A lipophilic prodrug of Danshensu: preparation, characterization, and in vitro and in vivo evaluation.

Danshensu [3-(3, 4-dihydroxyphenyl) lactic acid, DSS], one of the significant cardioprotective components, is extracted from the root of Salvia miltiorrhiza. In the present study, an ester prodrug of Danshensu (DSS), palmitoyl Danshensu (PDSS), was synthesized with the aim to improve its oral bioavailability and prolong its half-life. The in vitro experiments were carried out to evaluate the physicochemical properties and stability of PDSS. Although the solubility of PDSS in water was only 0.055 mg·mL-1, its solubility in FaSSIF and FeSSIF reached 4.68 and 9.08 mg·mL-1, respectively. Octanol-water partition coefficient (log P) was increased from -2.48 of DSS to 1.90 of PDSS. PDSS was relatively stable in the aqueous solution in pH range from 5.6 to 7.4. Furthermore, the pharmacokinetics in rats was evaluated after oral administration of PDSS and DSS. AUC and t1/2 of PDSS were enhanced up to 9.8-fold and 2.2-fold, respectively, compared to that of DSS. Cmax was 1.67 ± 0.11 µg·mL-1 for PDSS and 0.81 ± 0.06 µg·mL-1 for DSS. Thus, these results demonstrated that PDSS had much higher oral bioavailability and longer circulation time than its parent drug.

Associations of maternal PLA2G4C and PLA2G4D polymorphisms with the risk of spontaneous preterm birth in a Chinese population.

Preterm birth is the leading cause of mortality and morbidity in infants. Its etiology is multifactorial with genes and immune homeostasis. The authors investigated whether prostaglandin (PG) synthesis related single nucleotide polymorphisms (SNPs) PLA2G4C rs1366442 and PLA2G4D rs4924618 were associated with the risk of spontaneous preterm birth (SPTB) in a Chinese population of 114 cases of SPTB and 250 controls of term delivery. The risk associations were determined by odds ratios (ORs) and their 95% confidence intervals (CIs) calculated using multivariate logistic regression. Homology modeling was performed to elucidate potential mechanism of the SNP function. The maternal AT/TT genotype of PLA2G4D rs4924618 was associated with a reduced risk of SPTB (OR, 0.61; 95% CI, 0.37­0.99), while no significant association between PLA2G4C rs1366442 and SPTB risk was identified. Structure and sequence analysis revealed that the amino acid substitution introduced by this SNP located at the conserved central core of the catalytic domain of cytosolic phospholipase A2 δ and was close to the active site. These findings suggested that the polymorphism of PLA2G4D rs4924618 may have a protective influence on the SPTB susceptibility in a Chinese population, supporting a role for genetics in the association between PG synthesis and preterm birth.

Maternal IGF1 and IGF1R polymorphisms and the risk of spontaneous preterm birth.

BACKGROUND: The insulin-like growth factor (IGF) pathway was involved in the occurrence of spontaneous preterm birth (SPTB), but little is known regarding the relationship between genetic variations in IGF pathway and the risk of SPTB. We aimed to investigate the associations of IGF1 rs972936 and IGF1 receptor (IGF1R) rs2229765 polymorphisms with SPTB risk in a Chinese population. METHOD: A total of 114 cases of SPTB and 250 controls of term delivery were included from Guangzhou Women and Children's Medical Center, China. The odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were calculated using multivariate logistic regression. RESULTS: We found that the GA and GA/AA genotypes of IGF1 rs972936 were associated with an increased risk of SPTB, and the adjusted ORs (95% CI) were 1.74 (1.01-3.02) and 1.75 (1.04-2.93) respectively. Women carrying GA and GA/AA genotypes of IGF1R rs2229765 had a reduced risk compared to those with the GG genotype (0.60 [0.37-0.98] and 0.64 [0.40-1.00] respectively). There were significant interactions between IGF1 rs972936 and GDM status (P for interaction=.02), as well as between IGF1R rs2229765 and pre-pregnancy BMI (P for interaction <.001) on the risk of SPTB. CONCLUSION: Our findings suggest that polymorphisms of IGF1 rs972936 and IGF1R rs2229765 were associated with the risk of SPTB in Chinese pregnant women and these effects depend on the maternal metabolic status.

[SIRT1 promote GTM cell DSBs repair and resist cellular senescence].

