Carvedilol Plus NUC for Patients With HBV-Compensated Cirrhosis Under Virological Suppression: A Randomized Open-Label Trial

INTRODUCTION

Portal hypertension progression can be relieved after controlling the etiology of liver cirrhosis. Whether beta-blockers could additionally enhance the effects during treatment, particularly for small esophageal varices (EV), was unclear. This study aims to assess the efficacy of add-on carvedilol to delay EV progression during anti-hepatitis B virus (HBV) treatment in HBV-related cirrhosis.

METHODS

This randomized controlled trial enrolled patients with virologically suppressed HBV-compensated cirrhosis and small/medium EV. The participants were randomly assigned to receive nucleos(t)ide analog (NUC) or carvedilol 12.5 mg plus NUC (1:1 allocation ratio). The primary end point was the progression rate of EV at 2 years of follow-up.

RESULTS

A total of 238 patients (small EV, 77.3%) were randomized into 119 NUC and 119 carvedilol plus NUC (carvedilol [CARV] combination group). Among them, 205 patients (86.1%) completed paired endoscopies. EV progression rate was 15.5% (16/103) in the NUC group and 12.7% (13/102) in the CARV combination group (relative risk = 0.79, 95% confidence interval 0.36-1.75, P = 0.567). Subgroup analysis on medium EV showed the CARV combination group had a more favorable effect in promoting EV regression (43.5% vs 13.1%, P = 0.022) than NUC alone, but not in small cases ( P = 0.534). The incidence of liver-related events (decompensation, hepatocellular carcinoma, or death/liver transplantation) within 2 years was similar between the 2 groups (11.2% vs 10.4%, P = 0.881).

DISCUSSION

The overall results did not show statistically significant differences between the added carvedilol strategy and NUC monotherapy in preventing EV progression in patients with virologically suppressed HBV-compensated cirrhosis. However, the carvedilol-added approach might offer improved outcomes specifically for patients with medium EV (NCT03736265).

Regression of Liver Fibrosis in Patients on Hepatitis B Therapy Is Associated With Decreased Liver-Related Events

BACKGROUND & AIMS

Liver fibrosis in patients with chronic hepatitis B can regress with successful antiviral therapy. However, the long-term clinical benefits of fibrosis regression have not been fully elucidated. This study investigated the association between biopsy-proven fibrosis regression by predominantly progressive, indeterminate, and predominantly regressive (P-I-R) score and liver-related events (LREs) in chronic hepatitis B patients.

METHODS

Patients with on-treatment liver biopsy and significant fibrosis/cirrhosis (Ishak stage ≥3) were included in this analysis. Fibrosis regression was evaluated according to the P-I-R score of the Beijing Classification. LREs were defined as decompensations, hepatocellular carcinoma, liver transplantation, or death. The Cox proportional hazards model was used to determine associations of fibrosis regression with LREs.

RESULTS

A total of 733 patients with Ishak stages 3/4 (n = 456; 62.2%) and cirrhosis (Ishak stages 5/6; n = 277; 37.8%) by on-treatment liver biopsy were enrolled. According to the P-I-R score, fibrosis regression, indeterminate, and progression were observed in 314 (42.8%), 230 (31.4%), and 189 (25.8%) patients, respectively. The 7-year cumulative incidence of LREs was 4.1%, 8.7%, and 18.1% in regression, indeterminate, and progression, respectively (log-rank, P < .001). Compared with patients with fibrosis progression, those with fibrosis regression had a lower risk of LREs (adjusted hazard ratio, 0.40; 95% CI, 0.16-0.99; P = .047), followed by the indeterminate group (adjusted hazard ratio, 0.86; 95% CI, 0.40-1.85; P = .691). Notably, this favorable association also was observed in patients with cirrhosis or low platelet counts (<150 × 109/L).

