BACKGROUND:Compared with the conventional composite resin, the 3M Z350 nano-resin has good wear
resistance, physical mechanical properties, and polishing, and exerts a lower irritation to the dental pulp. Besides fil ing materials, a reliable tooth-prosthesis bonding interface is necessary for resin bonded repairs.
OBJECTIVE:To compare the clinical effects of self-etch bonding Adper Easy One and total-etch bonding Single Bond 2 on nano-resin bonding restoration of the anterior teeth.
METHODS:120 anterior teeth with vital pulp, which had defects at the incisal ends and were to be restored with nano resins, were divided into two groups randomly. Two kinds of adhesives, self-etch adhesive and total-etch adhesive, combined with nano-resin were used to restore the teeth. The patients were re-examined immediately, 6 months, 1 year and 2 years after the treatment. The fil ings, teeth and pulps of patients were examined,
including whether the prosthesis and tooth color were coordinated, whether the gap between the prosthesis and the teeth were sealed, whether the surface of the prosthesis was intact with no loose, whether the prosthesis and teeth had no staining and secondary caries, whether the condition of the tooth pulp had hot or cold
stimulation-induced pain.
RESULTS AND CONCLUSION:No significant difference in the fil ing effects was found between the two groups when the patients were re-examined immediately, 6 months and 1 year after the treatment (P>0.05). The pulp
lesions of the self-etching group were fewer than those of the total-etch group 2 years after the treatment (P<0.05). Self-etching group had 1, 6, 0, 2 cases and total-etch group had 0, 2, 1, 2 cases in uncoordinated color, edge seal,
incomplete restoration and secondary caries, respectively. No statistical y significant differences were found in these four aspects between the two groups (P>0.05). The 2-year fol ow up showed a low incidence of pulp lesions and satisfactory clinical performance after 3M Z350 nano-resin working with self-etching bonding system in the nano-resin fil ing of
anterior teeth with vital pulp.

Objective To explore the plasma level of retinol binding protein 4 (RBP4) in patients with es-sential hypertension (EH) of Xinjiang Kazakans and the relations between plasma RBP4 level and blood pressure, blood lipids,blood glucose, insulin, and HOMA-IR. Methods 81 Kazakans cases who were investigated between August and November of 2008 were selected as subjects. They were divided into EH group(n=41)and control group (n=40). Blood pressure was measured. Fasting venous blood was drawn to detect the plasma RBP4, fasting insulin (FINS), fasting plasma glucose(FPG), total cholesterol(TC), triglyceride(TG), high density lipoprotein cholesterol (HDL-C)、low density lipoprotein cholesterol (LDL-C), apoprotein-A1 (APO-A1) and apoprotein-B (APO-B), and concentration in EH group was significantly higher than that in control group[ (32.74±9.93) mg/L vs (21.92± pressure (DBP),FPG,and HOMA-IR in EH group(r,=0.618,0.775,0.565,0.317,0.369,P<0.01 or P< showed that SBP was independent factor to affect the RBP4 level in EH group(Standardized Coefficients is 0.591, t=5. 695, P=0.000). Conclusion The plasma RBP4 concentration is increased in patients with EH of Kazakans, and is positively correlated with SBP,DBP,FPG,HOMA-IR in EH group. RBP4 may involve in the development of EH by promoting insulin resistance.

BACKGROUND:Microleakage between restoration, tooth structure and bonding agent can cause the entry of bacteria and liquid in the mouth into the gap, thereby damaging the bonding interface between the restoration and tooth tissues, and leading to bond failure. Microleakage detection can directly show whether the closure of the root canal of post and core system is good or bad. The severity of microleakage directly affects the restorative effects of post and core. OBJECTIVE: To evaluate the effects of different root canal cleaning methods on the microleakage between the fiber post and root canal dentin. METHODS: Thirty fresh non-caries premolar posts with free root canalin vitro were randomly divided into five groups, and the root canal wal was respectively washed with saline, 5.25% sodium hypochlorite solution+17% ethylenediamine tetra-acetic acid (EDTA)+saline, 3% hydrogen peroxide solution+5.25% sodium hypochlorite+ saline, 3% hydrogen peroxide solution+2% chlorhexidine solution+saline, and 2% chlorhexidine solution+17% EDTA+saline in different groups. Super-bond C&B adhesive agent was used for bonding fiber post, and the microleakage of each sample was observed under stereomicroscope. RESULTS AND CONCLUSION: The severity of microleakage in the al groups was ranged as folows: saline group > 3% hydrogen peroxide solution+5.25% sodium hypochlorite+saline group > 5.25% sodium hypochlorite solution+17% EDTA+saline and 3% hydrogen peroxide solution+2% chlorhexidine solution+saline groups > 2% chlorhexidine solution+17% EDTA+saline group.

