Role of Endoplasmic Reticulum Stress in Silica-induced Apoptosis in RAW264.7 Cells / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>We investigated the role of endoplasmic reticulum stress (ERS) in silica-induced apoptosis in alveolar macrophages in vitro.</p><p><b>METHODS</b>RAW264.7 cells were incubated with 200 μg/mL silica for different time periods. Cell viability was assayed by the MTT assay. Cell apoptosis was evaluated by DAPI staining, flow cytometry analysis, and Western blot analysis of caspase-3. Morphological changes in the endoplasmic reticulum were observed by transmission electron microscopy. The expression of ERS markers binding protein (BiP) and CCAAT-enhancer-binding protein homologous protein (CHOP) was examined by Western blotting and real-time PCR. As an inhibitor of ERS, 4-phenylbutyric acid (4-PBA) was used in the experiments.</p><p><b>RESULTS</b>Silica exposure induced nuclear condensation and caspase-3 expression in RAW264.7 cells. The number of apoptotic cells increased after silica exposure in a time-dependent manner. Silica treatment induced expansion of the endoplasmic reticulum. In addition, the expression of BiP and CHOP increased in silica-stimulated cells. Furthermore, 4-PBA treatment inhibited silica-induced endoplasmic reticulum expansion and the expression of BiP and CHOP. Moreover, 4-PBA treatment attenuated nuclear condensation, reduced apoptotic cells, and downregulated caspase-3 expression in silica-stimulated cells.</p><p><b>CONCLUSION</b>Silica-induced ERS is involved in the apoptosis of alveolar macrophages.</p>

Efficacy comparison between 5 mg perindopril arginine salt and 4 mg perindopril tert-butylamine salt for patients with mild to moderate essential hypertension / 中华心血管病杂志

<p><b>OBJECTIVE</b>To compare the efficacy and safety of 5 mg perindopril arginine salt and 4 mg perindopril tert-butylamine salt for patients with mild to moderate essential hypertension.</p><p><b>METHODS</b>The study was designed as multicenter, randomized, double-blind, active controlled trial with two parallel groups enrolling 524 participants with mild to moderate essential hypertension. After 2-week run-in period, 186 patients were enrolled and randomly treated with 5 mg perindopril arginine salt and 183 patients were enrolled and randomly treated with 4 mg perindopril tert-butylamine salt. The random sequence was generated by the I.R.I.S., and a balance was made in each center. After double-blind treatment for 8 weeks, the dose could be doubled for patients with uncontrolled BP ((SBP) ≥ 140 mmHg (1 mmHg = 0.133 kPa) or diastolic blood pressure (DBP) ≥ 90 mmHg) and patients were treated for another 4 weeks.</p><p><b>RESULTS</b>The sitting SBP was similarly decreased by (19.9 ± 17.2) mmHg in perindopril arginine group and (18.5 ± 14.7) mmHg (P = 0.000 5) in perindopril tert-butylamine group post 8 weeks treatment. Dose was doubled in 109 patients (59.9%) in perindopril arginine group and 116 patients (63.7%) in perindopril tert-butylamine group. At 12 weeks post therapy, the sitting SBP decreased by (19.8 ± 16.2) and (19.6 ± 16.3) mmHg respectively in the 2 groups. The decrease of sitting DBP was also similar in both groups (-12.0 ± 10.0) mmHg and (-11.0 ± 8.9) mmHg (P < 0.000 1), respectively. The control rate or response rate was also similar between the two groups (control rate over 8 weeks was 38.5% vs. 31.3%, 95% CI (-2.6-16.9), control rate over 12 weeks was 36.3% vs. 35.7%, 95% CI (-9.3-10.4), response rate over 8 weeks was 64.3% vs. 63.2%, 95% CI (-8.8-11.0), response rate over 12 weeks was 65.9% vs. 64.8%, 95% CI (-8.7-10.9)). Incidence of adverse events was low and similar in both therapy groups.</p><p><b>CONCLUSIONS</b>The results show that perindopril arginine salt 5 mg is as efficient as perindopril tert-butylamine 4 mg on lowering BP for patients with mild to moderate essential hypertension. Both drugs have good safety profile and are well tolerated by patients in this cohort.</p>

Effect of endoplasmic reticulum stress on the expression and osteogenic differentiation of periodontal ligament stem cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To determine the activity of endoplasmic reticulum stress (ERS) and its effect on osteogenic differentiation of periodontal ligament stem cells (PDLSC) in inflammatory microenvironment.</p><p><b>METHODS</b>PDLSC were obtained from the primary culture of the human tooth and cloned with limited diluted method. Real-time reverse transcription (RT)-PCR was used to examine the different expression of thapsigargin (TG) treated PDLSC and lipopolysaccharide (LPS) treated PDLSC. Real-time RT-PCR, alizarin red staining and cetyl pyridine chloride quantitative analyze were used to examine the osteogenic differentiation of PDLSC, TG + PDLSC, LPS + PDLSC and LPS + PDLSC + 4-PBA.</p><p><b>RESULTS</b>Protein kinase receptor like endoplasmic reticulum kinase (PERK), glucose regulated protein 78 (GRP78), transcription activation factor 4(ATF4), CCAAT/enhancer-binding protein-homologous protein (CHOP) mRNA expression in group PDLSC + TG in 6 h were respectively 1.49 ± 0.24, 2.77 ± 0.60, 1.75 ± 0.16, 2.16 ± 0.32, which were all greater than that in group PDLSC (P < 0.05). PERK, CHOP mRNA expression reached the peak at 6 h (1.76 ± 0.08, 2.31 ± 0.17) and were greater than group PDLSC (P < 0.05). ERS could suppress osteogenic differentiation of TG + PDLSC and LPS + PDLSC. The runt-related transcription factor-2 (RUNX2), alkaline phosphatase (ALP), osteocalcin (OCN) mRNA expression of group TG + PDLSC was respectively 0.73 ± 0.06, 0.01 ± 0.00, 0.20 ± 0.06 (P < 0.05). The RUNX2, ALP, OCN mRNA expression of group LPS + PDLSC was respectively 0.80 ± 0.06, 0.48 ± 0.05, 0.29 ± 0.04 (P < 0.05). The RUNX2, ALP, OCN mRNA expression of group PDLSC + TG + 4-PBA was respectively 1.10 ± 0.09, 0.74 ± 0.05, 0.67 ± 0.13, which were greater higher than that of group LPS + PDLSC (P < 0.05).</p><p><b>CONCLUSIONS</b>ERS was activated in PDLSC and suppressed osteogenic differentiation of PDLSC, which can simulate inflammatory microenvironment in vitro. This effect can be recovered by using ERS inhibitor 4-PBA.</p>