CONCLUSIONS

Antiviral therapy-induced liver fibrosis regression assessed by P-I-R score is associated with reduced LREs. This shows the utility of histologic fibrosis regression assessed by on-treatment P-I-R score as a surrogate endpoint for clinical events in patients with hepatitis B virus-related fibrosis or early cirrhosis.

Distinct on-treatment HCC risks associated with different decompensation events in HBV patients with cirrhosis

OBJECTIVES

Long-term treatment with nucleoside analog (NA) reduces the risks for decompensation and hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients with compensated cirrhosis (CC). However, whether antiviral therapy has differential efficacy on the risks for decompensation and HCC is insufficiently elucidated. Therefore, we investigated the disease state transition, focusing on decompensation event-specific HCC risk in NA-treated CHB patients with CC.

METHODS

We prospectively followed up on 1163 NA-treated CHB patients with CC every six months for up to seven years. The cumulative incidence and risk of HCC were analyzed by the Kaplan-Meier method and competing risk model. The multistate model was used to estimate the transition probabilities to HCC from different disease states.

RESULTS

HCC predominated the first liver-related events, with a 5-year cumulative incidence of 9.0%, followed by decompensation (8.3%, including 7.9% nonbleeding decompensation and 2.4% variceal bleeding) and 0.2% death. The decompensation stage had a significantly higher 5-year cumulative HCC incidence than the CC stage (27.6% vs. 9.1%; HR = 2.42, 95% CI: 1.24, 4.71). Furthermore, nonbleeding decompensation events had a higher 5-year transition probability to HCC than bleeding (27.6% vs. 15.8%; HR = 2.69, 95% CI: 1.41, 4.17). Viral suppression modified the on-treatment transition risk to HCC (1-year: HR = 0.45, 95% CI: 0.28, 0.73; 3-year: HR = 0.23, 95% CI: 0.14, 0.38). An online calculator was developed to facilitate HCC risk stratification.

CONCLUSIONS

In NA-treated CHB patients with compensated cirrhosis, the risk was higher for HCC than for decompensation; more importantly, different decompensation events conferred distinct HCC risks.

Anti-Tumor Effects of Carrimycin and Monomeric Isovalerylspiramycin I on Hepatocellular Carcinoma in Vitro and in Vivo

Hepatocellular carcinoma results in a high risk of second primary malignancies and has prominent morbidity and mortality. There is a lack of effective treatment and prognosis is poor. Therefore, effective drugs need to be discovered. Carrimycin is a 16-member macrolide antibiotic with anticancer activity, and monomeric isovalerylspiramycin I is a main component. The aim of this study was to determine the anti-tumor effects of carrimycin and monomeric isovalerylspiramycin I on hepatocellular carcinoma through in vivo and in vitro experiments. In vitro, changes in cellular proliferation, migration, invasion, and apoptosis were analyzed by MTT, colony formation, EdU labeling, wound-healing, matrigel transwell invasion, and flow cytometric assays using SK-Hep1, Hep3B, SNU-354, SNU-387 hepatocellular carcinoma cell lines. Western blotting and RT-PCR were used to detect the effects of carrimycin and monomeric isovalerylspiramycin I on the expression levels of vascular endothelial growth factor (VEGF) and programmed death ligand 1 (PD-L1). Nude mice were subcutaneously transplanted with SK-Hep1 cells or C57BL/6J mice were orthotopically transplanted with hepatocarcinoma H22 cells. Tumor volume, pathological changes in tumor tissues, and the concentration of VEGF in mouse serum were measured after treatments. Carrimycin and monomeric isovalerylspiramycin I dose-dependently inhibited hepatocellular carcinoma cell viability, colony formation, and DNA replication. These agents markedly suppressed migration and invasion and promoted apoptosis of the cell lines. Western blotting and RT-PCR demonstrated that carrimycin and monomeric isovalerylspiramycin I reduced VEGF and PD-L1 protein and mRNA levels in a dose-dependent manner. In vivo studies further confirmed that carrimycin and monomeric isovalerylspiramycin I could significantly inhibit tumor growth, tumor histopathological alterations, and the concentration of VEGF in both mouse tumor models. These results show that carrimycin and monomeric isovalerylspiramycin I promoted apoptosis and inhibited proliferation, migration, and invasion of hepatocellular carcinoma cells. Therefore, our discovery suggests anti-tumor capacity for carrimycin and monomeric isovalerylspiramycin I and provides data on potential new drugs for inhibiting hepatocellular carcinoma.

