Changes of hydroxyl radical,malondialdehyde and total antioxidant capa-city in intestines after orthotopic liver autotransplantation in rats

AIM: To explore the pathological changes of small intestines after orthotopic liver autotransplantation in rats and to analyze the correlation between these changes and the levels of hydroxy radical (稯H),malondialdehyde(MDA)and total antioxidant capacity(T-AOC). METHODS: Thirty-six Sprague-Dawley rats were randomly divided into sham operation group (group S, n=6) and model group (group M). According to the period after liver reperfusion, the rats in group M were divided into 5 sub-groups: 2 h after reperfusion (group M1, n=6), 4 h after reperfusion (group M2, n=6), 8 h after reperfusion (group M3, n=6), 16 h after reperfusion (group M4, n=6), and 24 h after reperfusion (group M5, n=6). After anesthesia, the rats in group S involved laparotomy and vascular dissection without hepatic vascular exclusion and perfusion. The rats in other groups received orthotopic liver autotransplantation. The intestinal tissues starting from 5 cm to terminal ileum were removed 2 h, 4 h, 8 h, 16 h and 24 h after reperfusion. The morphological changes of intestinal epithelial basement membrane were observed under optical microscope. The levels of 稯H, MDA and T-AOC were detected. RESULTS: (1) In model groups, the morphological damages in the intestines were significant compared to group S, especially 8 h after reperfusion. The intestines showed massive epithelial lifting down the sides of villi and a few tips being denuded. The repair of pathological damage in the intestines 24 h after reperfusion was observed. (2) Compared to group S, the levels of 稯H in the intestines significantly increased in group M2, M3 and M4 (P<0.05). The levels of MDA in the intestines significantly increased in group M1, M2 and M3 (P<0.05). The levels of T-AOC significantly decreased in group M1, M2, M3 and M4 (P<0.05). CONCLUSION: Orthotopic liver autotransplantation increases the levels of 稯H and MDA, diminishes T-AOC and induces reversible pathological changes in intestines.     

Effects of fructose sodium diphosphate on expression of CHOP and JNK in endoplasmic reticulum stress and islet apoptosis in rats with type 2 diabetes

AIM: To study the effects of fructose sodium diphosphate (FDP) on the expression of CHOP and c-Jun N-terminal binase(JNK) in endoplasmic reticulum stress and islet apoptosis in the rats with type 2 diabetes mellitus (T2DM). METHODS: T2DM model was established in male Wistar rats by feeding of high lipid diet and injection of streptozotocin. The rats were divided into 4 groups (n=8):normal control group, T2DM model group, T2DM+low-dose FDP (2 mL穔g^-1穌^-1, ip) group and T2DM+high-dose FDP (5 mL穔g^-1穌^-1, ip) group. The rats in the treatment groups received FDP for 8 weeks. The levels of fasting blood glucose (FBG), fasting serum insulin (FINS) and insulin sensitivity index (ISI) were measured. TUNEL was used to detect the islet apoptosis. The protein levels of CHOP and JNK were determined by the method of immunohistochemistry. RESULTS: (1) Compared with normal control group, FBG, FINS, the expression of CHOP and JNK, and apoptosis in T2DM model group were significantly increased (P<0.01). The level of ISI was significantly decreased. (2) Compared with T2DM model group, the levels of FBG and FINS, the expression of CHOP and JNK, and apoptosis in high-dose FDP group were significantly decreased. The level of ISI was significantly increased (P<0.01). However, the level of FBG, the expression of CHOP and JNK, and apoptosis in low-dose FDP group were significantly decreased. Compared with low-dose FDP group, the levels of FBG and FINS, the expression of CHOP and JNK, and apoptosis in high-dose FDP group were significantly decreased. The level of ISI was significantly increased (P<0.01 or P<0.05). CONCLUSION: FDP may prevent islet cells from apoptosis in T2DM rats by decreasing the expression of CHOP and JNK.     

