Hippocampal ornithine decarboxylase/spermidine pathway mediates H2S-alleviated cognitive impairment in diabetic rats: Involving enhancment of hippocampal autophagic flux.

INTRODUCTION: We have previously demonstrated the antagonistic role of hydrogen sulfide (H2S) in the cognitive dysfunction of streptozotocin (STZ)-induced diabetic rats. It has been confirmed that the impaired hippocampal autophagic flux has a key role in the pathogenesis of cognitive impairment and that ornithine decarboxylase (ODC)/spermidine (Spd) pathway plays an important role in the formation of memory by promoting autophagic flux. OBJECTIVES: To investigate the roles of hippocampal ODC/Spd pathway and autophagic flux in H2S-attenuated cognitive impairment in STZ-induced diabetic rats. METHODS: Cognitive function is judged by the novel objective recognition task (NOR), the Y-maze, and the Morris water maze (MWM) tests. The ODC/Spd pathway in hippocampus was evaluated using the expression of ODC detected by western blot and the level of Spd assayed by GC-MS. Autophagic flux was assessed using the expressions of Beclin-1, LC3II/I, and P62 detected by western blot, and the number of autophagosomes observed by transmission electron microscope. RESULTS: Sodium hydrosulfide (NaHS, a donor of H2S) markedly improved the autophagic flux in the hippocampus of STZ-exposed rats, as evidenced by a decrease in the number of autophagosomes as wells as downregulations in the expressions of LC3-II, Beclin-1, and P62 in the hippocampus of cotreatment with NaHS and STZ rats. NaHS also up-regulated the expression of ODC and the level of Spd in the hippocampus of STZ-induced diabetic rats. Furthermore, inhibited hippocampal ODC/Spd pathway by difluoromethylornithine (DFMO) markedly reversed the protections of NaHS against the hippocampal autophagic flux impairment as well as the cognitive dysfunction in STZ-exposed rats. CONCLUSION: These findings indicated that improving hippocampal autophagic flux plays a key role in H2S-attenuated cognitive impairment in STZ-induced diabetic rats, as results of up-regulating hippocampal ODC/Spd pathway.

Combining triptolide with ABT-199 is effective against acute myeloid leukemia through reciprocal regulation of Bcl-2 family proteins and activation of the intrinsic apoptotic pathway.

Bcl-2 inhibitors display an effective activity in acute myeloid leukemia (AML), but its clinical efficacy as a monotherapy was limited in part owing to failure to target other antiapoptotic Bcl-2 family proteins, such as Mcl-1. In this context, the combination strategy may be a promising approach to overcome this barrier. Here, we report the preclinical efficacy of a novel strategy combining ABT-199 with triptolide (TPL), a natural product extracted from a traditional Chinese medicine, in AML. Combination treatment exhibited markedly increased cytotoxicity in leukemic cells irrespective of p53 status while largely sparing normal cells of the hematopoietic lineage. Moreover, co-administration of ABT-199 with TPL dramatically suppressed leukemia progression as well as prolonged animal survival in a xenograft AML model. The potentiated effect of ABT-199 and TPL against AML was associated with activation of the mitochondrum-related intrinsic apoptotic pathway through a mechanism reciprocally modulating Bcl-2 family proteins. In this case, TPL not only downregulated Mcl-1 but also upregulated proapoptotic BH3-only proteins, thereby overcoming the resistance toward ABT-199. Conversely, ABT-199 abrogated Bcl-2-mediated cytoprotection against TPL. Together, these findings suggest that the regimen combining TPL and ABT-199 might be active against AML by inducing robust apoptosis through reciprocal regulation of anti- and proapoptotic Bcl-2 family proteins, therefore providing a strong rationale for the clinical investigation of this combination regimen for the treatment of AML.

microRNA-186 inhibition of PI3K-AKT pathway via SPP1 inhibits chondrocyte apoptosis in mice with osteoarthritis.

