Chun-Ri Li

Two distinct disulfide bonds formed in human heat shock transcription factor 1 act in opposition to regulate its DNA binding activity.

Under circumstances of heat stress, heat shock transcription factor 1 (HSF1) plays important roles in heat shock protein expression. In this study, an increasing concentration of dithiothreitol (DTT) was found to either enhance or inhibit the heat-induced trimerization of HSF1, suggesting the involvement of dual redox-dependent HSF1 activation mechanisms. Our in vitro experiments show that the heat-induced bonding between the cysteine C36 and C103 residues of HSF1 forms an intermolecular disulfide covalent bond (SS-I bond) and that it directly causes HSF1 to trimerize and bond to DNA. Gel filtration assays show that HSF1 can form intermolecular hydrophobic interaction-mediated (iHI-m) noncovalent oligomers. However, the lack of a trimerization domain prevents HSF1 activation, which suggests that iHI-m noncovalent trimerization is a precondition of SS-I bond formation. On the other hand, intramolecular SS-II bond (in which the C153, C373, and C378 residues of HSF1 participate) formation inhibits this iHI-m trimerization, thereby preventing SS-I bond formation and DNA binding. Thus, HSF1 activation is regulated positively by intermolecular SS-I bond formation and negatively by intramolecular SS-II bond formation. Importantly, these two SS bonds confer different DTT sensitivities (the SS-II bond is more sensitive). Therefore, a low concentration of DTT cleaves the SS-II bond but not the SS-I bond and thus improves DNA binding of HSF1, whereas a high concentration DTT cuts both SS bonds and inhibits HSF1 activation. We propose that these interesting effects further explain cellular HSF1 trimerization, DNA binding, and transcription when cells are under stress.

Ultimate strength performance of bulk carriers with various corrosion additions

In this study, various types of industry corrosion addition practices are investigated with regard to the ultimate strength performance of bulk carriers. Five types of corrosion additions, namely p...

Effects of acupuncture at Taixi acupoint (KI3) on kidney proteome.

This research explored and identified the protein composition of rat kidneys after acupuncture at the Taixi acupoint (KI3). Twelve adult male Wistar rats were randomly divided into a control group (n = 6) and an acupuncture group (n = 6). Rats in the acupuncture group received electroacupuncture on the bilateral KI3 for seven days. The kidneys were perfused with ice-cold saline and all kidney proteins were isolated. After protein sample preparation, two-dimensional gel electrophoresis (2-DE) was performed. The interesting spots were analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). There were nine protein spots with three-fold up-regulation in the kidney after the acupuncture. NAD-dependent isocitrate dehydrogenase and quinone reductase, the proteins involved in energy metabolism, the reduction of endogenous quinones, chemoprotection, and electrophilic stress, were identified. The data indicated that acupuncture at the KI3 of the kidney meridian of the foot shaoyin was able to increase NAD-dependent isocitrate dehydrogenase and quinone reductase expression in the kidney, and supported the relationship between the kidney and KI3.

Anti-diabetic Effects of Banaba Leaf Extracts (Lagerstroemia speciosa Pers.) through Solvents

This study investigated that the antidiabetic effects of banaba extracts with variety solvents selectivity in vitro and in vivo. Banaba extracts were prepared with water, 70% ethanol, 90% ethanol, 100% ethanol and water-ethanol that of extract twice times sequentially water and ethanol. Cell toxicity and insulin secretion of banaba extracts was tested by MTT (3-[4,5-dimetylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay on hamster insulinoma cell line, HIT-T15. Also we tested that insulin, body weight, blood glucose, total cholesterol, HDL-cholesterol, triglyceride and free fatty acid in streptozotocin diabetic rats. Water-ethanol extract has remarkable antidiabetic effect compare with the other banaba extracts. For water-ethanol extract has both of hydrophilic and hydrophobic antidiabetic materials from banaba. Expecially, corosolic acid, as known as unique polyphenol, has antidiabetic effect studied by many researchers till nowadays. But corosolic acid does not solve in water. Otherwise, we suggest that banaba extract of hydrophilic and hydrophobic materials (polyphenol and antioxidants) mixture more increased antidiabetic effects.

The Impacts of Along-Channel Acupuncture on the Protein Expressions of the Chloride Channel of the Rats with Myocardial Ischemia

Recent evidence suggests that chloride (CL−) channels are involved in myocardial ischemia. In this study, the impact of acupuncture on the protein expressions of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) and CLC-2 CL− channel of the rats with myocardial ischemia were tested and its mechanism was explored. The rats for experiment were distributed randomly into 5 groups: blank control group, modeling control group, Neiguan (PC-6) treatment group, Lieque (LU-7) control group, and Non-acupoint control group. The rats of all groups, except the blank control group, had myocardial ischemia via multiple subcutaneous injection of isoproterenol (ISO). Electroacupuncture treatment was given to Neiguan (PC-6) treatment group, Lieque (LU-7) control group, and Non-acupoints control group, respectively, once a day for 7 days. The results show that acupuncture can alleviate the myocardial ischemia of cardiac tissue, decrease significantly the activities of serum SOD and MDA, and thereby influence the protein expressions of CFTR and CLC-2 in CL− channels. The results of the study implies that acupuncture suppresses the pathological changes of cardiac tissue of rats with myocardial ischemia and regulates the protein expression of CFTR and CLC-2 CL− channels, which may serve as one possible mechanism to reduce myocardial ischemia.