Artesunate negatively controls expression of cyclin D1 and activity of AP-1 by inhibiting the activation of ERK1/2 protein in HSC-T6 cells

AIM: To investigate the effects of artesunate(Art) on the expression of ERK1/2, AP-1 and cyclin D1 in rat hepatic stellate cells (HSCs), and to elucidate the molecular mechanism of Art against hepatic fibrosis. METHODS: HSC-T6 cells were treated with platelet-derived growth factor BB(PDGF-BB) to induce cell proliferation. The cells were divided into control group, PDGF-BB group, PDGF-BB+Art groups (with 6.25 mg稬^-1, 25 mg稬^-1or 50 mg稬^-1 of Art) and PDGF-BB+PD98059 group. The level of collagen type I in the supernatant was detected by enzyme-linked immunosorbent assay (ELISA). The mRNA expression levels of ERK1/2 and cyclin D1 were measured by RT-PCR. The protein levels of p-ERK1/2 and cyclin D1 in HSC-T6 cells were detected by Western blotting. The activity of AP-1 was analyzed by electrophoretic mobility shift assay. RESULTS: The concentration of collagen type I was significantly higher in PDGF-BB group than that in control group (P<0.05), and decreased in PDGF-BB+Art group and PDGF-BB+PD98059 group in comparison with that in PDGF-BB group (P<0.05, P<0.01). The protein level of ERK1/2 in PDGF-BB+Art group (50 mg稬^-1) was lower than that in PDGF-BB group (P<0.05), and was even lower in PDGF-BB+PD98059 group (P<0.01). The mRNA expression of cyclin D1 in PDGF-BB+Art groups (25 mg稬^-1and 50 mg稬^-1) and PDGF-BB+PD98059 group were significantly lower than that in PDGF-BB group (P<0.05). The protein levels of p-ERK1/2 and cyclinD1 were the highest in PDGF-BB group, and significantly lower in PDGF-BB+Art groups (6.25 mg稬^-1, 25 mg稬^-1 and 50 mg稬^-1) and PDGF-BB+PD98059 group (P<0.05, P<0.01). The AP-1 binding activity in HSC-T6 cells was down-regulated by Art. CONCLUSION: Artesunate inhibits the proliferation of HSC-T6 cells in vitro by inhibiting the activation of ERK1/2, thus down-regulating the activity of AP-1 and expression of cyclin D1.     

Research and utilization progress in banana germplasm resources in China北大核心CSCD

Banana is one of the main fruit crops and important food crops in the world, and it is also an important economic fruit in southern China. China is the border area of the origin of modern bananas, and one of the secondary origin centers as well. China has a history of banana cultivation for more than 2000 years and is the second largest country in banana production and consumption. Banana producing areas in China are mainly concentrated in Guangdong, Guangxi, Hainan, Yunnan, Fujian and Taiwan, with a small amount of cultivation in the south of Sichuan, Guizhou and Tibet. Most cultivated bananas are evolved from two wild species, Musa acuminate and Musa balbisiana, and their interspecific hybridization. The genome of Musa acuminata is called“genome A”, while the genome of Musa balbisiana is called“genome B”. According to the classification value of characteristics, banana cultivars can be divided into genotypes such as AA, AAA, AB, AAB, ABB, AAAA, AAAB, AABB, BB and BBB. Bananas cultivated in China are simply divided into four categories: Cavendish (AAA), Pisang Awak (ABB), Silk (AAB) and Dajiao (ABB). Cavendish banana is planted mostly in China (more than 80%), followed by Pisang Awak (more than 10%). Notably, in China, few people plant and consume Plantain (AAB), which is an important staple food in some area. Banana breeding mainly includes introduction (like Brazil and Williams banana), vegetative line selection (like GCTCV bananas), artificial mutation breeding (like Jiali banana), cross breeding (like Fenza No. 1 and Zhongjiao No. 9 banana), chromosome ploidy breeding, transgenic breeding and gene editing breeding. The introduction method is simple and direct. Our group took the lead in establishing the National Banana Germplasm Resource Garden in 1989. In the future, we should introduce not only high-quality varieties, but also multifunctional and diverse banana varieties to enrich China’s banana market. After introduction, people often get better lines that adapt to Chinese geographical and climatic conditions and planting habits, and then popularize them. Mutation breeding is easy, but the ideal excellent lines can only be obtained through a large number of screening and evaluation. The female flowers of some bananas, like Dajiao and Pisang Awak, have strong fertility, so they are often used as female parents to cross with wild bananas or cultivated varieties with certain fertility. Although sexual hybridization of banana needs a long period and is easy to fail, this method can often create new germplasm with diverse genetic background and relatively controllable traits, which is the most potential and promising method in traditional banana breeding at present. In recent years, researchers in China have created many new hybrid banana germplasm, and it can be predicted that a large number of new hybrid banana varieties will emerge in China in the near future. Banana transgenic and gene editing breeding have strong pertinence. China has made good achievements in the fields of banana transgenic and gene editing. However, as in many other parts of the world, these methods cannot be applied to business at present. At last, other breeding methods like somatic hybridization, rapid breeding and molecular-assisted breeding are rarely used at present. Banana Fusarium wilt and other diseases seriously threaten banana industry in China. At the same time, frequent typhoons and floods, severe frost and poor soil in the main banana producing areas in China also limit the further development of banana industry. Breeding new banana varieties with high yield, high quality and high stress resistance and adaptability is the key to break the bottleneck of banana industry development in China, and it is also a challenge for banana breeders in China. In addition, it is also an important direction to cultivate bananas with high nutrition and health care function, which are suitable for industrial processing or feed. During the last decades, China has made great achievements in banana breeding, but there are still many problems. First of all, banana biodiversity is relatively lacking, with few wild banana resources. Moreover, the careful evaluation of banana germplasm resources is not enough, limiting the utilization of them. Secondly, the main banana varieties in China were bred by introduction and mutation breeding, and only a few were bred by hybridization or other means. Moreover, due to many reasons, there is a lack of varieties with good comprehensive characteristics. Finally, it is difficult to study genes in banana through the forward or reverse genetic means, limiting the molecular research on banana. In the future, we should: (1) Continue to strengthen the collection, evaluation and utilization of global banana germplasm resources, and especially promote banana cross breeding vigorously; (2) Pay attention to the basic research on banana, dig out the key genes related to important economic traits, and analyze their regulatory networks, so as to lay the foundation for creating new banana varieties without transgene through gene editing technology in the future; (3) Continuously develop and upgrade new breeding techniques, promote the integration of various means, and breed efficiently and scientificly; (4) Breed new varieties that are resistant to various diseases and have good comprehensive properties, so as to win the banana defense war. In a word, we have summarized the research results of banana breeding in China in recent years, discussed the methods of banana breeding, the direction of new variety breeding and the main problems, in order to provide reference for banana breeding in China. © 2023 Journal of Fruit Science. All rights reserved.     