Screening varices in patients with HBV-related cirrhosis on antiviral therapy: Platelet alone or together with LSM

BACKGROUND & AIMS

Non-invasive assessment criteria to rule out high-risk varices (HRV) in compensated hepatitis B virus (HBV) cirrhosis on antiviral therapy remains unclear.

METHODS

HBV-related compensated cirrhotic patients who underwent screening endoscopy during antiviral therapy were enrolled and randomly divided into the derivation and validation sets. HRV were defined as medium to large varices or small varices with red signs. Univariate and multivariate logistic analysis were used to determine the parameters associated with HRV.

RESULTS

A total of 436 HBV-related compensated cirrhotic patients screened for varices were enrolled, the median duration of antiviral therapy was 4 years (IQR: 2.5-5.5 years). In the derivation set (N = 290, 17.2% with HRV), only platelet (PLT) count (OR = 0.972, 95% CI 0.961-0.984, P < .05) was independently associated with HRV, whereas liver stiffness measurement was not associated with the presence of HRV. With a PLT count cut-off value of 105 × 10⁹ /L, unnecessary endoscopies could be spared in 56.9% patients, with a 3.6%. risk of missing HRV. In the validation cohort (N = 146, 16.4% with HRV), the proportion of patients that could safely spare endoscopies (61.0%) identified by this PLT count cut-off value was higher than that obtained by using Baveno VI criteria (34.9%), with an acceptable risk of missing HRV (3.4%).

CONCLUSION

Compared with the 'Baveno VI criteria or beyond' criteria, PLT count higher than 105 × 10⁹ /L could safely spare more screening endoscopies without increasing the risk of missing HRV in patients with HBV-related compensated cirrhosis on antiviral therapy.

A Predictive Model Using N-Glycan Biosignatures for Clinical Diagnosis of Early Hepatocellular Carcinoma Related to Hepatitis B Virus

Early diagnosis of hepatic cancer is a major public health challenge. While changes in serum N-glycans have been observed as patients progress from liver fibrosis/cirrhosis to hepatocellular carcinoma (HCC), the predictive performance of N-glycans is yet to be determined for HCC early diagnosis as well as differential diagnosis from liver fibrosis/cirrhosis. In a total sample of 247 patients with hepatitis B virus-related liver disease, we characterized and compared the serum N-glycans in very early/early and intermediate/advanced stages of HCC and those with liver fibrosis/cirrhosis. Additionally, we performed a retrospective timeline analysis of the serum N-glycans 6 and 12 months before a diagnosis of the very early/early stage of HCC (EHCC). A predictive model was built, named hereafter as Glycomics-EHCC, incorporating the glycan peaks (GPs) 1, 2, and 4. The model showed a larger area under the receiver operating characteristic curve compared with a traditional model with the α-fetoprotein (0.936 vs. 0.731, respectively). The Glycomics-EHCC model had a sensitivity of 84.6% and specificity of 85.0% at a cutoff value of -0.39 to distinguish EHCC from liver fibrosis/cirrhosis. Moreover, the Glycomics-EHCC model was able to forecast a future EHCC diagnosis with a sensitivity and specificity over 90% and 85%, respectively, using the serum N-glycan biosignatures 6 or 12 months earlier when the patients were suffering from liver fibrosis/cirrhosis before being diagnosed with EHCC. This serum glycomic biosignature model warrants further clinical studies in independent population samples and offers promise to forecast EHCC and its differential diagnosis from liver fibrosis/cirrhosis.

