Redox-Based Strategy for Selectively Inducing Energy Crisis Inside Cancer Cells: An Example of Modifying Dietary Curcumin to Target Mitochondria.

Reprograming of energy metabolism is a major hallmark of cancer, but its effective intervention is still a challenging task due to metabolic heterogeneity and plasticity of cancer cells. Herein, we report a general redox-based strategy for meeting the challenge. The strategy was exemplified by a dietary curcumin analogue (MitoCur-1) that was designed to target mitochondria (MitoCur-1). By virtue of its electrophilic and mitochondrial-targeting properties, MitoCur-1 generated reactive oxygen species (ROS) more effectively and selectively in HepG2 cells than in L02 cells via the inhibition of mitochondrial antioxidative thioredoxin reductase 2 (TrxR2). The ROS generation preferentially mediated the energy crisis of HepG2 cells in a dual-inhibition fashion against both mitochondrial and glycolytic metabolisms, which could hit the metabolic plasticity of HepG2 cells. The ROS-dependent energy crisis also allowed its preferential killing of HepG2 cells (IC50 = 1.4 µM) over L02 cells (IC50 = 9.1 µM), via induction of cell-cycle arrest, apoptosis and autophagic death, and its high antitumor efficacy in vivo, in nude mice bearing HepG2 tumors (15 mg/kg). These results highlight that inhibiting mitochondrial TrxR2 to produce ROS by electrophiles is a promising redox-based strategy for the effective intervention of cancer cell energy metabolic reprograming.

[Involvement of excitatory amino acid system in astrocytes activation caused by dimethoate].

OBJECTIVE: To study the involvement of excitatory amino acid system in astrocytes activation caused by dimethoate. METHODS: Pure-cultured astrocytes were gained by three passages from primary cultured rat nerve cells, then treated with 10(-6),10(-5),10(-4) mol/L dimethoate for 48 h, 50 micromol/L and 100 micromol/L MK801, a NMDA receptor blocker, was used to intervene the effects induced by 10(-4) mol/L dimethoate. HPLC-FLD was utilized to measure the concentrations of excitatory amino acid (EAA), RT-PCR was used to detect the expression levels of NR2B, GLT-1, GLAST, GFAP and S100beta mRNA, and immunofluorescence staining method was applied to measure the expression levels of GFAP and S100beta proteins. RESULTS: The expression levels of GLAST mRNA in all exposure groups were 67.8%, 68.6% and 76.2% of control level, respectively, which were significantly lower than that of control group (P < 0.05); The concentrations of EAA significantly decreased in 10(-4) mol/L dimethoate group, as compared with control group (P < 0.01); the expression levels of GFAP mRNA in 10(-4) mol/L dimethoate group, of S100beta mRNA in 10(-5) mol/L dimethoate group, of GFAP protein in 10(-4) mol/L and 10(-5) mol/L dimethoate groups and S100beta protein in 10(-4) mol/L dimethoate group were significantly higher than those in control group (P < 0.01). The expression levels of GLT-1 and GLAST mRNA in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups increased significantly, as compared with 10(-4) mol/L dimethoate group (P < 0.01), the expression levels of NR2B mRNA in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups increased significantly, as compared with control group (P < 0.05 or P < 0.01); the concentration of Glu in 10(-4) mol/L dimethoate plus 100 micromol/L MK801 group increased significantly, as compared with 10(-4) mol/L dimethoate group (P < 0.01); the expression levels of GFAP mRNA and protein in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups decreased significantly (P < 0.01); S100beta protein expression level in 50 micromol/L MK801 intervention group was significantly higher than thatl in control group (P < 0.01). CONCLUSION: Excitatory amino acid system involved in astrocytes activation caused by dimethoate. MK801 was useful to control astrocytes gliosis.

Multifactor analysis of patients with oral sensory complaints in a case-control study.