Chondrocyte apoptosis has been implicated as a major pathological osteoarthritis (OA) change in humans and experimental animals. We evaluate the ability of miR-186 on chondrocyte apoptosis and proliferation in OA and elucidate the underlying mechanism concerning the regulation of miR-186 in OA. Gene expression microarray analysis was performed to screen differentially expressed messenger RNAs (mRNAs) in OA. To validate the effect of miR-186 on chondrocyte apoptosis, we upregulated or downregulated endogenous miR-186 using mimics or inhibitors. Next, to better understand the regulatory mechanism for miR-186 governing SPP1, we suppressed the endogenous expression of SPP1 by small interfering RNA (siRNA) against SPP1 in chondrocytes. We identified SPP1 is highly expressed in OA according to an mRNA microarray data set GSE82107. After intra-articular injection of papain into mice, the miR-186 is downregulated while the SPP1 is reciprocal, with dysregulated PI3K-AKT pathway in OA cartilages. Intriguingly, miR-186 was shown to increase chondrocyte survival, facilitate cell cycle entry in OA chondrocytes, and inhibit chondrocyte apoptosis in vitro by modulation of pro- and antiapoptotic factors. The determination of luciferase activity suggested that miR-186 negatively targets SPP1. Furthermore, we found that the effect of miR-186 suppression on OA chondrocytes was lost when SPP1 was suppressed by siRNA, suggesting that miR-186 affected chondrocytes by targeting and depleting SPP1, a regulator of PI3K-AKT pathway. Our findings reveal a novel mechanism by which miR-186 inhibits chondrocyte apoptosis in OA by interacting with SPP1 and regulating PI3K-AKT pathway. Restoring miR-186 might be a future therapeutic strategy for OA.

Structural revision of methyl tortuoate D, a bis-cembranoid from Hainan Sarcophyton tortuosum and its absolute stereochemistry.

Methyl tortuoate D (1), together with five other known related bis-cembranoids, was isolated from Hainan soft coral Sarcophyton tortuosum. The structure of methyl tortuoate D (1a), firstly isolated and reported by Li et al. from the title organism, was corrected as 1 by an extensive analysis of its one-dimensional and two-dimensional nuclear magnetic resonance data and by comparison with those reported in the literature. In addition, lobophytone K (1b), recently isolated from Hainan soft coral Lobophytum pauciflorum by Lin et al., was proved to be the same compound as 1 and 1a. The absolute configuration of 1 was determined by comparing its electronic circular dichroism curve with that of co-occurring ximaolide A (2).

[Association of interleukin 28B polymorphisms with response to pegylatedinterferon plus ribavirin therapy for chronic hepatitis C].

OBJECTIVE: To investigate the characteristics of gene polymorphisms at rs12979860 of interleukin 28B (IL28B) and explore the relationships between the genetic polymorphisms and the antiviral therapy efficiency for chronic hepatitis C patients in the Sichuan region of China. METHODS: Data from 56 patients treated for 48 weeks with PEG-IFN alpha-2a plus weight-based Ribavirin (RBV), which were followed for 24 weeks after the end of treatment, were analyzed. And the IL28B rs12979860 genotype was detected by polymerase chain reaction-restriction techniques (PCR) and sequencing analysis. RESULTS: Two genotypes, CC (76.8%) and CT (23.2%), were identified in the study. There are no significant correlation in sex, age, body weight, routes of infection, baseline ALT value, baseline viral load and hepatitis C viral (HCV) genotype between the patients with CC genotype and CT genotype (P>0.05). PEG-IFN alpha-2a plus RBV showed a conspicuous therapeutic effect in patients of the Sichuan region of China, and the rate of sustained virological response (SVR) was 82.1% (46/56). The higher rates of SVR were observed in patients with IL28B genotype CC than genotype CT (90.7% versus 53.8%, P=0.009). Statistically higher proportion of SVR wasn't observed in patients with lower baseline viral load (< or =6 x 10(5) IU/mL) [88.2% versus 79.5% in patients with higher baseline viral load (> or = 6 x 10(5) IU/mL), P=0.684] and statistically lower proportion of SVR wasn't observed in patients infected with HCV genotype 1 (76.9% versus 92.9% in patients infected with HCV genotype non-1, P = 0.363). The higher rates of SVR were observed in patients with IL28B genotype CC than patients with genotype CT in the group of higher baseline viral load (> or = 6 x 10(5) IU/mL) (87.5% versus 42.9%, P=0.033) and in HCV genotype 1 infected patients (89.7% versus 50.0%, P=0.025). CONCLUSION: CC genotype was accounted for the majority at rs12979860 in patients of the Sichuan region of China. The higher rates of SVR were observed in IL28B genotype CC than genotype CT. Compared to HCV viral genotype and baseline viral load, IL28B genotype may predict the treatment effect of greater value.

