Molecular mechanisms underlying the BIRC6-mediated regulation of apoptosis and autophagy.

Procaspase 9 is the initiator caspase for apoptosis, but how its levels and activities are maintained remains unclear. The gigantic Inhibitor-of-Apoptosis Protein BIRC6/BRUCE/Apollon inhibits both apoptosis and autophagy by promoting ubiquitylation of proapoptotic factors and the key autophagic protein LC3, respectively. Here we show that BIRC6 forms an anti-parallel U-shaped dimer with multiple previously unannotated domains, including a ubiquitin-like domain, and the proapoptotic factor Smac/DIABLO binds BIRC6 in the central cavity. Notably, Smac outcompetes the effector caspase 3 and the pro-apoptotic protease HtrA2, but not procaspase 9, for binding BIRC6 in cells. BIRC6 also binds LC3 through its LC3-interacting region, probably following dimer disruption of this BIRC6 region. Mutation at LC3 ubiquitylation site promotes autophagy and autophagic degradation of BIRC6. Moreover, induction of autophagy promotes autophagic degradation of BIRC6 and caspase 9, but not of other effector caspases. These results are important to understand how the balance between apoptosis and autophagy is regulated under pathophysiological conditions.

[Effect of electro-acupuncture on metabolites in the cerebral cortex of ulcerative colitis rats based on Pi/Wei-brain related theory].

OBJECTIVE: To study the effect of electro-acupuncture (EA) at points along Foot Yangming Channel on metabolite of ulcerative colitis (UC) rats' cerebral cortex and to identify key metabolites by referring to Pi/Wei-brain related theory in Chinese medicine (CM). METHODS: The UC rat model was set up by dextran sulfate sodium (DSS) method. Male SD rats were randomly divided into the model group and the EA group, 13 in each group. Another 13 rats were recruited as the blank control group. Rats in the blank control group and the model group received no EA. EA was performed at Zusanli (ST36), Shangjuxu (ST37), and Tianshu (ST25) for 5 days by using disperse-dense wave. Then all rats were sacrificed. Their recto-colon and the ileocecal junction were pathomorphologically observed by light microscope and transmission electron microscope (TEM). Cerebral cortexes were extracted. Water-soluble and lipid-soluble brain tissue metabolites were respectively extracted for metabolic research using 1H nuclear magnetic resonance (1H-NMR). RESULTS: EA could obviously improve the general condition of UC model rats, decrease the value of DAI, reduce the infiltration of inflammatory cells in the intestinal tract, stabilize structures such as mitochondria, endoplasmic reticulum and so on (P <0.05). 1HNMR analysis showed that in the model group, contents of glutamic acid, cholesterol, very low density lipoproein (VLDL) in the pallium obviously decreased, while alanine and low density lipoprotein (LDL) significantly increased. After EA, levels of lactic acid, glutamic acid, total cholesterol (TC), and VLDL all increased, and levels of alanine and LDL decreased. All indices were approximate to those of the blank control group. CONCLUSION: EA at Foot Yangming channel was found to have some effect on metabolites in the brain tissue of UC model rats, which had specific metabonomic material basis and mechanism based on the Pi/Wei-brain related theory.

[Effect of electroacupuncture intervention on enteric microecology in ulcerative colitis rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on enteric microbial populations in ulcerative colitis (UC) model rats, so as to study its mechanisms underlying improving UC. METHODS: Thirty-nine male SD rats were randomly divided into control group, model group and EA group (n = 13 in each group). The UC model was established by intragstric perfusion of 4% dextran sodiumaqueous solution (DSS), once daily for 7 days. EA (15-25 Hz, 0.1 mA) was applied to bilateral "Tianshu" (ST 25), "Zusanli" (ST 36) and "Shangjuxu" (ST 37) for 10 min, once daily for 5 days. Disease Activity Index (DAI) including body weight and stool blood state was used to evaluate the animals' conditions. The rats' excrement was collected to detect the abundance and diversity of bacterial populations by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). RESULTS: In comparison with the control group, the animals' DAI score and enteric Clostridium bifermentans content were significantly increased (P < 0.05), and the abundance and diversity of bacterial populations, and contents of enteric Lachnospiraceae bacterium and Lactobacillus sp. were considerably down-regulated in the model group (P < 0.05, P < 0.01). Compared with the model group, the DAI score and enteric Clostridium bifermentans content were significantly lowered, and the abundance and diversity of bacterial populations, and contents of enteric Lachnospiraceae bacterium and Lactobacillus sp. were notably increased in the EA group (P < 0.05, P < 0.01). CONCLUSION: EA can improve DAI and the abundance and diversity of enteric bacterial microbiota in UC rats, which may be related to its protective effect on enteric microecology in UC.

[Effects of electroacupuncture of "Weishu" (BL 21) and "Zhongwan" (CV 12) on serum large molecular metabolites in functional dyspepsia rats].

OBJECTIVE: To compare the effects of electroacupuncture (EA) of Shu-acupoint "Weishu" (BL 21), Mu-acupoint "Zhongwan" (CV 12) and BL 21 + CV 12 on serum large molecular metabolites in functional dyspepsia (FD) rats. METHODS: A total of 50 Wistar rats were randomly divided into control, model, BL 21, CV 12 and BL 21 + CV 12 groups (n = 10/group). FD model was established by clamping the rats' tails for 30 min, once every 3 h, 4 times daily for 7 days. EA was applied to BL 21,CV 12, or BL 21 + CV 12, respectively for 20 min, once daily for 10 days. The rats' venous blood was collected for detecting large molecular metabolites by 1H nuclear magnetic resonance (NMR) spectrometer (Varian UnityInova, 600 MHz). Segmental integral calculus (0.04 ppm per segment) was performed from 6.0-0 ppm (longitudinal eddy-delay, LED) as defaulted 1H spectra values by using the VNMR software. Data was saved as text or excel files after normalization and then used for pattern recognition analyses. All the data were analyzed by principal component analysis (PCA) using the SIMCA-P 10.04 software (Umetrics AB, Umea, Sweden), and orthogonal signal correction and partial least squares discriminant analysis (OSC-PLS-DA). RESULTS: The rat serum proton-LED-1H NMR spectra revealed different metabolic spectra among control,model, BL 21, CV 12, and BL 21 + CV 12 groups. PCA and OSC-PLS-DA showed that compared with the normal control group, FD rats in model group displayed serum N-acetylglucoprotein (NAc) content was reduced considerably, high density lipoprotein (HDL) level decreased to a certain degree, while very low density lipoprotein (VLDL)/LDL increased significantly. In comparison with model group, VLDL/LDL was decreased in BL 21, CV 12 and BL 21 + CV 12 groups, while NAc content increased. Compared with BL 21 and CV 12 groups respectively, HDL level in BL 21 + CV 12 increased to a certain degree. CONCLUSION: EA of BL 21, CV 12 and BL 21 + CV 12 groups can reverse or relieve FD induced increase of VLDL/LDL and decrease of serum NAc level in rats, which may contribute to its function in improving symptoms of FD patients.