Antioxidative systems, metal ion homeostasis and cadmium distribution in Iris lactea exposed to cadmium stress.

Iris lactea is a perennial halophyte and is tolerant to Cd. However, the mechanisms underlying this Cd tolerance are still poorly understood. In this study, morphological, physiological and biochemical responses of I. lactea to a 21 d exposure to different concentrations of Cd (0-150mgL-1) were investigated. I. lactea plants showed no toxicity symptoms except for a small reduction in growth at 100 and 150mgL-1 Cd, along with the enhancement of H2O2 and MDA content in comparison to the control. The activities of SOD and POD were significantly enhanced and Ca accumulated with increasing Cd concentrations. Moreover, most Cd was retained in roots and only a small amount was transported to the shoots with increasing external Cd concentrations. Cd content had a negative correlation with content of K, Fe, Zn, and Mn and a positive correlation with Mg content in shoots and roots, which had no influence on these contents of mineral nutrients in shoots and chlorophyll levels with the increase of Cd concentrations. The Cd translocation factors were always less than 1 and bioaccumulation factors ranged from 3.43 to 15.6 across all treatments, suggesting that I. lactea might be effectively used in phytostabilization of Cd contaminated soils. Overall, the findings suggest that I. lactea could reduce photoinhibition and oxidative damage and maintain metal ion homeostasis in plant tissue by limiting translocation of Cd from roots to shoots and enhancing induction of antioxidant enzyme activities, thereby improving its Cd tolerance.

[Dynamic changes of TGF-α and TGF-ß1 in rats with liver cirrhosis induced by multiple pathogenic factors].

OBJECTIVE: To explore the dynamic changes of transforming growth factor-α (TGF-α) and transforming growth factor-ß1 (TGF-ß1) of liver cirrhosis induced by multiple pathogenic factors in rats. METHODS: Animals in the cirrhosis group were fed a mixture of maize flour, lard, cholesterol and alcohol plus subcutaneously injection with carbon tetrachloride (CCl4), the CCl4(0.5 ml/100 g · w) was injected at the first day of experiment and the 40% CCl4oil solution (0.3 ml /100 g · w) was injected at an interval of three days. The thirty-six male SD rats were randomly divided into liver cirrhosis group of the 4th, 6th and 8 th week, and normal control group of the 4th, 6th and 8th week. The contents of alanine transferase (ALT), endotoxin, tumor necrosis factor-α (TNF-α) and homocysteine (Hcy) in plasma were evaluated. Histopathological changes of the liver were observed under microscope with the staining of HE. The expressions of TGF-α and TGF-ß1 were analyzed by the method of immunohistochemistry. RESULTS: Compared with the corresponding normal control group, the levels of ALT, endotoxin, TNF-α and Hcy in plasma were gradually significantly increased in liver cirrhosis group of the 4th, 6th and 8th week (P < 0.05); the expression of TGF-α in the liver tissues was significantly increased at the 4th week (P < 0.05); the expression of TGF-ß1 in the liver tissues was gradually significantly increased in every model group (P < 0.05). CONCLUSION: In the formation process of cirrhosis, the expression of TGF-α was increased in liver of cirrhosis group at the 4th week, and later it was suppressed; the expression of TGF-ß1 was continuously increased. The characteristic dynamic changes of TGF-α and TGF-ß1 might be related to sustained endotoxemia, the high level of TNF-α and hyperhomocysteinemia.

Effect of artesunate supplementation on bacterial translocation and dysbiosis of gut microbiota in rats with liver cirrhosis.