Alpha-helix 1 in the DNA-binding domain of heat shock factor 1 regulates its heat-induced trimerization and DNA-binding

Heat shock factor 1 (HSF1) primarily regulates various cellular stress responses. The role of alpha-helix1 (H1) in its DNA-binding domain (DBD) during HSF1 activation remains unknown. Here, HSF1 lacking H1 loses its heat-induced activity, suggesting the importance of the latter. Furthermore, the CD spectra and AMBER prediction show that this H1 deficiency does not change the structure of HSF1 monomer, but does impact its heat-induced trimerization. Point mutation showed that Phe18 in H1 interacts with Tyr60, and that Trp23 interacts with Phe104 by an aromatic-aromatic interaction. Thus, the presence of H1 stabilizes the DBD structure, which facilitates the heat-induced trimerization and DNA-binding of HSF1.

The beneficial effect of electro-acupuncture given at PC6 (Neiguan-point) by the increase in cardiac transient outward K+ current channel which depends on the gene and protein expressions in artificially induced myocardial ischemia rats.

This study explored the mechanism of electro-acupuncture (EA) at PC6 to improve the heart function by regulating the cardiac transient outward potassium current (= Ito) channel in myocardial ischemia (MI). Kv1.4 is the main component of the slow Ito (Ito.s) channel. Kv4.2 and Kv4.3 are the main components of the fast Ito (Ito.f) channel. KChIP2 is a compound protein of Ito channel. In this experiment, MI was induced by injecting isoproterenol in rats, and the gene and protein expressions of Kv1.4, Kv4.2, Kv4.3 and KChIP2 were lower [The gene and protein decreased (42.8 ± 4.3)% and (37.2 ± 4.7)% respectively.] than the control rats significantly (p < 0.05). After MI induction, the MI rats were divided into three groups, including PC6, LU7 (Lieque-point) and Non-acupoint group which were acupunctured at once a day for 7 days respectively. After EA at PC6 and LU7, the gene and protein expressions showed obvious increased [EA at PC6: the gene and protein increased (50.24 ± 5.4)% and (39.14 ± 5.3)% respectively. EA at LU7: the gene and protein increased (24.6 ± 2.8)% and (22.04 ± 5.5)% respectively] and they are all higher than MI rats significantly (p < 0.05). EA at PC6 and LU7 showed the same variation, and the effects of EA at PC6 and LU7 were better than Non-acupuncture-point (p < 0.05). The effects of EA at PC6 were significantly better [The gene and protein increased (19.74 ± 2.7)% and (14.14 ± 4.4)% respectively] than LU7 (p < 0.05). PC6 is an acupoint of the pericardium meridian, and the pericardium meridian which corresponds to adrenal gland according to Omura Ys research, can affect the heart function directly LU7 belong to the lung meridian, and the lung plays an important factor in blood circulation according to TCM. So PC6 is more effective than LU7 on heart function regulation. The results suggested that PC6 showed the target effect of meridian specificity on regulating the Kv channel in MI.

Eye Acupuncture Treatment for Stroke: A Systematic Review and Meta-Analysis.

There were applications of eye acupuncture for stroke patients. Unfortunately, similar to many other Traditional Chinese Medicine (TCM) treatments, it lacks comprehensive evaluation and system review for its effect and safety. Objective. This study is a systematic review to appraise the safety and effectiveness of eye acupuncture for stroke. Methods. “Eye acupuncture therapy” in eleven databases was searched by randomized controlled trials and quasi-randomized controlled trials. The search activity was ended in April 2014. The data were extracted and assessed by three independent authors. Rev Man 5.0 software was used for data analysis with effect estimate presented as relative risk (RR) and mean difference (MD) with a 95% confidence interval. Results. Sixteen trials (1120 patients) were involved with generally poor methodological quality. The study indicated that when eye acupuncture was combined with western medicine compared to western medicine, there was a significant difference in the areas of mental state, swallow function, and NDS. When eye acupuncture was combined with western medicine and rehabilitation compared to western medicine and rehabilitation, there was significant difference in the changes of SSS, FMA, and constipation symptoms evaluation. No adverse events or side effects have been reported. Conclusions. The current evidence is insufficient and the rigorously designed trials are warranted.

Different Surface Electromyography of Propagated Sensation along Meridians Produced by Acupuncturing Quchi Acupoint (LI11) or Control Points

This study investigated the propagated sensation along meridians (PSM) produced respectively by acupuncture at a specific acupoint of right-side Quchi (LI11), a nonacupoint on meridian (control meridian point), and neither meridian nor acupoint (control point). All the stimulated points were on the right brachioradialis along the large intestine meridian of hand Yangming. Surface electromyography (sEMG) was used to reflect the activity of the brachioradialis along the large intestine meridian of hand Yangming. The PSM rate of LI11 (59.21%) and the control meridian point (53.95%) were significantly higher than the control point (38.16%) (P < 0.05). After acupuncture, the brachioradialis sEMG amplitude was 5.08 ± 2.93 uV at LI11, 3.08 ± 1.18 uV at the control point, and 2.77 ± 1.36 uV at the control meridian point. The amplitude of LI11 was significantly higher than both the control meridian point and the control point (P < 0.05). When the sEMG activity of brachioradialis returned to the stable base line, brachioradialis sEMG duration at LI11 (265 ± 87.87 s) was significantly longer than that at the control meridian point (91.69 ± 42.98 s) and the control point (83.31 ± 32.76 s) (P < 0.05). In conclusion, acupuncture activated PSM at all points but showed an acupoint specificity at LI11 and a meridian specificity at the control meridian point.