Objective:To evaluate the effect of berberine on the volume and weight of, cell proliferation and apoptosis in transplanted cutaneous squamous cell carcinoma (cSCC) in nude mice inoculated with A431 cells, and to explore the possible mechanism underlying the inhibitory effect of berberine on cSCC.Methods:A431 cells were cultured, and A431 cell suspension was subcutaneously injected into the back of 20 nude mice to establish a nude mouse model of transplanted cSCC. On day 15 after inoculation, these tumor-bearing mice were randomly and equally divided into 4 groups: low-, medium- and high-dose berberine groups intraperitoneally injected with 10, 20 and 25 mg/kg berberine solution respectively, and control group intraperitoneally injected with sodium chloride physiological solution. The treatment was performed once a day for 35 consecutive days. The tumor volume was measured before, and on days 7, 14, 21, 28 and 35 after the start of treatment. After the end of the experiment, the nude mice were sacrificed, and the tumors were removed and weighed to calculate the tumor growth inhibition rate. Histopathological examination was performed in these transplanted tumors, immunohistochemical study was conducted to determine the expression of Ki67, TUNNEL staining was conducted to determine the number of apoptotic cells in the transplanted tumor tissues, fluorescence-based quantitative PCR and Western blot analysis were employed to determine the mRNA and protein expression of apoptosis-related proteins Bax, Bcl-2, caspase-3 and Ezrin respectively. One-way analysis of variance was used for comparisons among multiple groups, and Dunnett- t test for comparisons of each berberine group with the control group. Results:Along with the increase in the dose of berberine and treatment duration, the tumor growth curve gradually became flat, the tumor growth was inhibited to different degrees in the berberine groups, and the high-dose berberine showed the strongest inhibitory effect on the tumor growth. The tumor growth inhibition rate was 31.05%, 66.68%, 76.49% in the low-, medium-, and high-dose berberine groups respectively, and the tumor weight was significantly lower in the 3 berberine groups than in the control group ( t = 4.07, 6.33, 7.26, respectively, all P < 0.01) . Along with the increase in the dose of berberine, histopathological examination of the transplanted tumors showed that the extent and area of tumor cell necrosis increased, while immunohistochemical study showed that the number of Ki67-positive cells gradually decreased. Moreover, the number of Ki67-positive cells was significantly lower in the low-, medium- and high-dose berberine groups than in the control group (all P < 0.01) , but the number of apoptotic cells was significantly higher in the berberine groups than in the control group ( P < 0.05 or < 0.01) . The mRNA and protein expression of Bax, Bcl-2, caspase-3 and Ezrin significantly differed among the 4 groups (all P < 0.01) . In addition, the mRNA expression of Bcl-2 was significantly lower in the low-, medium- and high-dose berberine groups than in the control group (all P < 0.01) , and the protein expression of Bcl-2 was significantly lower in the medium- and high-dose berberine groups than in the control group (both P < 0.01) ; Bax mRNA expression in the high-dose berberine group and caspase-3 mRNA expression in the medium- and high-dose berberine groups were significantly higher than the corresponding mRNAs in the control group respectively ( P < 0.05 or < 0.01) , and the protein expression of Bax and caspase-3 was significantly higher in the low-, medium- and high-dose berberine groups than in the control group (all P < 0.01) ; Ezrin mRNA expression was significantly higher in the high-dose berberine group than in the control group ( P < 0.01) , but its protein expression was significantly lower in the low-, medium-, and high-dose berberine groups than in the control group (all P < 0.01) . Conclusion:Berberine can inhibit the proliferation of A431 cells and promote their apoptosis in the transplanted cSCC of the nude mice, and then suppress the growth of transplanted cSCC in the nude mice to a certain extent, which may be related to the upregulation of Bax and caspase-3 and downregulation of Bcl-2 and Ezrin.