Retinoic acid inhibits renal interstitial myofibroblast proliferation in a rat unilateral ureteral obstruction model

AIM: To investigate the effect of retinoic acid on proliferation of renal interstitial myofibroblasts in a rat model of the left unilateral ureteal obstruction (UUO). METHODS: UUO model was established by unilateral ligation of ureter in 36 SD rats. Rats were divided into 2 groups: Retinoic acid-treated group and control group, each with 18 rats. UUO rats were treated with either daily subcutaneous injection of 10 mg/kg body weight of all trans-retinoic acid or vehicle alone two days before the operation until being sacrificed. Groups of 6 rats were killed on day 3, 7 and 12 after ligation of the left ureter. The percentage of renal tubular lesion, interstitial fibrosis score, the number of interstitial myofibroblasts, the number of proliferating myofibroblasts and the expression of TGFβ-1 mRNA were determined. RESULTS: There were significant accumulation and local proliferation of myofibroblasts in the interstitium of the UUO rats. On day 7 of the UUO model, the percentage of tubular lesions and interstitial fibrosis score were significantly lower in the retinoic acid-treated group than those in control group[(15.9±2.0)%vs(27.3±2.2)%和(0.47±0.12)vs(1.65±0.18),P<0.01]. The numbers of interstitial myofibroblasts and proliferating myofibroblasts in the retinoic acid-treated group were significantly lower than those in the control group[(12.2±2.2)cells/HPF vs(29.5±1.8)cells/HPF和(1.4±0.6)cells/HPF vs(4.3±0.8)cells/HPF,P<0.01]. Furthermore, the expression of TGFβ-1 mRNA was significantly lower in the retinoic acid-treated group than that of the control group (P<0.01). CONCLUSION: Retinoic acid suppresses interstitial fibrosis in a rat UUO model by inhibiting the accumulation and local proliferation of myofibroblasts in the renal interstitium.     

