FGF21 induces autophagy-mediated cholesterol efflux to inhibit atherogenesis via RACK1 up-regulation.

Fibroblast growth factor 21 (FGF21) acts as an anti-atherosclerotic agent. However, the specific mechanisms governing this regulatory activity are unclear. Autophagy is a highly conserved cell stress response which regulates atherosclerosis (AS) by reducing lipid droplet degradation in foam cells. We sought to assess whether FGF21 could inhibit AS by regulating cholesterol metabolism in foam cells via autophagy and to elucidate the underlying molecular mechanisms. In this study, ApoE-/- mice were fed a high-fat diet (HFD) with or without FGF21 and FGF21 + 3-Methyladenine (3MA) for 12 weeks. Our results showed that FGF21 inhibited AS in HFD-fed ApoE-/- mice, which was reversed by 3MA treatment. Moreover, FGF21 increased plaque RACK1 and autophagy-related protein (LC3 and beclin-1) expression in ApoE-/- mice, thus preventing AS. However, these proteins were inhibited by LV-RACK1 shRNA injection. Foam cell development is a crucial determinant of AS, and cholesterol efflux from foam cells represents an important defensive measure of AS. In this study, foam cells were treated with FGF21 for 24 hours after a pre-treatment with 3MA, ATG5 siRNA or RACK1 siRNA. Our results indicated that FGF21-induced autophagy promoted cholesterol efflux to reduce cholesterol accumulation in foam cells by up-regulating RACK1 expression. Interestingly, immunoprecipitation results showed that RACK1 was able to activate AMPK and interact with ATG5. Taken together, our results indicated that FGF21 induces autophagy to promote cholesterol efflux and reduce cholesterol accumulation in foam cells through RACK1-mediated AMPK activation and ATG5 interaction. These results provided new insights into the molecular mechanisms of FGF21 in the treatment of AS.

Zirconium phosphatidylcholine-based nanocapsules as an in vivo degradable drug delivery system of MAP30, a momordica anti-HIV protein.

An essential in vivo drug delivery system of a momordica anti-HIV protein, MAP30, was developed through encapsulating in chemically synthesized matrices of zirconium egg- and soy-phosphatidylcholines, abbreviated to Zr/EPC and Zr/SPC, respectively. Matrices were characterized by transmission electron microscopy and powder X-ray diffractometry studies. Zr/EPC granule at an approximate diameter of 69.43±7.78 nm was a less efficient encapsulator than the granule of Zr/SPC. Interlayer spacing of the matrices encapsulating MAP30 increased from 8.8 and 9.7 Å to 7.4 and 7.9 nm, respectively. In vivo kinetics on degradation and protein release was performed by analyzing the serum sampling of intravenously injected SPF chickens. The first order and biphasic variations were obtained for in vivo kinetics using equilibrium dialysis. Antimicrobial and anti-HIV assays yielded greatly decreased MIC50 and EC50 values of nanoformulated MAP30. An acute toxicity of MAP30 encapsulated in Zr/EPC occurred at a single intravenous dose above 14.24 mg/kg bw in NIH/KM/ICR mice. The folding of MAP30 from Zr/EPC sustained in vivo chickens for more than 8 days in high performance liquid chromatography assays. These matrices could protect MAP30 efficiently with strong structure retention, lowered toxicity and prolonged in vivo life.

Study of CT pulmonary angiography technique in pulmonary embolism-low dose and low concentration / 中华放射学杂志