Objective: To explore the effects of change of activity of vacuolar adenosine triphosphatase (V-ATPase) of myocardial lysosome on myocardial damage in rats after severe burn and its mechanism. Methods: The myocardial lysosomes were extracted from the hearts of 12 SD rats with ultra-high speed gradient density centrifugation, then Western blotting and transmission electron microscope observation were conducted for identification. One hundred and twenty rats were divided into pure burn group, ATP group, normal control group, and bafilomycin group according to the random number table, with 30 rats in each group. Rats in pure burn group and ATP group were inflicted with 40% TBSA full-thickness scald on the back. Immediately after injury, rats in pure burn group were intraperitoneally injected with lactated Ringer′s solution in 4 mL·%TBSA^-1·kg^-1, and rats in ATP group were intraperitoneally injected with ATP in 0.4 mg/kg at 12 h before burn, immediately after burn, and 12 h after burn. Rats in normal control group did not receive any treatment, and rats in bafilomycin group were intraperitoneally injected with bafilomycin A1 in 0.3 mg/kg at the same time points as those of ATP group. At 24 h after burn, 30 rats from each group were collected for determining activity of V-ATPase of myocardial lysosome with coupled-enzyme assay and the expression of myocardium autophagy-related proteins microtubule-associated protein 1 light chain 3 (LC3) and P62 by Western blotting. Left ventricular arterial blood was collected to detect the content of 5 items of myocardial enzyme spectrum and cardiac troponin T (cTnT). Data were processed with one-way analysis of variance and t test. Results: (1) After identification, both the expression level of lysosome-related membrane protein 1 and purity of lysosome in the sample were high, and the structure of lysosome was intact. (2) At 24 h after burn, the activity values of V-ATPase of myocardial lysosome in rats of pure burn group, ATP group, normal control group, and bafilomycin group were (2.03±0.67), (3.01±0.58), (4.29±0.26), and (1.83±0.52) μmol·mg^-1·h^-1, respectively. The activity value of V-ATPase of myocardial lysosome in rats of pure burn group was significantly lower than the values in ATP group and normal control group (with t values respectively 3.14 and 8.87, P values below 0.01). The activity values of V-ATPase of rats in normal control group were significantly higher than those in bafilomycin group (t=11.87, P<0.01). At 24 h after burn, the expressions of myocardial LC3 and P62 in pure burn group were significantly higher than those in ATP group and normal control group (with t values from 3.73 to 5.88, P values below 0.01). The expressions of myocardial LC3 and P62 in normal control group were significantly lower than those in bafilomycin group (with t values respectively 2.64 and 3.07, P<0.05 or P<0.01). At 24 h after burn, the content of 5 items of myocardial enzyme spectrum and cTnT in pure burn group was significantly higher than that in ATP group and normal control group (with t values from 3.24 to 16.72, P values below 0.01). The content of 5 items of myocardial enzyme spectrum and cTnT in normal control group was significantly lower than that in bafilomycin group (with t values from 2.39 to 10. 70, P values below 0.01). Conclusions The activity of V-ATPase of myocardial lysosome decreased in rats after severe burn, which can result in myocardial damage by inhibiting myocardial autophagy flux.