整合农艺性状和分子标记数据构建新疆野苹果核心种质

AIM: To explore the effect of traditional Chinese medicine Qiliqiangxin on cardiomyocyte apoptosis after myocardial infarction (MI) in a rat model. METHODS: MI was induced in rats by ligation of the anterior descending coronary artery. The survivors were randomly divided into 3 groups: sham operation group, MI group and Qiliqiangxin treatment group (4 g穔g^-1穌^-1). After 28 days, the infarction size was measured. Apoptotic index (AI) was determined by TUNEL. The expression of Fas was detected by the method of immunohistochemistry in non-infarcted zones (NIZ), and the expression of xanthine oxidase (XO) and caspase-3 in myocardial tissue from NIZ was detected by Western blotting. In addition, XO activity, and O₂ ^-? and OH? scavenging activity of myocardial tissues in the NIZ were measured by colorimetry. RESULTS: Compared with MI group, AI and the expression of Fas and caspase-3 in the NIZ were significantly depressed in Qiliqiangxin treatment group. Moreover, the activity of XO was significantly decreased while O₂ ^-? and OH穝cavenging activity was significantly increased in Qiliqiangxin treatment group. Ventricular remodeling was attenuated. No significant difference in infarct size and XO expression level between Qiliqiangxin treatment group and MI group was observed. CONCLUSION: Qiliqiangxin may inhibit apoptosis of cardiomyocytes in the NIZ of rats by reducing reactive oxygen species and depressing the expression of Fas and caspase-3.     

Protective effect of pyrrolidine dithiocarbamate on kidneys in type 2 diabetic rats

AIM: To investigate the protective effect of pyrrolidine dithiocarbamate (PDTC) on the kidneys in type 2 diabetic rats. METHODS: High-fat diet and a small dose (27 mg/kg) of streptozotocin-induced diabetic rats were treated with or without PDTC (50 mg穔g^-1穌^-1, ip) for 1 week, and age-matched nondiabetic animals were also used for comparison. The concentration of malondialdehyde (MDA)and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined by commercial kit. The ratio of urine microalbumin/creatinine was measured by an automatic biochemical analyzer. The morphological changes of renal glomerulus were observed by HE/Masson staining and transmission electron microscopy. The expression of inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) in the renal tissues was examined by the method of immunohistochemistry. RESULTS: PDTC-treated rats had lower blood glucose level and urine microalbumin/creatinine ratio than those in untreated diabetic rats. The levels of tissue MDA in diabetic rats were significantly higher, and the activity of SOD and GSH-Px was lower than those in normal control rats (P<0.05). The renal damage in diabetic rats was significantly improved after PDTC treatment. PDTC administration markedly attenuated the expression of iNOS and the production of NT in renal glomerulus and tubule in diabetic rats. CONCLUSION: PDTC not only reduces blood glucose level, but also protects the diabetic rats from diabetic nephropathy by diminishing the expression of iNOS and the production of NT.     

Classification of Morchella species from Yunnan and Zhejiang Provinces Based on rDNA ITS Sequences

Fourteen Morchella samples (eleven from Yunnan and three from Zhejiang Provinces) were selected on the basis of differences in fruit body morphology. Ribosomal DNA internal transcribed spacers (ITS) were amplified in each case using the universal primer pair, ITS-1 and ITS-4, and the amplification products were purified and sequenced. Comparisons with sequence data in GenBank revealed that the 11 Morchella isolates collected from Yunnan belonged to four species: Morchella elata, Morchella conica, Morchella crassipes and Morchella costata. The three isolates collected from Zhejiang Province (M12, M13 and M14) were designated as unknown Morchella species. When Verpa conica (AJ544206) (from the genus Verpa belonging to the same family as Morchella) was taken as the outgroup, the 14 isolates formed three groups, M. elata, M. costata (Group 1); Morchella esculenta, M. conica (Group 2); and M. crassipes, M12, M13 and M14 (Group 3).     

SRAP、ISSR和RAPD分子标记技术在银耳菌株鉴别上的应用

Three types of molecular markers (SRAP, ISSR and RAPD) were used to identify four Tremella fuciformis strains, T6 (white), T7 (white), T8 (yellow) and T9 (light yellow). Twelve SRAP primer pairs, ten ISSR primers and eight RAPD primers were screened, and identification data obtained using the three molecular markers were consistent in that the four T. fuciformis strains were divided into three groups with T7 and T9 clustered together in a single group. Each RAPD primer generated a higher average number of polymorphic bands than either the SRAP or ISSR primers, and the average similarity between the four strains was 81.34%. SRAP markers reflected more genetic information compared with the two other markers, and the average similarity was 68.98%. Genetic information reflected by ISSR markers was intermediate between SRAP and RAPD, and the average similarity was 77.48%.     

