ABSTRACT
Objective:To investigate the effect of Clostridium butyricum on renal tissue of db/db mice and to explore its mechanism. Methods:Fourteen-week-old db/db mice were divided into db/db group( n=10) and db/db+ Cb group( n=7) according to random number table method. Age-matched db/m mice were selected as the normal control group. The db/m and db/db mice were administered 0.9% sodium chloride solution by gavage, while the db/db+ Cb mice were administered an equivalent amount of Clostridium butyricum solution by gavage for 8 weeks. Serum creatinine , fasting blood glucose, urinary albumin to creatinine ratio(ACR) and other biochemical indicators were also detected. HE staining was used to observe the pathological changes of kidney tissue. The expressions of peroxisome proliferators-activated receptor γ coactivator-1α(PGC-1α) mRNA were detected by realtime PCR, while the expressions of nuclear factor-κB(NF-κB), glucagon-like peptide 1 receptor(GLP-1R), and adenosine monophosphate-activated protein kinase(AMPK) in kidney tissue were determined by immunohistochemistry and Western blotting. The levels of intestinal flora, serum and fecal short-chain fatty acids(SCFAs) were measured by 16S rRNA, liquid chromatograph-mass spectrometer, and gas chromatograohy-mass spectrometry respectively. Results:Compared to db/db mice, db/db+ Cb mice showed improvement in general condition after supplementation with Clostridium butyricum. Fasting blood glucose, blood urea nitrogen, albumin-to-creatinine ratio(ACR), blood creatinine, and levels of interleukin-6(IL-6) in kidney tissue were reduced(all P<0.05). The pathology showed various degrees of amelioration of kidney tissue injury in mice. The expression of PGC-1α mRNA increased in kidney tissue( P<0.05). Decreased expression of NF-κB protein, as well as increased expression of GLP-1R and phosphorylated(p-)AMPK/AMPK protein(all P<0.05) were detected in kidney tissues. Clostridium butyricum modulated the composition of the gut microbiota with elevated total SCFAs in blood and feces. Conclusion:Clostridium butyricum increased the expression of GLP-1R in kidney tissue, promoted AMPK phosphorylation, and alleviated renal tissue damage in mice. This suggests that it may be associated with regulating the abundance of SCFA-producing bacterial populations.
ABSTRACT
@#To construct PTEN/PLGA-(HE)10-MAP nanoparticles, which encapsulated PTEN plasmid DNA and combined with the pH-responsive cell-penetrating peptides (CPPs), and to investigate their effects of gene delivery and anti-tumor targets in vitro. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles loaded with PTEN plasmid DNA were prepared by double emulsification-solvent evaporation method. PTEN/PLGA-(HE)10-MAP nanoparticles were prepared by coupling the histidine-glutamic acid-model amphipathic peptide nanocomplex [(HE)10-MAP] to the surface through amide condensation reaction. Particle size, Zeta potential, encapsulation rate and drug loading were tested to characterize the nanoparticles. By analyzing the cytotoxicity, cellular uptake, targeted transfection of eukaryotic expression plasmids and anti-tumor cell proliferation, the feasibility as a targeted gene delivery system were evaluated. The particle size of PTEN/PLGA-(HE)10-MAP nanoparticles was (266.5 ± 2.86) nm, with the encapsulation efficiency (80.6 ± 6.11)%. Zeta potentials were -(6.7 ± 0.26) mV, +(0.7 ± 0.22) mV and +(37.5 ± 0.85) mV at pH 7.4, 7.0 and 6.5, respectively. In the cytotoxicity test, the cell survival rates of tumor and normal cells were above 80%.Non-loading PLGA-(HE)10-MAP nanoparticles showed no obvious cytotoxicity. The results of cellular uptake experiments showed that PTEN/PLGA-(HE)10-MAP nanoparticles were more readily taken up by cells.The results of CCK-8 showed that the nanoparticles could pH-specifically inhibit proliferation of tumor cell in vitro.And PTEN/PLGA-(HE)10-MAP nanoparticles may be applied in tumor gene therapy.
ABSTRACT
@#This study aimed to construct a DC-targeted aptamer-modified Pseudomonas aeruginosa(PA)DNA vaccine delivery system. The cationic liposome was prepared by ethanol injection method. The cationic liposome loading pVAX1-OprF-VP22(Lip-pOprF-VP22)was prepared by electrostatic adsorption method. The encapsulation efficiency of Lip-pOprF-VP22 with different mass ratios of DOTAP/pDNA on pVAX1-OprF-VP22, cytotoxicity and transfection rate to DC2. 4 in vitro were discussed. The particle size and zeta potential of Lip-pOprF-VP22 with best mass ratio were tested. Aptamer-modified cationic liposome loading pVAX1-OprF-VP22(Apt-Lip-pOprF-VP22)was prepared by post-insertion method. The expression of OprF protein after transfection of DC2. 4 and its effect on the maturation of bone marrow-derived dendritic cells(BMDCs)were detected. Data showed that as the mass ratio of DOTAP/pDNA increased, the encapsulation efficiency of Lip-pOprF-VP22 on pVAX1-OprF-VP22 was gradually increased. When the mass ratio was 5 ∶1, pVAX1-OprF-VP22 was encapsulated well. When Lip-pOprF-VP22 with different mass ratios was applied to DC2. 4 for 24 h or 48 h, the survival rates of DC2. 4 were all above 80%. When the mass ratio of DOTAP/pDNA increased from 2 ∶1 to 10 ∶1, the transfection rate increased first and then decreased. When the mass ratios of DOTAP/pDNA were 4 ∶1 and 5 ∶1, the transfection rates were relatively high. When the mass ratio of DOTAP/pDNA was 5 ∶1, the particle size of Lip-pOprF-VP22 was(171. 67±1. 27)nm, and the Zeta potential was(11. 30±0. 57)mV. Furthermore, Apt-Lip-pOprF-VP22 can express more OprF protein and significantly promote the maturation of BMDCs. In conclusion, Apt-Lip-pOprF-VP22 can target to DC and promote the maturation of DC.