Convallatoxin promotes apoptosis and inhibits proliferation and angiogenesis through crosstalk between JAK2/STAT3 (T705) and mTOR/STAT3 (S727) signaling pathways in colorectal cancer

BACKGROUND

Aberrant activation of STAT3 is frequently encountered and promotes survival, cellular proliferation, migration, invasion and angiogenesis in tumor cell. Convallatoxin, triterpenoid ingredient, exhibits anticancer pharmacological properties.

PURPOSE

In this work, we investigated the anticancer potential of convallatoxin and explored whether convallatoxin mediates its effect through interference with the STAT3 activation in colorectal cancer cells.

METHODS

In vitro, the underlying mechanisms of convallatoxin at inhibiting STAT3 activation were investigated by homology modeling and molecular docking, luciferase reporter assay, MTT assay, RT-PCR, Western blotting and immunofluorescence assays. Changes in cellular proliferation, apoptosis, migration, invasion and angiogenesis were analyzed by EdU labeling assay, colony formation assay, flow cytometry assay, wound-healing assay, matrigel transwell invasion assay and tube formation assays. And in vivo, antitumor activity of convallatoxin was assessed in a murine xenograft model of HCT116 cells.

RESULTS

Convallatoxin decreased the viability of colorectal cancer lines. Moreover, convallatoxin reduced the P-STAT3 (T705) via the JAK1, JAK2, and Src pathways and inhibited serine-727 phosphorylation of STAT3 via the PI3K-AKT-mTOR-STAT3 pathways in colorectal cancer cells. Interestingly, we discovered the crosstalk between mTOR and JAK2 in mTOR/STAT3 and JAK/STAT3 pathways, which collaboratively regulated STAT3 activation and convallatoxin play a role in it. Convallatoxin also downregulated the expression of target genes involved cell survival (e.g., Survivin, Bcl-xl, Bcl-2), proliferation (e.g., Cyclin D1), metastasis (e.g., MMP-9), and angiogenesis (e.g., VEGF). Indeed, we found that convallatoxin inhibited tube formation, migration, and invasion of endothelial cells, and inhibited the proliferation. Finally, in vivo observations were confirmed by showing antitumor activity of convallatoxin in a murine xenograft model.

CONCLUSION

The result of the current study show that convallatoxin promotes apoptosis and inhibits proliferation and angiogenesis through crosstalk between JAK2/STAT3 (T705) and mTOR/STAT3 (S727) signaling pathways in colorectal cancer cells and indicate that convallatoxin could be a valuable candidate for the development of colorectal cancer therapeutic.

Baseline Characteristics and Treatment Patterns of the Patients Recruited to the China Registry of Hepatitis B

Background and Aims: Chronic hepatitis B virus (HBV) infection remains a major public health problem globally. Here, we describe the baseline characteristics and treatment profiles of HBV-infected patients recruited to the China Registry of Hepatitis B. Methods: Inclusion criteria were patients with different stages of chronic HBV infection and complete key data. Exclusion criteria were patients with hepatocellular carcinoma. The baseline clinical, laboratory and treatment profiles were analyzed. Results: Finally, 40,431 patients were included. The median age was 43 years, with 65.2% being men and 51.3% being positive for hepatitis B e antigen (HBeAg). The most common initial diagnosis was chronic hepatitis B (81.0%), followed by cirrhosis (9.3%), inactive carrier of hepatitis B surface antigen (HBsAg) (6.7%), and immune tolerant phase of hepatitis B infection (3.0%). Among the 21,228 patients who were on treatment, 88.0%, 10.0% and 2.0% received nucleos(t)ide analogues (NAs), interferon or combination of NAs and interferon, respectively. The proportion of patients who received preferred NAs (entecavir or tenofovir disoproxil fumarate) had increased from 13.5% in 2003 to 79.7% in 2016. Conclusions: We concluded that middle-aged men accounted for most of the patients with chronic hepatitis B in this cross-sectional study. About half of the patients were HBeAg-positive. NAs were the most commonly used therapy, and use of the preferred NAs had steadily increased in the past decade.