Risk assessment of dietary intake of pesticide residues in kiwifruit北大核心CSCD

【Obiective】Risk assessment of dietary exposure to pesticide residues in kiwifruit and quantifiction of the dietary risk levels of commonly used pesticides provide references for safe production and guidance for consumption of the fruit, food safety supervision, and revision of the Maximum Residue Limits (MRLs) of kiwifruit.【Methods】Based on detection of the residues of 66 pesticides in 61 kiwifruit samples from a major producing area, chronic dietary intake risk (%ADI) and acute dietary intake risk (%ARfD) of pesticide residues in these samples were assessed. Based on the veterinary drug residue risk ranking matrix constructed by the British Veterinary Drug Residues Committee, the risk of th epesticides and samples was ranked by integrating kiwifruit consumption and pesticide toxicity, frequency of use and residue level, and maximum residue limit estimates (eMRL) were calculated using allowable daily intake (ADI) values, large portion consumed (LP), and body weight (bw). The study will provide a reference for the regulation of the maximum residue limit (MRL) for the corresponding pesticides.【Results】(1)Among the 62 pesticides, a total of 21 pesticides were detected, and they were low-toxic pesticides except for chlorpyrifos, deltamethrin, cypermethrin and cyhalothrin, which were moderately toxic; (2) Using the pesticide toxicology data, acceptable daily intake (ADI) and acute reference does (ARfD), residual data and kiwifruit consumption data, the risk assessment of the 21 pestcides detected showed that the chronic dietary intake (%ADI) of each pesticide inkiwifruitranged from 0.000 01% to 0.016 04%. All the 21 pesticides detected but acetamiprid and chlorpyrifos without ARfD information had an acute dietary intake (%ARfD) ranging from 0.01% to 26.20%. The acute dietary intake risk difference between different pesticides was significantly. (3) According to the residual risk score, the 21 pesticides detected were medium- to low-risk pesticides. The risk scores for deltamethrin and chlorpyrifos were 16.5 and 16.1 ie(15≤S<20), respectively, which were in the medium-risk range. The risk scores of cypermethrin, pyrimidine, buprofezin, cyhalothrin and difenoconazole were between 12.1 and 12.4, and the risk scores of 14 pesticides including procymidone and chlorpyrifos ranged from 8.0 to 9.3 (S< 15). All of them were low-risk pesticides. Among the 61 kiwifruit samples, 45.9% of the samples were in a very low risk area with a pesticide residue risk index (RI) below 5; 34.4% of the samples were in a low risk range with a pesticide residue RI between 5 and 10; and 18.0% of the samples were in a medium risk range with a pesticide residue RI of 10 and 15; (4) At present, there were few standard pesticides in kiwifruit. Among the 21 pesticides detected, only carbendazim, acetamiprid, chlorpyrifos, deltamethrin, and cyhalothrin had maximum residue limit (MRL) in kiwifruit or berries and other small fruits in GB 2763—2016, while 76.2% the pesticides had not a limit value. Compared with eMRL, the MRL values of the five pesticides was a more strict parameter related to limitation of quantities. For example, the eMRL of carbendazim was 6.6 times that of MRL; the eMRL of acetamiprid was 3.8 times that of MRL; the eMRL of cyhalothrin was 10.9 times that of MRL; the eMRL of deltamethrin 21.9 times that of MRL; and the eMRL of chlorfenuron was 153 times that of MRL. Among the 21 pesticides detected, carbendazim, acetamiprid, cyhalothrin, deltamethrin and chlorpyrifos had MRLs, and azoxystrobin, chlorfenapyr, malathion, and procymidone had no necessecity to formulate MRL. 12 pesticides including thiamethoxam, imidacloprid, thiophanate- methyl, tebuconazole, propiconazole, prochloraz, difenoconazole, buprofezin, trifloxystrobin, chlorpyrifos, cypermethrin and chlorothalonil had no MRLs.【Conclusion】The pesticides detected were all middle- risk or low- risk pesticides, and the acute and chronic dietary risks of the 21 pesticides were acceptable. At the same time, 98.4% of the 61 samples were at medium, low or very low risk. Therefore, the kiwifruit in the major producing area was relatively safe. It was recommended to develope the MRLs of 12 pesticides including thiamethoxam and imidacloprid for in kiwifruit. © 2019 Journal of Fruit Science