Objective: To investigate the role of hexokinase Ⅱ in the changes of autophagic flow in cardiomyocytes of mice with ischemia-hypoxia in vitro. Methods: The hearts of totally six male and female C57BL/6 mice aged from 1 to 2 days were isolated to culture primary cardiomyocytes which were used for the following experiments. (1) The cells were divided into 6 groups according to the random number table (the same grouping method below), i. e., normal control 3, 6, and 9 h groups and ischemia-hypoxia 3, 6, and 9 h groups, with 4 wells in each group. After being regularly cultured for 48 h with Dulbecco′s modified Eagle medium/nutrient mixture F12 (DMEM/F12) medium (the same regular culture condition below), the cells in normal control 3, 6, and 9 h groups were cultured with replaced fresh DMEM/F12 medium for 3, 6, and 9 h, respectively, and the cells in ischemia-hypoxia 3, 6, and 9 h groups were cultured with replaced sugar-free serum-free medium in the low-oxygen incubator with a volume fraction of 1% oxygen and a volume fraction of 5% carbon dioxide at 37 ℃ (the same hypoxic culture condition below) for 3, 6, and 9 h, respectively. Cell viability was measured by the cell counting kit 8 (CCK-8) method. (2) The cells were grouped and treated the same as those in experiment (1), with 1 well in each group. Western blotting was used to detect the protein expressions of microtubule-associated protein 1 light chain 3 Ⅰ (LC3Ⅰ), LC3Ⅱ, p62, and hexokinase Ⅱ. (3) The cells were divided into normal control group, simple ischemia-hypoxia 9 h group, and ischemia-hypoxia 9 h+ 2-deoxyglucose (2-DG) group, with 4 wells in each group. After a regular culture for 48 h, the cells in normal control group were cultured with replaced fresh DMEM/F12 medium for 9 h; the cells in simple ischemia-hypoxia 9 h group were replaced with sugar-free serum-free medium, and the cells in ischemia-hypoxia 9 h+ 2-DG group were replaced with sugar-free serum-free medium in which 2-DG was dissolved in a concentration of 10 mmol/L (20 μmol), and then they were cultured with hypoxia for 9 h. Cell viability was measured by CCK-8 method. (4) The cells were grouped and treated the same as those in experiment (3), with 1 well in each group. Western blotting was used to detect the protein expressions of LC3Ⅰ, LC3Ⅱ, and p62. (5) The cells were grouped and treated the same as those in experiment (3), with 2 wells in each group. Transmission electron microscope was used to observe autophagosomes/autolysosomes in cardiomyocytes. (6) The cells were divided into normal control group, simple ischemia-hypoxia 9 h group, ischemia-hypoxia 9 h+ hexosinase Ⅱ small interfering RNA1 (HK-ⅡsiRNA1) group, and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group, with 4 wells in each group. The cells in normal control group and simple ischemia-hypoxia 9 h group were regularly cultured for 48 h, and the cells in ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were respectively transfected with 200 nmol/L HK-ⅡsiRNA1 and HK-ⅡsiRNA2 and then also cultured for 48 h. The cells in normal control group were cultured with replaced fresh DMEM/F12 medium for 9 h, and the cells in simple ischemia-hypoxia 9 h group, ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group, and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were cultured with replaced sugar-free serum-free medium and hypoxia for 9 h. Cell viability was measured by CCK-8 method. (7) The cells were grouped and treated the same as those in experiment (6), with 1 well in each group. Western blotting was used to detect the protein expressions of LC3Ⅰ, LC3Ⅱ, p62, and hexokinase Ⅱ. Except for experiment (5), each experiment was repeated 3 times. Data were processed with one-way analysis of variance and lest significant difference t test, and Bonferroni correction. Results: (1) The viabilities of cardiomyocytes in ischemia-hypoxia 3, 6, and 9 h groups were 0.450±0.022, 0.385±0.010, and 0.335±0.015, respectively, which were significantly lower than 0.662±0.026, 0.656±0.028, and 0.661±0.021 of the corresponding normal control 3, 6, and 9 h groups, respectively (t=6.21, 9.12, 12.48, P<0.01). (2) Compared with those of corresponding normal control 3, 6, and 9 h groups, the LC3Ⅱ/Ⅰ ratio and protein expressions of p62 and hexokinase Ⅱ in cardiomyocytes of ischemia-hypoxia 3, 6, and 9 h groups were significantly increased (t_{3 h}=16.15, 10.99, 5.30, t_{6 h}=6.79, 10.42, 9.42, t_{9 h}=15.76, 16.51, 7.20, P<0.05 or P<0.01). (3) The viability of cardiomyocytes in simple ischemia-hypoxia 9 h group was 0.353±0.022, which was significantly lower than 0.673±0.027 of normal control group (t=9.29, P<0.01). The viability of cardiomyocytes in ischemia-hypoxia 9 h+ 2-DG group was 0.472±0.025, which was significantly higher than that of simple ischemia-hypoxia 9 h group (t=3.60, P<0.05). (4) Compared with those of normal control group, the LC3Ⅱ/Ⅰ ratio and protein expression of p62 in cardiomyocytes of simple ischemia-hypoxia 9 h group were