Salicylic acid-primed defence response in octoploid strawberry 'Benihoppe' leaves induces resistance against Podosphaera aphanis through enhanced accumulation of proanthocyanidins and upregulation of pathogenesis-related genes.

BACKGROUND: Podosphaera aphanis, a predominately biotrophic fungal pathogen, causes significant yield losses of strawberry. China is the largest strawberry producer in the world, and selecting for powdery mildew-resistant cultivars is desirable. However, the resistance mechanism against P. aphanis in the octoploid strawberry remains unclear. RESULTS: To understand possible mechanisms of disease resistance, we inoculated strawberry leaves with P. aphanis, and examined the expression profiles of candidate genes and the biochemical phenotypes in strawberry leaves of two groups. The unigenes obtained from ddH2O- and SA-pretreated leaves resulted in a total of 48,020 and 45,896 genes, respectively. KEGG enrichment showed that phenylpropanoid biosynthesis and plant hormone signal transduction pathways were enriched to a noticeable extent. DEG analysis showed that key TFs genes associated with the SA signaling pathway could play important role in the strawberry-P. aphanis interaction. In particular, FaWRKY70, FaJAZ1 and FaMYC2-like, involved in regulating the antagonistic effect of SA and JA signaling pathway, leading to increased expression of SA-responsive genes (in particular PR1, PR2, PR3, and PR5) compared to a decline in expression of JA-responsive genes (FaJAR1, FaAOS, and FaLOX2). Furthermore, SA pretreatment induced accumulation of PAs by activating the MBW complex and inhibit powdery mildew growth. CONCLUSIONS: This study describes the role of the proanthocyanidins (PAs), pathogenesis-related (PR) genes, SA, and transcription factors in regulatory model against P. aphanis, which coincided with an early activation of defense, leading to the accumulation of PAs and the PR proteins.

Distinct quasispecies characteristics and positive selection within precore/core gene in hepatitis B virus HBV associated acute-on-chronic liver failure.

BACKGROUND AND AIM: The cause of hepatitis B virus associated acute-on-chronic liver failure (ACLF) remains unclear. Quasispecies can contribute to virus persistence and pathogenesis. We used a bioinformatics-based molecular evolution approach to compare quasispecies characteristics and positive selection sites within HBV precore/core gene between ACLF and chronic hepatitis B (CHB) patients. METHODS: HBV precore/core gene were amplified from 11 ACLF and 10 CHB patients harboring HBV genotype B; following DNA cloning and sequencing quasispecies complexity, diversity, and positive selection sites within the precore/core gene were determined by bioinformatics analysis, and compared between the patient groups. RESULTS: Both quasispecies complexity (P=0.022 at nucleotide level and 0.008 at amino acid level) and diversity (P<0.05) were found to be significantly greater in ACLF than in CHB. The frequency of G1896/A mutation in ACLF (175/298 clones, 58.7%) was also significantly higher than in CHB (100/230 clones, 43.5%) (P=0.0005). Moreover, analysis of positive selection revealed that significantly more patients with such sites were present in ACLF than in CHB (8/11 VS 2/10, P=0.03); the majority of these positive selection sites lay within HLA-restricted epitopes. CONCLUSIONS: The ACLF patients showed distinct quasispecies characteristics with higher complexity and diversity within the HBV precore/core gene. The increased HBV quasispecies complexity and diversity, together with a distinct set of positive selection sites, is likely associated with the development of ACLF.

[The impact of early rapid virological response on the outcomes of hepatitis B associated acute on chronic liver failure during antiviral treatment].

OBJECTIVE: To investigate the impact of early rapid virological response on the outcomes of hepatitis B associated acute on chronic liver failure during antiviral treatment. METHODS: 106 acute on chronic liver failure patients in our hospital from January 2008 to July 2010 were enrolled in present study retrospectively. Besides internal medicine therapy, all patients received lamivudine (100 mg/d) or entecavir (0.5 mg/d) treatment. The profile of liver biochemistry, prothrombin time activity and viral load were detected at baseline and week 4, respectively. The patients were divided into HBV DNA negative group and HBV DNA positive group according to the viral load at week 4. The clinical features and treatment outcomes were compared between groups. Frequency variables were compared by x2 test or Fisher's exact test. Continuous variables were compared using independent samples T-test. The factors that impact on the treatment outcomes were determined using stepwise multivariate logistic regression analysis. RESULTS: At the week 4, the TBil and PTA in HBV DNA positive group [(261.6+/-205.6)mumol/L and 44.7%+/-19.7%, respectively] were significantly different from those in HBV DNA negative group [(160.1+/-173.4) mumol/L and 56.8%+/-23.1%, respectively] ( t = 2.190 and -2.077, respectively, P less than 0.05). The non-effective rate of HBVDNA positive group (50%, 9/18) was significantly higher than that of HBV DNA negative group (14.8%, 13/88) (x2 = 9.235, P less than 0.01). By using stepwise multivariate logistic regression analysis, the disease stage and HBV DNA undetectable at week 4 were the independent factor. The OR values of disease stage and HBV DNA undetectable were 6.559 and 0.209, respectively, and 95% CI was 2.316~18.576 and 0.058~0.747, respectively. CONCLUSION: The rapid suppression of viral load by nucleotide analogue may improve the efficacy of hepatitis B associated acute on chronic liver failure treatment. The early rapid virological response within first 4 weeks may contribute to the prediction of the treatment outcomes.

Effects of ipriflavone on postmenopausal syndrome and osteoporosis.