[Lamivudine-resistant analysis and management for chronic hepatitis B patients with initial lamivudine therapy].

OBJECTIVE: To study the factors influencing the long-term usage of lamivudine (LAM) in chronic hepatitis B (CHB) patients and the management after drug-resistance. METHODS: 383 cases of naive CHB patients in our outpatient clinic were treated with lamivudine (100 mg/d) and followed up for at least over 1 year from 2001 to 2010. 129 cases encountered lamivudine-resistance and were then divided into two groups: patients in group A were switched to adefovir dipivoxil (ADV) alternative treatment and those patients in group B were added with ADV for continuous treatment. Efficacy assessment factors included serum HBV markers, HBV DNA, ALT, AFP and other biochemical indicators. RESULTS: Among the 383 cases, patients with HBV DNA negative conversion (PCR below test line) at 3 months, 6 months, 1 year, 2 years, 3 years and > 3 years after initial treatment were respectively 156 cases (40.7%), 213 cases (55.6%), 228 cases (59.5% ), 217cases (56.7%), 214 cases (55.9%) and 213 cases (55.6%). HBeAg/HBeAb seroconversion occurred in 62 cases (22.6%). 12 cases were found with primary LAM resistance, 129 cases with HBV breakthrough and rebound, the cumulative resistance rate was 36.8% and the cumulative rebound rate was 34.8%. High baseline viral load, baseline ALT levels < 2 ULN, Lower virologic response rate at week 24 were associated with a higher rebound rate (chi2 is 35.716, 8.728, 43.534, respectively, all with P < 0.01).Viral breakthrough and rebound occurred in 112 patients (86.8%) within 1 year and a half, 123 patients (95.3%) occurred at the end of 2 years and no patient with viral breakthrough and rebound after 5 years. For the patients with viral rebound in group A and group B, the rates of HBV DNA loss were 22.7% (15/66) and 58.7% (37/63) respectively, and the viral response rates were 59.1% (39/66) and 87.3% (52/63) respectively, with chi2 values equaled 17.364 and 12.975 respectively (P < 0.01). CONCLUSION: For the chronic hepatitis B patients on initial treatment with lamivudine, the viral rebound occurred mainly within 2 years. LAM combined with ADV is more effective than ADV alone for lamivudine-resistant patients.

[Association between the influential factors and the effectiveness of pegylated interferon alpha-2a plus ribavirin as a combination treatment for chronic hepatitis C patients].