significantly increased (t=9.45, 8.40, P<0.01). Compared with those of simple ischemia-hypoxia 9 h group, the LC3Ⅱ/Ⅰratio and protein expression of p62 in cardiomyocytes of ischemia-hypoxia 9 h+ 2-DG group were significantly decreased (t=4.39, 4.74, P<0.05). (5) In cardiomyocytes of normal control group, only single autophagosome/autolysosome with bilayer membrane structure was observed. Compared with that of normal control group, the number of autophagosome/autolysosome with bilayer membrane structure in cardiomyocytes of simple ischemia-hypoxia 9 h group was increased significantly. Compared with that of simple ischemia-hypoxia 9 h group, the number of autophagosome/autolysosome with bilayer membrane structure in cardiomyocytes of ischemia-hypoxia 9 h+ 2-DG group was significantly decreased. (6) The viability of cardiomyocytes in simple ischemia-hypoxia 9 h group was 0.358±0.023, which was significantly lower than 0.673±0.026 in normal control group (t=9.12, P<0.01). The viabilities of cardiomyocytes in ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were 0.487±0.027 and 0.493±0.022, respectively, which were significantly higher than the viability in simple ischemia-hypoxia 9 h group (t=3.63, 4.28, P<0.05). (7) Compared with those of normal control group, the LC3Ⅱ/Ⅰratio and protein expressions of p62 and hexokinase Ⅱ in cardiomyocytes of simple ischemia-hypoxia 9 h group were significantly increased (t=6.08, 6.31, 4.83, P<0.05 or P<0.01). Compared with those of simple ischemia-hypoxia 9 h group, the LC3Ⅱ/Ⅰ ratio and protein expressions of p62 and hexokinase Ⅱ in cardiomyocytes of ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were significantly decreased (t=5.10, 7.76, 15.33, 4.17, 8.42, 12.11, P<0.05 or P<0.01). Conclusions Ischemia-hypoxia upregulates the expression level of hexokinase Ⅱ protein in mouse cardiomyocytes cultured in vitro, which decreases the viability of cardiomyocytes by impairing autophagic flow. To inhibit the activity of hexokinase Ⅱ or its expression can alleviate the ischemia-hypoxia damage of cardiomyocytes.

Objective: To investigate the effect of human antigen R on lysosomal acidification during autophagy in mouse cardiomyocytes cultured in vitro. Methods: The hearts of 20 C57BL/6 mice aged 1-2 days no matter male or female were isolated to culture primary cardiomyocytes which were used in the following experiments. (1) The cells were divided into 5 groups according to the random number table (the same grouping method below), i. e., normal control group and sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups. The cells in normal control group were routinely cultured for 54.0 h with Dulbecco′s modified Eagle medium/nutrient mixture F12 (DMEM/F12) medium (the same regular culture condition below), and the cells in sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups were firstly regularly cultured for 53.5, 53.0, 51.0, 48.0 h and then cultured with replaced sugar-free serum-free medium for 0.5, 1.0, 3.0, and 6.0 h, respectively. The protein expressions of microtubule-associated protein 1 light chain 3 Ⅱ (LC3Ⅱ), autophagy-related protein 5, and adenosine triphosphatase V1 region E1 subunit (ATP6V1E1) were detected by Western blotting. (2) The cells were divided into normal control group and sugar-free serum-free 3.0 h group. The cells in corresponding groups were treated the same as those in experiment (1), and the cell lysosomal acidification level was observed and detected under a laser scanning confocal microscope. (3) Two batches of cells were grouped and treated the same as those in experiment (1). The protein expression of human antigen R in the whole protein of cells of one batch and its protein expression in the cytoplasm and nucleus protein of cells of the other batch were detected by Western blotting. (4) The cells were divided into normal control group, simple control small interfering RNA (siRNA) group, simple human antigen R-siRNA1 (HuR-siRNA1) group, simple HuR-siRNA2 group, sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, sugar-free serum-free+ HuR-siRNA1 group, and sugar-free serum-free+ HuR-siRNA2 group. After 48 hours of regular culture, the cells in simple control siRNA group and sugar-free serum-free+ control siRNA group were transfected with negative control siRNA for 6 h, the cells in simple HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA1 group were transfected with HuR-siRNA1 for 6 h, and the cells in simple HuR-siRNA2 group and sugar-free serum-free+ HuR-siRNA2 group were transfected with HuR-siRNA2 for 6 h. Hereafter, the cells in these 8 groups were continuously cultured for 48 h with regular conditon, and then the cells in normal control group and each simple siRNA-treated group were replaced with DMEM/F12 medium, the cells in the other groups were replaced with sugar-free serum-free medium, and they were cultured for 3 h. The protein expression of human antigen R in the whole protein of cells was detected by Western blotting. (5) Two