorubicin-lipiodol (37 degrees C) group (38.0+/-2.5 days) (P<0.05). On the other hand, there was no statistically significant difference in serum AST levels between the lipiodol (60 degrees C) group (148.2+/-11.3UL(-1)) and the doxorubicin-lipiodol (37 degrees C) group (139.7+/-12.3UL(-1)) (P>0.05). However, the serum AST level in the lipiodol (60 degrees C) group was significantly higher at 4 days after injection (P<0.05) than in the control group (68.6+/-6.6UL(-1)). CONCLUSIONS: Treatment with lipiodol (60 degrees C) resulted in an effect on serum AST levels similar to that caused by treatment with doxorubicin-lipiodol (37 degrees C). Thus, lipiodol (60 degrees C) treatment could greatly prolong the survival period of rabbits with VX2 cancer by inhibiting tumor growth.

Using embryonic stem cells to form a biological pacemaker via tissue engineering technology.

Biological pacemakers can be achieved by various gene-based and cell-based approaches. Embryonic stem cells (ESCs)-derived pacemaker cells might be the most promising way to form biological pacemakers, but there are challenges as to how to control the differentiation of ESCs and to overcome the neoplasia, proarrhythmia, or immunogenicity resulting from the use of ESCs. As a potential approach to solve these difficult problems, tissue-engineering techniques may provide a precise control on the different cell components of multicellular aggregates and the forming of a construct with-defined architectures and functional properties. The combined interactions between ESC-derived pacemaker cells, supporting cells, and matrices may completely reproduce pacemaker properties and result in a steady functional unit to induce rhythmic electrical and contractile activities. As ESCs have a high capability for self-renewal, proliferation, and potential differentiation, we hypothesize that ESCs can be used as a source of pacemaker cells for tissue-engineering applications and the ambitious goal of biological cardiac pacemakers may ultimately be achieved with ESCs via tissue-engineering technology.