Early steep decline of liver stiffness predicts histological reversal of fibrosis in chronic hepatitis B patients treated with entecavir

It is unknown whether dynamic changes of liver stiffness measurement (LSM) can predict the reversibility of fibrosis. Therefore, we evaluated the utility of LSM changes in predicting histological changes of fibrosis in patients with chronic hepatitis B (CHB) on antiviral therapy. In a prospective cohort of CHB patients treated with entecavir, virological measurement and biochemical measurement along with LSM were measured at baseline and every 6 months. Liver biopsies were conducted at baseline and month 18 of treatment. Fibrosis regression was defined by the following two criteria: (a) Ishak score decrease ≥1 stage, (b) Ishak score decrease ≥1 stage or predominantly regressive by post-treatment PIR classification. The dynamic changes of LSM and its predictive value for histological reversibility were evaluated with piecewise linear mixed-effects model and ROC analysis. We found that at month 18 of antiviral therapy, liver fibrosis was reserved in 86 of 212 (40.6%) CHB patients by Ishak reversal criterion. Overall, a decline in LSM was associated with attenuation of Ishak score. The rate of LSM decline in the first 6 months was significantly faster in patients with fibrosis reversal (ΔLSM%_Ishak  = -2.19%/month, P = 0.0025; ΔLSM%_Ishak/PIR  = -2.56%/month, P = 0.0004). The predictive model based on baseline FIB-4 and Ishak score as well as baseline LSM, PLT, albumin and their changes during the first 6 months could predict histological reversal (AUROC_Ishak  = 0.74, 95% CI: 0.67-0.80; AUROC_Ishak/PIR  = 0.81, 95% CI: 0.74-0.87). We conclude that in CHB patients, changes in LSM during the first 6 months of entecavir therapy can predict histological reversibility of liver fibrosis at month 18 of antiviral therapy.

On-treatment changes of serum Wisteria floribunda agglutinin-positive Mac-2 binding protein are associated with the regression of liver fibrosis in chronic hepatitis B patients on interferon α add-on therapy

Wisteria floribunda agglutinin-positive Mac-2-binding protein (M2BP) has been identified as a predictor for the response of interferon α (IFN-α) in patients with viral hepatitis. However, whether serum glycosylation isomer of M2BP (M2BPGi) was associated with the regression of liver fibrosis in patients with chronic hepatitis B (CHB) during IFN-α add-on therapy is still unknown. CHB patients were treated with entecavir for 26 weeks followed by entecavir plus pegylated IFN-α for 52 weeks. Liver biopsies were taken at baseline and treatment week 78. The regression of fibrosis was identified according to Ishak standard or Ishak plus Progressive-Indeterminate-Regressive (P-I-R) standard. Serum M2BPGi and liver function tests were measured at baseline and every 26 weeks of treatment. A total of 72 CHB patients were included in the present study. Serum M2BPGi was correlated with fibrosis and necroinflammation both at baseline and week 78. If Ishak standard was used as the reference, only the percent change of M2BPGi at week 52 from week 26 (Δ%M2BPGi_26w-52W ) was independently associated with fibrosis regression at treatment week 78, the area under the ROC curve (AUROC) of Δ%M2BPGi_26w-52W for predicting fibrosis regression was 0.705. As for Ishak plus P-I-R standard, the AUROC of the predictive model for fibrosis regression (0.896*M2BPGi_52W  + 0.363*necroinflammation score_0w  + 2.051*Ishak score_0w  - 4.489) was 0.888. These data indicated that dynamic changes of serum M2BPGi were associated with fibrosis regression in CHB patients on IFN-α add-on therapy.