OBJECTIVE: To investigate the therapeutic effects of ipriflavone on postmenopausal syndrome and osteoporosis in women. METHODS: A randomized and double-blind study was conducted. Sixty postmenopausal women with osteoporosis were chosen and they were randomly divided into three groups: Treatment group I was given oral compound calcium acid chelate and Vitamin AD guttate; treatment group II was given oral compound calcium acid chelate, Vitamin AD guttate and ipriflavone; Control group was given placebo and compound calcium acid chelate. The postmenopausal syndrome, bone mineral density (BMD), and bone biochemical markers were assessed 6 and 12 months after the treatment. RESULTS: In treatment group II, hot flush and ostalgia syndromes were dramatically relieved, BMD and serum calcium level increased markedly and alkaline phosphatase, parathyroid hormone and tartrate-resistant acid phosphatase decreased markedly, comparing with treatment group I and control group (p < 0.05). CONCLUSION: Ipriflavone could inhibit bone resorption and promote bone formation. It is an effective drug for the prevention and treatment to menopausal syndrome and osteoporosis. Ipriflavone could be used as a supplement to estrogen replacement treatment.

Proteomic technique used in studying ovule development of Chinese pine (Pinus tabulaeformis Carr.).

Chinese pine (Pinus tabulaeformis Carr.) is one of the most important afforestation and ornamental species in China. Ovule abortion is a serious problem influencing the output of seeds and reproduction of Chinese pine. So it is of much significance to study the mechanisms of ovule development and abortion of Chinese pine. By combining two-dimensional gel electrophoresis (2-DE) and mass spectrometry analysis, the patterns of gene expression in a specific tissue at a specific stage can be displayed and characterized. This study acquired an appropriate protein extraction method from ovules of Chinese pine and optimized the conditions for protein identification by mass spectrometry.

Electroacupuncture Ameliorates Learning and Memory and Improves Synaptic Plasticity via Activation of the PKA/CREB Signaling Pathway in Cerebral Hypoperfusion.

Electroacupuncture (EA) has shown protective effects on cognitive decline. However, the underlying molecular mechanisms are ill-understood. The present study was undertaken to determine whether the cognitive function was ameliorated in cerebral hypoperfusion rats following EA and to investigate the role of PKA/CREB pathway. We used a rat 2-vessel occlusion (2VO) model and delivered EA at Baihui (GV20) and Dazhui (GV14) acupoints. Morris water maze (MWM) task, electrophysiological recording, Golgi silver stain, Nissl stain, Western blot, and real-time PCR were employed. EA significantly (1) ameliorated the spatial learning and memory deficits, (2) alleviated long-term potentiation (LTP) impairment and the reduction of dendritic spine density, (3) suppressed the decline of phospho-CREB (pCREB) protein, brain-derived neurotrophic factor (BDNF) protein, and microRNA132 (miR132), and (4) reduced the increase of p250GAP protein of 2VO rats. These changes were partially blocked by a selective protein kinase A (PKA) inhibitor, N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide (H89), suggesting that the PKA/CREB pathway is potentially involved in the effects of EA. Moreover, any significant damage to the pyramidal cell layer of CA1 subregion was absent. These results demonstrated that EA could ameliorate learning and memory deficits and alleviate hippocampal synaptic plasticity impairment of cerebral hypoperfusion rats, potentially mediated by PKA/CREB signaling pathway.

Effect of vector-expressed shRNAs on hTERT expression.

AIM: To study the effect of short hairpin RNAs (shRNAs) expressed from DNA vector on hTERT expression. METHODS: Oligonucleotides coding for four shRNAs against hTERT were cloned into a mammalian shRNA expression vector pUC18U6 to form pUC18U6ht1-4, which were then introduced into HepG2 cells by using liposome-mediated transfection. HepG2 cells transfected by pUC18U6 and pUC18U6GFPsir, which expressed shRNA against green fluorescent protein (GFP), were used as controls. hTERT mRNA in the transfected cells were quantified by using real-time fluorescent RT-PCR. RESULTS: Among the four shRNAs against hTERT, two decreased the hTERT mRNA level. Compared with the controls, pUC18U6ht which expressed the two shRNAs reduced hTERT mRNA by 39% and 49% (P<0.05). CONCLUSION: hTERT expression is inhibited by the shRNAs expressed from the DNA vector.

Repetitive magnetic stimulation promotes neural stem cells proliferation by upregulating MiR-106b in vitro.

Neural stem cells (NSCs) proliferation can be influenced by repetitive transcranial magnetic stimulation (rTMS) in vivo via microRNA-106b-25 cluster, but the underlying mechanisms are poorly understood. This study investigated the involvement of microRNA-106b-25 cluster in the proliferation of NSCs after repetitive magnetic stimulation (rMS) in vitro. NSCs were stimulated by rMS (200/400/600/800/1000 pulses per day, with 10 Hz frequency and 50% maximum machine output) over a 3-day period. NSCs proliferation was detected by using ki-67 and EdU staining. Ki-67, p21, p57, cyclinD1, cyclinE, cyclinA, cdk2, cdk4 proteins and miR-106b, miR-93, miR-25 mRNAs were detected by Western blotting and qRT-PCR, respectively. The results showed that rMS could promote NSCs proliferation in a dose-dependent manner. The proportions of ki-67+ and Edu+ cells in 1000 pulses group were 20.65% and 4.00%, respectively, significantly higher than those in control group (9.25%, 2.05%). The expression levels of miR-106b and miR-93 were significantly upregulated in 600-1000 pulses groups compared with control group (P<0.05 or 0.01 for all). The expression levels of p21 protein were decreased significantly in 800/1000 pulses groups, and those of cyclinD1, cyclinA, cyclinE, cdk2 and cdk4 were obviously increased after rMS as compared with control group (P<0.05 or 0.01 for all). In conclusion, our findings suggested that rMS enhances the NSCs proliferation in vitro in a dose-dependent manner and miR-106b/p21/cdks/cyclins pathway was involved in the process.