batches of cells were divided into sugar-free serum-free+ control siRNA group and sugar-free serum-free+ HuR-siRNA1 group, and the cells in corresponding groups were treated the same as those in experiment (4). The distribution and expression of human antigen R in the cells of one batch were observed and detected by immunofluorescence method, and the lysosomal acidification level in the cells of the other batch was observed and detected under a laser scanning confocal microscope. (6) Three batches of cells were divided into sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, sugar-free serum-free+ HuR-siRNA1 group, and sugar-free serum-free+ HuR-siRNA2 group, and the cells in corresponding groups were treated the same as those in experiment (4). The protein expressions of cathepsin D in the whole protein of cells of one batch, human antigen R in the cytoplasm protein of cells of one batch, and ATP6V1E1 in the whole protein of cells of the other batch were detected by Western blotting. (7) The cells were divided into normal control group, sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, and sugar-free serum-free+ HuR-siRNA1 group, and the cells in corresponding groups were treated the same as those in experiment (4). The mRNA expression of ATP6V1E1 in cells was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. The sample number of each experiment was 3. Data were processed with independent data t test, one-way analysis of variance, least significant difference t test, and Bonferroni correction. Results: (1) Compared with those of normal control group, the protein expressions of LC3Ⅱ and ATP6V1E1 in the whole protein of cells of sugar-free serum-free 1.0, 3.0, and 6.0 h groups were significantly increased (t=12.16, 4.05, 4.82, 11.64, 3.29, 8.37, P<0.05 or P<0.01). Compared with that of normal control group, the protein expression of autophagy-related protein 5 in the whole protein of cells of sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups was significantly increased (t=6.88, 10.56, 5.76, 9.91, P<0.05 or P<0.01). (2) Compared with 1.03±0.08 of normal control group, the lysosomal acidification level in the cells of sugar-free serum-free 3.0 group (2.92±0.30) was significantly increased (t=6.01, P<0.01). (3) There was no statistically significant difference in the overall comparison of protein expression of human antigen R in the whole protein of cells among the 5 groups (F=1.09, P>0.05). Compared with that of normal control group, the protein expression of human antigen R in the cytoplasm protein of cells was significantly increased in sugar-free serum-free 1.0, 3.0, and 6.0 h groups (t=43.05, 11.07, 5.39, P<0.05 or P<0.01), while the protein expression of human antigen R in the nucleus protein of cells was significantly decreased in sugar-free serum-free 3.0 and 6.0 h groups (t=11.18, 12.71, P<0.01). (4) Compared with that of simple control siRNA group, the protein expression of human antigen R in the whole protein of cells of simple HuR-siRNA1 group and simple HuR-siRNA2 group was significantly decreased (t=4.82, 4.44, P<0.05). Compared with that of sugar-free serum-free+ control siRNA group, the protein expression of human antigen R in the whole protein of cells of sugar-free serum-free+ HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA2 group was significantly decreased (t=4.39, 6.27, P<0.05). (5) Compared with those of sugar-free serum-free+ control siRNA group, the distribution of human antigen R in the cytoplasm of cells and its expression level were significantly decreased in sugar-free serum-free+ HuR-siRNA1 group (t=10.13, P<0.01). Compared with 1.00±0.06 of sugar-free serum-free+ control siRNA group, the lysosomal acidification level (0.73±0.06) in the cells of sugar-free serum-free+ HuR-siRNA1 group was significantly decreased (t=3.28, P<0.01). (6) Compared with those of sugar-free serum-free+ control siRNA group, the protein expressions of cathepsin D in the whole protein of cells, human antigen R in the cytoplasm protein of cells, and ATP6V1E1 in the whole protein of cells were significantly decreased in sugar-free serum-free+ HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA2 group (t=4.16, 3.99, 4.81, 5.07, 11.68, 12.97, P<0.05 or P<0.01). (7) Compared with that of normal control group, the mRNA expression of ATP6V1E1 in the cells of sugar-free serum-free 3.0 h group was significantly increased (t=5.51, P<0.05). Compared with that of sugar-free serum-free+ control siRNA group, the mRNA expression of ATP6V1E1 in the cells of sugar-free serum-free+ HuR-siRNA1 group was significantly decreased (t=5.97, P<0.05). Conclusions After sugar-free serum-free treatment in vitro, the autophagy in mouse primary cardiomyocytes is activated, the lysosomal acidification is enhanced, and the expression of human antigen R in cytoplasm is increased. Human antigen R function is activated and involved in maintaining lysosomal acidification during autophagy in mouse cardiomyocytes.