Objective To evaluate the image quality and the diagnostic value of low radiation,low dose and isotonic low concentration iodine contrast pulmonary computed tomography angiography (CTPA) protocol in pulmonary embolism.Methods Eighty patients with clinic ally suspected pulmonary embolism and BMI＜28 kg/m2 underwent pulmonary CTA on a 64-MDCT scanner (GE Discovery CT750 HD).Eighty patients were divided into two groups (group A:n=40,80 kV,Auto mA,20 ml 270 mg I/ml,60％FBP+40％ ASIR; group B:n=40,120 kV,Auto mA,40 ml 370 mg I/ml,100％FBP).Image quality was assessed,using a five-point scoring scale.Intraarterial density was measured in the common pulmonary artery trunk,the main right and left pulmonary arteries,lobar arteries,and then the average CT value was calculated.Image quality score,Average CT value,noise,SNR,CNR,CTDIvol and DLP were compared between the two groups using t-test.The occurrence rate of the superior vena cava iodine contrast agent sclerosis artifacts and the positive rate of pulmonary embolism were compared between the two groups,using Chi-square test.Results PE was found in 33 patients (14 in group A,19 in group B),and there was no difference of the positive rate of PE between two groups (35.0％ vs 47.5％,x2=1.289,P＞0.05).Overall 4-6 pulmonary artery branches were clearly displayed in all the cases.The image quality scores for two groups were 3.9±0.6 and 4.0 ± 0.7,respectively.There was no statistical difference between two groups (t=0.632,P＞0.05).The superior vena cava iodine contrast agent sclerosis artifacts were reduced in group A (28 cases vs.36 cases,x 2=10.362,P＜0.01).The average CT value and noise in group A [(426.8 ± 84.8),(14.9 ± 1.5)HU,respectively] was higher than those in group B [(359.4±75.3),(7.4± 1.4)HU,respectively],which was statistically significant(t=3.758,22.848,respectively; P＜0.01).However,the SNR (28.8 ±6.3)and CNR (24.5±6.1) in group A were lower than those in group B(SNR 50.4± 14.7,CNR 42.9± 13.8).There was statistically significant difference between two groups (t=8.522,7.669,respectively; P＜0.01 both).The CTDIvol[(3.3±0.3)mGy]and DLP[(101.4± 11.9)mGy· cm] in group A were significantly lower than those in group B [CTDI vol (9.6±0.6)mGy,DLP (328.5 ± 37.3)mGy· cm].The difference between two groups was statistically significant(t=56.393,36.675,respectively,P＜0.01 both).Conclusions The low radiation,low dose and isotonic low concentration iodine contrast CTPA protocol shows pulmonary artery branches of 4-6 levels,reduces radiation exposure and contrast media volume compared with the conventional pulmonary CTA,and achieves the same positive rate of PE in comparison of the conventional CTPA.It can meet the clinical needs.

Effect of infection with Toxoplasma gondii on the complement regulatory proteins in the mouse placenta / 中华微生物学和免疫学杂志

Objective To investigate the expression of complement regulatory proteins on placentas of pregnant C57BL/6 mice infected with Toxoplasma gondii in order to explore the molecular immunological mechanism for abnormal pregnancy induced by T. gondii infection. Methods Twenty-four pregnant C57BL/6 mice were randomly divided into two groups equally. The infection group was intraperitoneally injected with 200 of living T, gondii RH strain tachyzoites on the 8th day of gestation, and the normal group of mice was injected with physiological saline. All mice were killed on day 14 after gestation and placentas were collected. The expression levels of Crry, GPI-DAF and CD59a mRNA were analyzed by real-time quantitative PCR, and the positive rates of Crry and GPI-DAF were measured with flow cytometry. Results The died fetus rates of infected group and control were 80. 95% and 4. 41% , respectively. The infected group was significantly higher than of that the control group (P＜0.01). The expression levels of Crry, GPT-DAF and CD59a mRNA in the infected and control group were 0.786 ±0. 199, 0.594 ±0.096, 0.880 ±0. 179 and 0.550 ±0.077, 0.221 ±0.074, 0.591 ± 0.075 , respectively, and the difference of three kind of complement regulation proteins between two groups was all significant (P＜0.01). The positive percentages of Crry and GPI-DAF cells of infected and control group were (10. 03 ± 2. 11) % , (2.95 ±1.04)% and (3. 15 ± 1. 32) % , (0. 66 ±0. 26) % , respectively, and the difference of the two kind complement regulation proteins between two groups was also significant ( P ＜ 0. 01). Conclusion The expression level of mouse placental complement regulatory proteins was increased after infection with T. gondii, and then immunological microenvironment at the fetomaternal interface was destroyed. It may be one of important immunological mechanism for abnormal pregnancy induced by T. gondii infection.

Study on the immunogenicity of Schistosoma japonicum mitochondria related protein / 中华传染病杂志

Objective To identify the immunogenicity and the potential of using Schistosoma japonicum mitochondria related protein(rSj338) as a candidate vaccine antigen for Schistosomiasis japonica . Methods The expressed recombinant fusion protein(rSj338/26GST) was purified and recognized by S.japonicum heavily infected rabbit sera and rSj338/26GST immunized rabbit sera by Western blotting. The inclusion bodies,the revivified protein and the purified protein from S 12 gel filtration were injected twice into rabbits to produce anti rSj338/26GST antibody which titer was then measured by dot ELISA. Balb/c mice were immunized with the inclusion bodies and the purified protein from S 12 gel filtration and challenged with S. japonicum cercariae to identify the protective immunity produced by rSj338/26GST. Results The inclusion bodies, the revivified protein and the purified protein from S 12 gel filtration could stimulate the rabbits to produce high level of anti rSj338/26GST antibodies and could be recognized by S. japonicum heavily infected rabbit sera and rSj338/26GST immunized rabbit sera. In Balb/c mice, the inclusion bodies could induce 27.8%( P