AIM: To evaluate the effect of artesunate (AS) supplementation on bacterial translocation (BT) and gut microbiota in a rat model of liver cirrhosis. METHODS: Fifty-four male Sprague-Dawley rats were randomly divided into a normal control group (N), a liver cirrhosis group (M) and a liver cirrhosis group intervened with AS (MA). Each group was sampled at 4, 6 and 8 wk. Liver cirrhosis was induced by injection of carbon tetrachloride (CCl4), intragastric administration of 10% ethanol, and feeding a high fat diet. Rats in the MA group were intragastrically administered with AS (25 mg/kg body weight, once daily). Injuries of the liver and intestinal mucosa were assessed by hematoxylin-eosin or Masson's trichrome staining. Liver index was calculated as a ratio of the organ weight (g) to body weight (g). The gut microbiota was examined by automated ribosomal intergenic-spacer analysis of fecal DNA. BT was assessed by standard microbiological techniques in the blood, mesenteric lymph nodes (MLNs), liver, spleen, and kidney. RESULTS: Compared to group N, the body weight was reduced significantly in groups M and MA due to the development of liver cirrhosis over the period of 8 wk. The body weight was higher in group MA than in group M. The liver indices were significantly elevated at 4, 6 and 8 wk in groups M and MA compared to group N. AS supplementation partially decreased the liver indices in group MA. Marked histopathologic changes in the liver and small intestinal mucosa in group M were observed, which were alleviated in group MA. Levels of pro-inflammatory interleukin-6 and tumor necrosis factor-α were significantly elevated at 8 wk in ileal homogenates in group M compared to group N, which were decreased after AS supplementation in group MA. The dysbiosis of gut microbiota indicated by the mean diversity (Shannon index) and mean similarity (Sorenson index) was severe as the liver cirrhosis developed, and AS supplementation had an apparent intervention effect on the dysbiosis of gut microbiota at 4 wk. The occurrence of BT was increased in the liver of group M compared to that of group N. AS supplementation reduced BT in group MA at 8 wk. BT also occurred in the MLNs, spleen, and kidney, which was reduced by AS supplementation. BT was not detected in the blood in any group. CONCLUSION: Dysbiosis of gut microbiota, injury of intestinal mucosal barrier and BT occurred as liver cirrhosis progressed, which might enhance inflammation and aggravate liver injury. AS may have other non-antimalarial effects that modulate gut microbiota, inhibit BT and alleviate inflammation, resulting in a reduction in CCl4, alcohol and high fat-caused damages to the liver and intestine.

Cloning and Transformation of EeHKT1;4 Gene from Elytrigia elongata.

The EeHKT1;4 gene was firstly cloned from Elytrigia elongata by RT-PCR technique with 1977 bp full-length cDNA encoding 1722 bp open reading frame (ORF) and 573 amino acids. The PCR fragment of EeHKT1;4 gene was inserted into the binary vector pBI121 and got the resulted expression vector, which named pBI121-35S-EeHKT1;4-Nos. The vector was further transformed into the agrobacterium EHA105, and then EeHKT1;4 gene was transferred into tobacco by the Agrobaterium- mediated genetic transformation method. The results showed that the target gene was inserted into the genomes of tobacco and expressed. Therefore, the transgenic tobacco (T0) plants overexpressing EeHKT1;4 gene were successfully obtained in this study. And EeHKT1;4 reduces Na+ concentration in the leaves of T0 plants, thereby plays a central role in protecting plant leaves from salinity stress.

[Protective effect of tanshinol on the hepatopulmonary syndrome in rat].

OBJECTIVE: To explore the mechanism of tanshinol on alleviate the inflammatory injury of lung tissue in rat hepatopulmonary syndrome (HPS). METHODS: SD rats were randomly divided into normal control group (n = 8), hepatopulmonary syndrome (HPS) group (n = 11) and tanshinol intervention group (n = 9). HE staining was used to observe the histopathology changes of pulmonary and hepatic tissues, and to count the number of macrophages in lung tissues. The activity of alanine transferase (ALT) and concentrations of endotoxin, tumor necrosis factor-a (TNF-alpha) and homocystein (Hcy) in plasma were detected. The concentrations of TNF-alpha, nitric oxide (NO) and malondialdehyde (MDA) and the activity of inducible nitric oxide synthase (iNOS) in the lung tissues were measured, respectively. RESULTS: Thickened alveolar septum and increased macrophages were observed in lungs in HPS rat. After administered with tanshinol, the pulmonary pathological changes were alleviated and the number of macrophages in lung tissue was decreased compared with HPS group. The activity of ALT and the concentrations of endotoxin, TNF-alpha and Hcy in plasma ,and TNF-alpha, iNOS, NO and MDA in lung tissue in HPS group were higher than those of normal control group; meanwhile, those tanshinol group were less those that of HPS group. CONCLUSION: Tanshinol may play an important role in delaying the development of HPS through protecting liver or directly antagonizing the effect of intestinal endotoxemia so as to alleviate the inflammatory reaction in lung tissue.