BACKGROUND: There are an increasing number of patients with oral sensory complaints (OSCs) presenting to our dental clinic. For most dentists, it is difficult to distinguish burning mouth syndrome (BMS) from other oral mucosal diseases that may cause symptoms such as burning mouth. It is beneficial to effectively distinguish OSC patients to reduce misdiagnosis and eliminate burning symptoms as much as possible. METHODS: Patients with oral burning sensations in the oral mucosal disease clinic were collected from the Peking University Hospital of Stomatology between September 1, 2014 and December 31, 2018. After excluding oral candidiasis, anemic stomatitis, dental material allergy, and other diseases from patients with oral sensory complaints, basic conditions such as gender, age, education level, job status, hyperglycemia, hypertension, hyperlipidemia, history of brain abnormalities, history of cervical spondylitis, history of thyroid disease, history of thyroid disease and insomnia were obtained. The BMS patients were compared with the control group. The t test and Chi-square test were used for statistical analysis to compare the clinical symptoms of these diseases and explore the risk factors for BMS. RESULTS: In this case-control study, 395 patients (321 females and 74 males, mean age 55.26 ±â€Š10.51 years) with oral sensory complaints and 391 healthy controls (281 females and 110 males, mean age 47.11 ±â€Š13.10 years) were enrolled, among which, 8.4% (33/395) had oral candidiasis, 1.3% (5/395) had dental material allergy, 0.8% (3/395) had anemic stomatitis and 0.5% (2/395) had lichen planus. A total of 352 patients were eventually diagnosed with BMS. Anxiety and depression were more severe in BMS patients, as were the incidences of sleep disorders and brain abnormalities. Logistic regression analysis showed that age (odds ratio [OR] = 2.79, 95% confidence interval [CI]: 1.61-4.83, P < 0.001), total cholesterol level (OR = 2.92, 95% CI: 1.32-6.50, P = 0.009) and anxiety score (OR = 1.75, 95% CI: 1.01-2.77, P = 0.017) significantly increased the incidence of BMS. Patients with hyperglycemia (OR = 0.46, 95% CI: 0.23-0.89, P = 0.022), low body mass index (BMI: OR = 0.57, 95% CI: 0.34-0.93, P = 0.026) and low education level (OR = 3.43, 95% CI: 1.91-6.15, P < 0.001) were more likely to suffer from BMS. CONCLUSIONS: Oral candidiasis, anemic stomatitis, and dental material allergy with burning symptoms should be excluded from patients with BMS. It is recommended to conduct a questionnaire survey (including anxiety and depression), blood cell analysis, and salivary fungus culture for all patients with an oral burning sensation. It is necessary to conduct a patch test on patients with oral burning sensations and metal restorations.

[Effect of dimethoate on primary cultured rat cortical neuron].

OBJECTIVE: To investigate the effect and mechanisms of dimethoate on the primary cultured cortical neuronal cell injury. METHODS: Cortical neuronal cells were isolated and cultured in serum free medium for 6 days in vitro, and 1, 5, 10, 50 and 100 micromol/L dimethoate were added to the medium and intracellular SOD, MDA and GSH. The content of excitatory amino acid was measured after 48 hours. Flow cytometry was used to detect the neuronal cell apoptosis. RESULTS: After 48 h, the activity of SOD and the content of GSH decreased [(1.04 +/- 0.02), (0.99 +/- 0.02), (0.96 +/- 0.02), (0.91 +/- 0.02) U/mg pro] [(219.35 +/- 6.79), (205.6 +/- 6.29), (194.06 +/- 2.63), (93.68 +/- 7.56) mg/g pro], and the content of MDA increased obviously with 5, 10, 50 and 100 micromol/L dimethoate [(21.22 +/- 0.29), (24.01 +/- 0.34), (27.15 +/- 1.02), (32.91 +/- 1.39) nmol/mg pro]; The content of Asp from 10 to 100 micromol/L dose group was higher than the control group and the content of Glu from 1 to 100 micromol/L dose group was higher than the control group. The apoptosis rate had great significance between 1 to 100 micromol/L dose groups and control group. When treated with dimethoate, MDA content in neuron was positively correlated with the content of EAAs with the increase of dimethoate. The correlative coefficient was 0.937 and 0.759 respectively (P < 0.01), while it was negatively correlated with the content of GSH. The correlative coefficient was -0.868 and -0.801 respectively (P < 0.01). CONCLUSION: The oxidative damage and changes of excitatory amino acid content induced by Dimethoate contribute to the primary cultured rat cortical neuron apoptosis.

Glycemic index of cereals and tubers produced in China.

AIM: To determine the GI of some cereals and tubers produced in China in an effort to establish the database of glycemic index (GI) of Chinese food. METHODS: Food containing 50 g carbohydrate was consumed by 8-12 healthy adults after they have been fasted for 10 h and blood glucose was monitored for 2 h. Glucose was used as reference food. GI of food was calculated according to a standard method. RESULTS: GI of 9 types of sugar and 60 kinds of food were determined. CONCLUSION: Food GI is mainly determined by nature of carbohydrate and procession. Most of cereals and tubers produced in China have similar GI with their counterparts produced in other countries.