Objective: To explore the effects of transient receptor potential vanilloid 1 (TRPV1) on autophagy in early hypoxic mouse cardiomyocytes and the mechanism in vitro. Methods: The hearts of 120 C57BL/6 mice aged 1-2 days, no matter male or female, were isolated, and then primary cardiomyocytes were cultured and used for the following experiments, the random number table was used for grouping. (1) The cells were divided into normoxia group and hypoxia 3, 6, and 9 h groups, with one well in each group. The cells in normoxia group were routinely cultured (the same below), the cells in hypoxia 3, 6, and 9 h groups were treated with fetal bovine serum-free and glucose-free Dulbecco′ s modified Eagle medium under low oxygen condition in a volume fraction of 1% oxygen, 5% carbon dioxide, and 94% nitrogen for 3, 6, and 9 h, respectively. The protein expressions of microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, TRPV1 were determined with Western botting. (2) The cells were divided into normoxia group and hypoxia group, with two coverslips in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above. The positive expression of TRPV1 was detected by immunofluorescence assay. (3) The cells were divided into 4 groups, with one well in each group. The cells in simple hypoxia group were treated with hypoxia for 6 h as above, and the cells in hypoxia+ 0.1 μmol/L capsaicin group, hypoxia+ 1.0 μmol/L capsaicin group, and hypoxia+ 10.0 μmol/L capsaicin group were respectively treated with 0.1, 1.0, 10.0 μmol/L capsaicin for 30 min before hypoxia for 6 h. The protein expressions of LC3, Beclin-1, and TRPV1 were detected by Western blotting. (4) The cells were divided into 5 groups, with 5 wells in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above, the cells in hypoxia+ chloroquine group, hypoxia+ capsaicin group, and hypoxia+ capsaicin+ chloroquine group were treated with hypoxia for 6 h after being cultured with 50 μmol/L chloroquine, 10.0 μmol/L capsaicin, and 50 μmol/L chloroquine+ 10.0 μmol/L capsaicin for 30 min, respectively. Viability of cells was detected by cell counting kit 8 assay. (5) The cells were divided into simple hypoxia group and hypoxia+ 10.0 μmol/L capsaicin group, with one well in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above, the cells in hypoxia+ 10.0 μmol/L capsaicin group were treated with 10.0 μmol/L capsaicin for 30 minutes and then with hypoxia for 6 h. The protein expressions of lysosomal associated membrane protein 1 (LAMP-1) and LAMP-2 were detected by Western blotting. Each experiment was repeated for 3 or 5 times. Data were processed with one-way analysis of variance, least significant difference t test, and Bonferroni correction. Results: (1) Compared with those of normoxia group, the protein expressions of LC3, Beclin-1, and TRPV1 were significantly increased in cardiomyocytes of hypoxia 3, 6, and 9 h groups (t_{3 h}=4.891, 5.890, 4.928; t_{6 h}=9.790, 6.750, 10.590; t_{9 h}=6.948, 6.764, 5.049, P<0.05 or P<0.01), which of hypoxia 6 h group were the highest (1.08±0.05, 1.12±0.10, 0.953±0.071, respectively). (2) The density of TRPV1 in cell membrane and inside the cardiomyocytes in hypoxia group was significantly increased with lump-like distribution, and the expression of TRPV1 was higher than that in normoxia group. (3) Compared with those of simple hypoxia group, the protein expression of Beclin-1 in cardiomyocytes of hypoxia+ 0.1 μmol/L capsaicin group was increased (t=10.488, P<0.01), while the protein expressions of LC3 and TRPV1 were increased without statistically significant differences (t=4.372, 3.026, P>0.05); the protein expressions of LC3, TRPV1, and Beclin-1 in cardiomyocytes of hypoxia+ 1.0 μmol/L capsaicin group and hypoxia+ 10.0 μmol/L capsaicin group were