Combination of entecavir with thymosin alpha-1 in HBV-related compensated cirrhosis: a prospective multicenter randomized open-label study

ABSTRACT Background: Thymosin alpha-1 (Ta-1) suppresses HBV viral replication, while the evidence of combination effect with nucleoide is still limited. We aimed to investigate the efficacy and safety of combination therapy of Ta-1 with entecavir (ETV) in patients with compensated liver cirrhosis.

RESEARCH DESIGN AND METHODS

A total of 690 patients were randomized to receive Ta-1 plus ETV (n = 351) or ETV monotherapy (n = 339) for 52 weeks after 26 weeks of ETV treatment, followed by continued entecavir therapy. The primary endpoint was defined as liver decompensation, hepatocellular carcinoma (HCC) or death.

RESULTS

The median followed up was 38.2 months. The cumulative incidence of liver decompensation, HCC, or death were similar between two groups. During the Ta-1 combination treatment, the HCC incidence was 1.7% in combination group and 2.1% in ETV group, without new HCC cases developed during week 39 to week 77 in combination group. The virologic response, serologic response, biochemical response was similar between two groups at week 104. Both therapies were well-tolerated.

CONCLUSION

There was no significant difference between two groups in endpoint events, while combination therapy with Ta-1 has a tendency to inhibit the development of HCC.

On-treatment changes of liver stiffness at week 26 could predict 2-year clinical outcomes in HBV-related compensated cirrhosis

BACKGROUND & AIMS

It is unclear whether liver stiffness measurement (LSM) dynamic changes after anti-HBV treatment could predict the risk of liver-related events (LREs), particularly in patients with HBV-related compensated cirrhosis.

METHODS

Treatment-naïve patients with HBV-related compensated cirrhosis were enrolled. All patients were under entecavir-based antiviral therapy, and followed up every 26 weeks for 2 years. The association between LSM and LREs was analysed by Cox proportional hazard model and Harrell C-index analysis.

RESULTS

A total of 438 patients were included in the study. At the follow-up of 104 weeks, LREs developed in 33/438 (7.8%) patients, including 16 episodes of decompensation, 18 HCC and 3 deaths. The median LSM remained high from 20.9, 18.6, 20.4 to 20.3 Kpa at week 0, 26, 52 and 78 among patients with LREs, whereas the LSM decreased from 17.8, 12.3, 10.6 to 10.2 Kpa in patients without LREs respectively. Percentage changes of LSM at 26 weeks from baseline were significantly associated with LREs (excluding 11 cases occurred within the first 26 weeks), with a crude hazard ratio of 2.94 (95% CI: 1.73-5.00) and an albumin-adjusted hazard ratio of 2.47 (95% CI: 1.49-4.11). The Harrell C-index of these 2 models for predicting 2-year LREs were 0.68 (95% CI: 0.56-0.80) and 0.75 (95% CI: 0.65-0.85) respectively. Nomograms were developed to identify individuals at high risk for point-of-care application.

CONCLUSIONS

Dynamic changes of LSM alone, or combined with baseline albumin, could predict LREs in patients with HBV-related compensated cirrhosis during antiviral therapy.

New classification of liver biopsy assessment for fibrosis in chronic hepatitis B patients before and after treatment