4-phenylbutyric Acid Regulates Collagen Synthesis and Secretion Induced by High Concentrations of Glucose in Human Gingival Fibroblasts

High glucose leads to physio/pathological alterations in diabetes patients. We investigated collagen production in human gingival cells that were cultured in high concentrations of glucose. Collagen synthesis and secretion were increased when the cells were exposed to high concentrations of glucose. We examined endoplasmic reticulum (ER) stress response because glucose metabolism is related to ER functional status. An ER stress response including the expression of glucose regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), inositol requiring enzyme alpha (IRE-1alpha) and phosphoreukaryotic initiation factor alpha (p-eIF-2alpha) was activated in the presence of high glucose. Activating transcription factor 4 (ATF-4), a downstream protein of p-eIF-2alpha as well as a transcription factor for collagen, was also phosphorylated and translocalized into the nucleus. The chemical chaperone 4-PBA inhibited the ER stress response and ATF-4 phosphorylation as well as nuclear translocation. Our results suggest that high concentrations of glucose-induced collagen are linked to ER stress and the associated phosphorylation and nuclear translocation of ATF-4.

Conformational Analysis of 2- [4- [5-Bromo-3-Methyl Pyridyl] Butyamino] -4-Pyrimidone

Potential energy of 2-[4-[5-Bromo-3-Methyl pyridyl] butylamino]-4-pyrimidone was calculated. This calculation suggests that most stable conformation existed at W1=220°, W2=220° and the minimum potential energy was -0.00807 kcal/mole

Pharmacokinetic profile of tert-butylaminoethanethiol

A preliminary study of the pharmacokinetic parameters of t-Butylaminoethanethiol (TBAESH) was performed after administration of a single dose (35 mg/kg) either orally or intravenously. Plasma or blood samples were treated with dithiothreitol, perchloric acid and, after filtration, submitted to further purification with anionic resin. In the final step the drug was retained on a cationic resin column, eluted with NaCl lM and detected according to the method of Ellman (1958). The results suggested a pharmacokinetic behavior related to a one open compartment model with the following values for the total drug: area under the intravenous curve (AUC i.v.): 443(+ ou -) 24.0; AUC oral: 85.5(+ ou -) 14.5 ug min.ml(elevado a -1); elimination rate constant: 0.069(+ ou -) 0.0055 min(elevado a -1), biological half-life: 10.0(+ ou -) 0.80 min; distribution volume 1.15(+ ou -) 0.15 ml/g; biodisponibility: 0.19(+ ou -) 0.02. From a pharmacokinetic standpoint, TBAESH seems to have no advantage over the analogous disulfide compound

Pharmacokinetic aspects of Tert-Butylaminoethyl disulfide, an experimental drug against schistosomiasis in mice

Um estudo preliminar da farmacocinética do t-butilamino-etil-dissulfeto foi conduzido utilizando droga fria ou radioativa em duas diferentes doses (35 e 300 mg/Kg). Amostras de plasma ou sangue foram tratadas com ditiotreiol, ácido perclórico, e, após filtraçäo, submetidas a uma subseqüente purificaçäo em um "batch" de resina aniônica. Na etapa final, a droga foi retida em coluna de resina catiônica, eluída com NaCl 1 M e detectada pelo método de Ellman (1958). Alternativamente, a droga radioativa foi detectada por cintilaçäo líquida. Os resultados correspondentes a droga total administrada na menor dose sugeriram um comportamento farmacocinético relacionado ao modelo de um compartimento aberto, com os seguintes parâmetros: área sob a curva intravenosa (ASCI.V.): 671 ñ 14; ASCoral: 150 ñ 40 microng.min.ml-1; constante de eliminaçäo: 0,07 min-1; meia-vida biológica: 9,8 min; volume de distribuiçäo: 0,74 ml/g. Para a dose mais alta, os resultados indicaram aparentemente a ocorrência de um modelo mais complexo e näo adequadamente classificado. Analisados em conjunto os resultados sugerem a ocorrência de um comportamento farmacocinético dose-dependente. A droga é absorvida e eliminada rapidamente, sendo este último processo relacionado principalmente a metabolizaçäo. A droga parece mais tóxica quando administrada via I.V. porque por esta via ela näo sobre metabolismo de primeira passagem e, é, por outro lado rapidamente distribuída para os tecidos. O nível sanguíneo máximo tolerado pelos animais parece ser de 16 microng/ml