significantly increased (t=15.505, 5.773, 13.430; 20.915, 8.054, 16.384; P<0.05 or P<0.01), which of hypoxia+ 10.0 μmol/L capsaicin group were the highest (2.33±0.09, 1.34±0.07, 1.246±0.053, respectively). (4) Compared with 0.585±0.045 in normoxia group, the cardiomyocyte viability in hypoxia group was significantly decreased (0.471±0.037, t=4.365, P<0.05). Compared with that in hypoxia group, the cardiomyocyte viability in hypoxia+ chloroquine group was further decreased (0.350±0.023, t=6.216, P<0.01), while 0.564±0.047 in hypoxia+ capsaicin group was significantly increased (t=3.489, P<0.05). Compared with that in hypoxia+ chloroquine group, the cardiomyocyte viability in hypoxia+ capsaicin+ chloroquine group did not significantly change (0.364±0.050, t=0.545, P>0.05). (5) Compared with 0.99±0.04 and 0.54±0.04 in simple hypoxia group, the protein expressions of LAMP-1 and LAMP-2 in hypoxia+ 10.0 μmol/L capsaicin group were significantly increased (1.49±0.06, 0.81±0.05, t=12.550, 7.442, P<0.01). Conclusions TRPV1 can further promote the expression of autophagy-related proteins in hypoxic cardiomyocytes through autophagy-lysosomal pathway, enhance autophagy activity, and improve autophagic flow for alleviating early hypoxic cardiomyocyte injury.

Background It is unclear if there is any combined effect of air pollutants and non-optimal temperature on metabolic syndrome, or any molecular mechanisms of related signaling pathways in the process, which requires urgent systematic research. Objective To observe the effects of combined exposure to PM_2.5 and non-optimal temperature on metabolic damage at gene and protein levels in mice, and elucidate the role of related signaling pathway in crucial organs. Methods A total of 60 six-week-old male C57BL/6J mice were randomly divided into six groups: a normal temperature-filter air group (T_N-FA), a normal temperature-concentrated PM_2.5 group (T_N-PM), a heat-filter air group (T_H-FA), a heat-concentrated PM_2.5 group (T_H-PM), a cold-filter air group (T_C-FA), and a cold-concentrated PM_2.5 group (T_C-PM). The Shanghai Meteorological and Environmental Animal Exposure System (Shanghai-METAS) was used to provide combined exposure settings of air types [concentrated PM_2.5 and filter air (FA)] and temperatures [normal (22°C), cold (4°C), and heat (30°C)] for 4 weeks. Skeletal muscle and white adipose tissue (WAT) of the mice were sampled at the end of exposure, and transcriptomics and Western blot (WB) assay were adopted to observe selected gene and protein expression levels in the samples respectively. Results The transcriptomics results indicated that the PM_2.5 exposure enhanced the number of differentially expressed genes. Specifically, 4820 genes were differentially expressed in the T_N-PM mice compared to the T_N-FA mice at normal temperature, and 1143 genes were differentially expressed in the Tc-PM mice compared to the Tc-FA mice in the cold environment. The phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway and the endoplasmic reticulum protein processing pathway were identified as the most significant pathways in metabolic injury resulting from combined exposure to PM_2.5 and non-optimal temperature exposure. The WB results showed that exposure to PM_2.5 in the normal temperature and the cold environments led to a significant increase in the expression of p-AKT in WAT (P<0.01, P<0.05) and a significant decrease in the expression of GLUT4 (P<0.05, P<0.01). In skeletal muscle, exposure to PM_2.5 led to a significant decrease in GLUT4 (P<0.05) in all environments, with a consistent trend of change as observed in WAT. Conclusion Cold/heat exposure might promote PM_2.5-induced metabolic disorder through suppression of the AKT/GLUT4 pathway, aggravating metabolic damage.