Limited accumulation of high-frequency somatic mutations in a 1700-year-old Osmanthus fragrans tree.

Lifespan varies greatly between and within species. Mutation accumulation is considered an important factor explaining this life-history trait. However, direct assessment of somatic mutations in long-lived species is still rare. In this study, we sequenced a 1700-year-old sweet olive tree and analysed the high-frequency somatic mutations accumulated in its six primary branches. We found the lowest per-year mutation accumulation rate in this oldest tree among those studied via the whole-genome sequencing approach. Investigation of mutation profiles suggests that this low rate of high-frequency mutation was unlikely to result from strong purifying selection. More intriguingly, on a per-branching scale, the high-frequency mutation accumulation rate was similar among the long-lived individuals such as oak, wild peach and sweet olive investigated here. We therefore suggest the possibility that the accumulation of high-frequency somatic mutations in very long-lived trees might have an upper boundary due to both the possible limited number of stem cell divisions and the early segregation of the stem cell lineage.

Tectorigenin alleviates intrahepatic cholestasis by inhibiting hepatic inflammation and bile accumulation via activation of PPARγ.

BACKGROUND AND PURPOSE: Increasing evidence suggests that human cholestasis is closely associated with the accumulation and activation of hepatic macrophages. Research indicates that activation of PPARγ exerts liver protective effects in cholestatic liver disease (CLD), particularly by ameliorating inflammation and fibrosis, thus limiting disease progression. However, existing PPARγ agonists, such as troglitazone and rosiglitazone, have significant side effects that prevent their clinical application in the treatment of CLD. In this study, we found that tectorigenin alleviates intrahepatic cholestasis in mice by activating PPARγ. EXPERIMENTAL APPROACH: Wild-type mice were intragastrically administered α-naphthylisothiocyanate (ANIT) or fed a diet containing 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) to simultaneously establish an experimental model of intrahepatic cholestasis and tectorigenin intervention, followed by determination of intrahepatic cholestasis and the mechanisms involved. In addition, PPARγ-deficient mice were administered ANIT and/or tectorigenin to determine whether tectorigenin exerts its liver protective effect by activating PPARγ. KEY RESULTS: Treatment with tectorigenin alleviated intrahepatic cholestasis by inhibiting the recruitment and activation of hepatic macrophages and by promoting the expression of bile transporters via activation of PPARγ. Furthermore, tectorigenin increased expression of the bile salt export pump (BSEP) through enhanced PPARγ binding to the BSEP promoter. In PPARγ-deficient mice, the hepatoprotective effect of tectorigenin during cholestasis was blocked. CONCLUSION AND IMPLICATIONS: In conclusion, tectorigenin reduced the recruitment and activation of hepatic macrophages and enhanced the export of bile acids by activating PPARγ. Taken together, our results suggest that tectorigenin is a candidate compound for cholestasis treatment.

[Influence of huatanjiangqi prescription on multidrug resistance-associated protein 1 in human bronchial epithelial cells].

OBJECTIVE: To investigate the effect of Huatanjiangqi prescription (Sinapis Semen, Perillae Fructus, Cynanchi Stauntonii Rhizoma et Radix, Inulae Herba, Angelicae Sinensis Radix, Honey-fried Ephedrae Herba) on multidrug resistance-associated protein 1 (MRP1) in human bronchial epithelial cells. METHODS: The human bronchial epithelial cells line 16HBE140- was used to analyze the in vitro effect of Huatanjiangqi prescription on MRP1 transport. 5-CFDA was used as a model MRP1 substrate and was measured with flow cytometry. The mRNA expression of MRP1 was detected by real-time PCR. RESULTS: Huatanjiangqi prescription could promote the proliferation of human bronchial epithelial cells 16HBE140- in a certain range of concentration; Compared with the control group (5-CFDA), low, medium and high concentration (100, 1 000, 2 000 microg/mL) of Huatanjiangqi prescription on MRP1 function were increased by 22.59%, 47.14% and 68.36%, respectively; Huatanjiangqi prescription could concentration-dependently induce the expression of MRP1 mRNA, medium and high concentration could induce a significant difference. CONCLUSION: Huatanjiangqi prescription can improve MRP1 efflux function and mRNA levels in a concetration-dependent manner.

Allyl isothiocyanate increases MRP1 function and expression in a human bronchial epithelial cell line.