To evaluate the efficacy and to investigate the association between the length of the treatment period and the cumulative dose of pegylated interferon alpha-2a (PegIFN alpha-2a) plus ribavirin (RBV) and the effectiveness of antiviral therapy. We analyzed data from 117 patients treated for 48 weeks with PEG-IFN alpha-2a (135mug or 180mug/week) plus weight-based RBV (800 mg/d for patients is less than or equal to 65 kg, 1000 mg/d for patients 65-75 kg and 1200 mg/d for patients is more than or equal to 75 kg) under care at West China Hospital. HCV RNA was assessed at baseline, Week 4, 12 and 24, the end of treatment (EOT) and after 24 weeks follow-up (sustained virological response; SVR) with a test range of 1.0*10(3) to 5.0*10(7) IU/ml. Patients were stratified by age, gender, weight, route of transmission, duration of infection, baseline HCV RNA level and PegIFN alpha-2a or RBV dosage. HCV genotype was assessed in 29 patients (genotype 1b, 21; genotype 2a, 7; genotype 1b/2a, 1). Rapid virological response (RVR; HCV RNA negative at week 4), complete early virological response (cEVR; HCV RNA negative at week 12), EOT response, and SVR were achieved in 88 (75.2%), 110 (94%), 114 (97.4%) and 96 (82.1%) patients, respectively. Younger age, lower weight and shorter speculated infection years were associated with higher SVR rates (91.4% vs 72.9%, x2=6.796, P value is less than 0.05; 85% vs 50%, x2=5.433, P value is less than 0.05; 96.7% vs 77%, x2=5.852, P value is less than 0.05). SVR significantly increased with treatment length (38.5%, 66.7%, and 88.8% for is less than or equal to 29 weeks, 29-38 weeks, and is more than or equal to 38 weeks, respectively). SVR significantly increased with total cumulative treatment doses (38.5%, 66.7% and 88.8% for is less than or equal to 60%, 60%-80% and is more than or equal to 80% of PegIFN dose respectively; 33.3%, 85.3% and 96.8% for is less than or equal to 60%, 60%-80% and is more than or equal to 80% in RBV dose respectively) in all patients. Less than 80% of standard dose of RBV was not sufficient even if given enough PegIFN (is more than or equal to 80% cumulative treatment dose) in patients who achieved RVR. Chinese patients treated with peginterferon alpha-2a plus ribavirin have high rates of SVR. It is important to complete the target length of treatment and to continue the target dosage to achieve SVR.

Histological changes in chinese chronic hepatitis B patients with ALT lower than two times upper limits of normal.

The role of ALT as a predictor of liver injury has been questioned. The aim of this study is to use liver biopsy to assess the degree of liver injury in patients with chronic hepatitis B(CHB) whose ALT < 2 x upper limit of normal (ULN). A total of 49.2% of patients in this study had significant inflammation (grade >or=2) and 36.4% had significant fibrosis (stage >or=2). The frequency of serious inflammation and fibrosis was similar in patients with different ALT levels. The level of serum HBV DNA was not significantly associated with the extent of inflammation and fibrosis. Advanced age was a significant independent predictor of histological damage and the presence of more significant inflammation and fibrosis. We conclude that many CHB patients with ALT < 2 x ULN have significant liver inflammation or fibrosis and that liver biopsy is necessary to assess liver damage and should be used to assess the need for anti-viral therapy.

[Analysis of genomic DNA methylation level in radish under cadmium stress by methylation-sensitive amplified polymorphism technique].

The level of cytosine methylation induced by cadmium in radish (Raphanus sativus L.) genome was analysed using the technique of methylation-sensitive amplified polymorphism (MSAP). The MSAP ratios in radish seedling exposed to cadmium chloride at the concentration of 50, 250 and 500 mg/L were 37%, 43% and 51%, respectively, and the control was 34%; the full methylation levels (C(m)CGG in double strands) were at 23%, 25% and 27%, respectively, while the control was 22%. The level of increase in MSAP and full methylation indicated that de novo methylation occurred in some 5'-CCGG sites under Cd stress. There was significant positive correlation between increase of total DNA methylation level and CdCl(2) concentration. Four types of MSAP patterns: de novo methylation, de-methylation, atypical pattern and no changes of methylation pattern were identified among CdCl(2) treatments and the control. DNA methylation alteration in plants treated with CdCl(2) was mainly through de novo methylation.