OBJECTIVE: To study the relationship between SIRT1 and glaucoma trabecular meshwork cell (GTM) cell on DNA double-strand breaks (DSBs) repair capability and resist cellular senescence. METHODS: The expressions of SIRT1 in GTM and normal trabecular meshwork (HTM) cell detected by RT-RCR and Western blot; HTM and GTM cells divided into four groups separately: Res group (treat cells with 0.5 micromol/L Resveratrol for 24 h), SIRT1-ShRNA group (cells infected with recombinant SIRT1-ShRNA), microRNA34a group (cells infected with recombinant microRNA34a) and control group. The expression level of SIRT1 in groups was detected by Western blot. SA-beta-Gal staining was applied to each group of cells at 10 h, 32 h, 3 d and 6 d to evaluate the senescence of the cells. DSBs and the expression of gamma-H2AX after treated with 1.33 mol/L H2O2 at 0 h, 1 h, 2 h were detected by comet electrophoresis and Western blot. RESULTS: The expression of SIRT1 were observed in both HTM and GTM cells, but the expression level in HTM was higher than that of GTM cells have the ability to express SIRT1, however the expression of SIRT1 was lower than HTM. Expression levels of SIRT1 presented following treads: Res > Control > microRNA34a > SIRT1-ShRNA. The dgree of senescence in GTM was higher than that in HTM cells when detected at the same time point with SA-beta-Gal staining. In the same cell line, the signs of senescence were appeared firstly and seriously in the cells treated with SIRT1-ShRNA in a time-dependent manner. Differently, after 24 h treatment with Res, the degree of senescence was decreased. The DSBs in GTM group was more than that of HTM group after treatment with oxidant when detected with Comet Electrophoresis and the the trends of the change was SIRT1-ShRNA > microRNA34a > Control > Res. The similar results also observed in the expression of gamma-H2AX. CONCLUSION: SIRT1 may be useful in predicting the development and prognosis of glaucoma; Res promotes the expression of SIRT1 significantly, and the SIRT1 may protects GTM from oxidative stress-induced DSBs, aging even apoptosis, and promotes cell cycle arrest, which may provide a new target to treat glaucoma.

[The study of esophageal cancer risk associated with polymorphisms of DNA damage repair genes XRCC4 and RAD51].

OBJECTIVE: Investigate the association between genetic polymorphism of DSBs repair gene XRCC4, RAD51 and susceptibility to esophageal cancer (EC). METHODS: A hospital based case-control study with 123 EC cases and 61 controls in a Chinese population was conducted. PCR-RFLP was applied to investigate the genotype of XRCC4 promoter G-1394T (rs6869366) and RAD51-G135C and then statistical analysis was conducted by calculating the adjusted odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS: A significant difference of XRCC4-1394 polymorphism was observed between EC cases and controls (P < 0.05). Carriers of the XRCC4 rs6869366 G allele (GC+GG) were at a higher risk of developing EC with the TT genotype as reference (OR = 3.022, 95% CI = 1.487-6.142, P = 0.002). When GG served as the reference group of RAD51-G135C allele, variant genotype (GC and CC) had a significant increased risk of lung cancer (OR = 3.643, 95% CI = 1.501-8. 842, P < 0.05). CONCLUSION: Our findings indicated that genetic variants in DNA repair pathways may be involved in esophageal tumorigenesis. XRCC4 G-1394T and RAD51-G135C conferred risk for the process of developing EC.

[Research on regulation of cell senescence by miRNA-34a].

OBJECTIVE: To determine miRNA-34a regulated cell senescence indirectly through targeting silent mating-type information regulation 2 homologue 1 (SIRT1) in vitro experiment. METHODS: A constructed pre-miRNA -34a expression vector and a miRNA-1792 expression vector (not directly against any gene) were transfected into HEK293 and HUVEC cell lines respectively. The expression levels of SIRT1 in each cell groups were detected by RT-PCR and Western blot. The HUVEC cells were divided into different group: transfected with pre-miRNA-34a expression vector (HUVEC-pre-miRNA-34a), transfected with miRNA-1792 expression vector (HUVEC-pre-miRNA-1792), treated HUVEC cell with SIRT1 activator resveratrol (final concentration 1 micromol/L, treatment for 2 h)(HUVEC-Res), and HUVEC cells without any treatment as the control. Comet assay was applied to detect the oxidative damage of above-mentioned cells after H2O2 treatment for 2 h, and beta-galactosidase (SA-beta-gal) staining was used to detect the senescence of them in different time points after doxorubicin treatment for 2 h. RESULTS: Pre-miRNA-34a expression vector was constructed successfully by sequencing confirmation. RT-PCR and Western blot indicated that the overexpression of miRNA-34a down regulated mRNA and protein level of SIRT1 in HEK293-miRNA-34a and HUVEC-miRNA-34a cell groups (P < 0.001). Comet assay revealed that HUVEC-miRNA-34a cell group was the most sensitive to H2O2 treatment, and the DNA damage of HUVEC-Res cell group was the most minor. HUVEC-miRNA-34a cell group displayed higher frequency of SA-beta-gal staining than that of other cell groups. CONCLUSION: miRNA-34a regulated cell senescence indirectly through targeting SIRT1.