Multidrug resistance-associated protein 1 (MRP1), a member of the ATP-binding cassette (ABC) superfamily of transporters, plays an important role in normal lung physiology by protecting cells against oxidative stress and toxic xenobiotics. The present study investigates the effects of allyl isothiocyanate (AITC) on MRP1 mRNA and MRP1 protein expression and transporter activity in the immortalised human bronchial epithelial cell line 16HBE14o-. MRP1 mRNA and MRP1 protein expression in 16HBE14o- cells that were treated with allyl isothiocyanate were analysed by real-time PCR assay and Western blotting. The transport of carboxyfluorescein, a known MRP1 substrate, was measured by functional flow cytometry to evaluate MRP1 activity. Treatment with AITC at concentrations of 5-40 µM increased MRP1 protein levels in a concentration-dependent manner. AITC treatments at concentrations of 1-40 µM caused concentration-dependent increases in MRP1 mRNA levels that were up to seven times greater than the levels found in control cells. Finally, AITC treatment at concentrations of 5-40 µM significantly increased MRP1-dependent efflux in 16HBE14o- cells. These results suggest that AITC can increase the expression and activity of MRP1 in 16HBE14o- cells in a concentration-dependent manner. The upregulation of MRP1 activity and expression by AITC could produce therapeutic effects in the treatment of lung disease.

The pharmacokinetics and conversion of the lactone to the carboxylate forms of ginkgolide B in rat plasma.

Ginkgolide B consists of three lactone groups, which may undergo hydrolysis, and lead to the rings opening in aqueous solution with different pHs. From mechanisms of pharmacological activity in vivo, the lactone appears to be the active form of the drug. Pharmacokinetics of lactone form (GB-lac) and the total of the lactone and carboxylate form (GB-tot) of ginkgolide B were investigated after intravenous administration of a dose of 4 mg/kg ginkgolide B. The rate of lactone hydrolysis was also studied in plasma in vitro. After intravenous administration, ginkgolide B in the original form was converted to its carboxylate form under simulated physiological conditions. The AUC0 - ∞ of GB-lac constituted 63.5 ± 17.4% of the AUC0 - ∞ of GB-tot. The ratio of average cumulation of excretion of lactone to carboxylate reached approximately 1 to 1 in urine. From the equilibrium of lactone hydrolysis in rat plasma in vitro, the k obs was - 0.0176 min(- 1) and t 1/2 was 39.38 min. In conclusion, the equilibrium existed between lactone of ginkgolide B and its carboxylate form in vivo at physiological pH, which suggested that more attention should be focused on the original and the ionization forms of ginkgolide B and the conversion of the lactone into carboxylate in vivo.

[Effects of huatan jiangqi capsule on the levels of multi-drug resistance-associated protein 1 in the bronchial epithelial cells of model rats with chronic obstructive pulmonary disease].

OBJECTIVE: To observe the effects of huatan jiangqi capsule (HJC) on the expression levels and functions of multi-drug resistance-associated protein 1 (MRP1) in the bronchial epithelial cells of chronic obstructive pulmonary disease (COPD) model rats, and to explore the mechanism of HJC for treating COPD. METHODS: Twenty-four male wistar rats were randomly divided into the normal control group, the model group, and HJC group. Except the normal control group, the COPD rat model was established in the rest groups using quantitative stimulation with tobacco, SO2, and caroid aerosol rebreathing method. The indices of the post-treatment lung functions, the cell counts of bronchoalveolar lavage fluid (BALF), the pathological features of the lung tissue were observed. The concentration of LTC, in lung tissues was also examined by ELISA. The expression of MRP1 of the pulmonary tracheal epithelium was detected using immunohistochemical assay. RESULTS: (1) The pulmonary compliance, the forced expiratory volume at 0. 3 second (FEV 0.3%)/the forced vital capacity (FVC), the peak expiratory flow, the maximum mid expiratory flow decreased more significantly in the model group than in the normal control group (P < 0.05). The aforesaid pulmonary function indices obviously increased in the HJC group when compared with the model group (P < 0.05). (2) The air inflammation was aggravated with obvious emphysema in the model group. The inflammation and emphysema occurred in the HJC group in a milder degree. (3) Compared with the normal control group, the levels of LTC4 significantly increased in the lung tissue of the model group and HJC group (P < 0.01). Compared with the model group, the levels of LTC4 significantly decreased in the lung tissues of the HJC group (P < 0.05). (4) Compared with the normal control group, the protein expression of the bronchial epithelial MRP1 significantly decreased in the model group (P < 0.01). Compared with the model group, the protein expression of the bronchial epithelial MRP1 were significantly enhanced in the HJC group (P < 0.05). CONCLUSION: HJC could effectively alleviate the lung inflammation, postpone the occurrence and development of COPD possibly through effecting the functions and expressions of MRP1 in COPD rats.