[The study of hydrogen peroxide induced DNA damage and recovery in normal aging and premature aging human cells].

OBJECTIVE: To study the DNA damage and recovery induced by hydrogen peroxide in normal aging and premature aging human cells. METHODS: The immunofluorescent assay and comet assay were used to estimate basal DNA damage in normal aging BJ cells and premature aging Hutchinson-Gilford progeria syndrome (HGPS) cells, which were divided into three and two distinct population doubling (PD) number groups (BJ 14, 30, 45 and HGPS 8, 17) respectively. The DNA damage induced by hydrogen peroxide of these cell populations, as well as their repair activity, was also studied. Finally, the recovery capability before and after the xeroderma pigmentosum group A (XPA) knocked down in these groups was measured. RESULTS: Our results indicated that the normal BJ cells of older PD number showed higher basal levels of DNA damage and were more sensitive to the effects of the DNA-damaging agents than the adult one, who, in turn, was more sensitive than the younger ones. The basal damage level of HGPS cells was same or higher than the older BJ cells. HGPS cells also had the same consistent damage change as BJ cells after treatment. The decline of the repair efficiency with age to the DNA damage induced by the agent was also observed. CONCLUSION: The DNA repair of HGPS is repressed by dysfunction of XPA.

[Study of flavanoids extracted from onion on the blood-brain barrier permeation and neuroprotective effects].

OBJECTIVE: To study the flavanoids extracted from onion on the blood-brain barrier (BBB) permeation, and their effects on primary cultured neuron cell proliferation and apoptosis of SD rats using ethanol reflux method. METHODS: The brain microvascular endothelial cells (BMVECs) were first successfully primary cultured. Then rats BMVECs and astrocytes (ACs) were co-cultured to establish the in vitro BBB model. The flavanoids were extracted from onion using ethanol reflux method. The model was verified by transmission electron microscopy (TEM) and trans-epithelial electric resistance (TEER). The flavanoids permeability was tested using high performance liquid chromatography (HPLC). Meanwhile, rat neuron cells were cultured and exposed to H2O2 and flavanoids. Their effects on the cell proliferation and apoptosis were observed using MTT assay. The injury of neuron DNA was analyzed using single-cell gel electrophoresis (SCGE) and immunofluorescent assay. RESULTS: The in vitro BBB model was successfully established by TEM and TEER. Results of HPLC proved flavanoids extracts could effectively permeate the BBB with the permeability of 60.58%. The extractive at 10 - 20 microg/mL showed obvious inhibition on the apoptosis of neuron cells induced by H2O2, and attenuated the injury of neuron DNA. CONCLUSIONS: The flavanoids extracted from onion ethanol reflux method could effectively penetrate the BBB. They also showed obvious inhibition on the H2O2 induced neuron cell apoptosis and DNA injury.

[Association of XPC and XPG polymorphisms with the risk of hepatocellular carcinoma].

OBJECTIVE: To investigate whether the polymorphism of DNA repair genes XPC (Ala499Val and Lys939Gln) and XPG (His1104Asp) is associated with the susceptibility to hepatocellular carcinoma (HCC). METHODS: A hospital-based case-control study was conducted in 500 cases with HCC and 507 controls. Genotypes of XPC and XPG were determined by real-time polymerase chain reaction with the TaqMan MGB probe. RESULTS: Compared to the CC genotype, the CT genotype and the TT genotype of XPC Ala499Val were not associated with the susceptibility to HCC (adjusted OR = 1.34, 95% CI: 0.85-2.12; adjusted OR = 1.30, 95% CI: 0.68-2.51, respectively). Compared to the AA genotype, the AC genotype and the CC genotype of Lys939Gln were not associated with the susceptibility to HCC (adjusted OR = 1.20, 95% CI: 0.78-1.85; adjusted OR = 1.81, 95% CI: 0.88-3.73, respectively). Compared to the CC genotype, the CG genotype and the GG genotype of XPG His1104Asp were not associated with the susceptibility to HCC (adjusted OR = 0.85, 95% CI: 0.56-1.27; adjusted OR = 1.12, 95% CI: 0.67-1.87, respectively) However, the stratified analysis revealed that the females with the AC+CC genotype of XPC Lys939Gln had increased risk of HCC compared to those with AA genotype (OR = 2.17, 95% CI: 1.01-4.64). CONCLUSION: Our results suggest that XPC and XPG polymorphisms do not independently affect on the susceptibility to HCC, but the joint effect of C allele of XPC Lys939Gln and female may modify the risk of HCC.