Liver fibrosis is the net result of dynamic changes between fibrogenesis and fibrolysis. Evidence has shown that antiviral therapy can reverse liver fibrosis or even early cirrhosis caused by hepatitis B virus. However, current evaluation systems mainly focus on the severity of, but not the dynamic changes in, fibrosis. Here, we propose a new classification to evaluate the dynamic changes in the quality of fibrosis, namely: predominantly progressive (thick/broad/loose/pale septa with inflammation); predominately regressive (delicate/thin/dense/splitting septa); and indeterminate, which displayed an overall balance between progressive and regressive scarring. Then, we used this classification to evaluate 71 paired liver biopsies of chronic hepatitis B patients before and after entecavir-based therapy for 78 weeks. Progressive, indeterminate, and regressive were observed in 58%, 29%, and 13% of patients before treatment versus in 11%, 11%, and 78% after treatment. Of the 55 patients who showed predominantly regressive changes on posttreatment liver biopsy, 29 cases (53%) had fibrosis improvement of at least one Ishak stage, and, more interestingly, 25 cases (45%) had significant improvement in terms of Laennec substage, collagen percentage area, and liver stiffness despite remaining in the same Ishak stage.

CONCLUSION

This new classification highlights the importance of assessing and identifying the dynamic changes in the quality of fibrosis, especially relevant in the era of antiviral therapy.(Hepatology 2017;65:1438-1450).

TRIP12 as a mediator of human papillomavirus/p16-related radiation enhancement effects

Patients with human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) have better responses to radiotherapy and higher overall survival rates than do patients with HPV-negative HNSCC, but the mechanisms underlying this phenomenon are unknown. p16 is used as a surrogate marker for HPV infection. Our goal was to examine the role of p16 in HPV-related favorable treatment outcomes and to investigate the mechanisms by which p16 may regulate radiosensitivity. HNSCC cells and xenografts (HPV/p16-positive and -negative) were used. p16-overexpressing and small hairpin RNA-knockdown cells were generated, and the effect of p16 on radiosensitivity was determined by clonogenic cell survival and tumor growth delay assays. DNA double-strand breaks (DSBs) were assessed by immunofluorescence analysis of 53BP1 foci; DSB levels were determined by neutral comet assay; western blotting was used to evaluate protein changes; changes in protein half-life were tested with a cycloheximide assay; gene expression was examined by real-time polymerase chain reaction; and data from The Cancer Genome Atlas HNSCC project were analyzed. p16 overexpression led to downregulation of TRIP12, which in turn led to increased RNF168 levels, repressed DNA damage repair (DDR), increased 53BP1 foci and enhanced radioresponsiveness. Inhibition of TRIP12 expression further led to radiosensitization, and overexpression of TRIP12 was associated with poor survival in patients with HPV-positive HNSCC. These findings reveal that p16 participates in radiosensitization through influencing DDR and support the rationale of blocking TRIP12 to improve radiotherapy outcomes.

Hypoxia-ischemia brain damage disrupts brain cholesterol homeostasis in neonatal rats

PURPOSE

The first 3 weeks of life is the peak time of oligodendrocytes development and also the critical period of cholesterol increasing dramatically in central nervous system in rats. Neonatal hypoxia-ischemia (HI) brain damage happening in this period may disturb the brain cholesterol balance as well as white matter development.

MATERIALS AND METHODS

To test this hypothesis, postnatal day 7 (P7) Sprague-Dawley rats were subjected to HI insult. Cholesterol concentrations from brain and plasma were measured. White matter integrity was evaluated by densitometric analysis of myelin basic protein (MBP) immunostaining and electron microscopy. Brain TNF-alpha and IL-6 levels were also measured.

RESULTS

HI-induced brain cholesterol, but not the plasma cholesterol, levels decreased significantly during the first three days after HI compared with naïve and sham operated rats (p<0.05). Obvious hypomyelination was indicated by marked reductions in MBP immunostaining on both P10 and P14 (p<0.01) and less and thinner myelinated axons were detected on P21 by electron microscopy observation. High expressions of brain TNF-alpha and IL-6 12 h after HI (p<0.05) were also observed.

DISCUSSION

The present work provides evidence that HI insult destroyed brain cholesterol homeostasis, which might be important in the molecular pathology of hypoxic-ischemic white matter injury. Proinflammatory cytokines insulting oligodendrocytes, may cause cholesterol unbalance. Furthermore, specific therapeutic interventions to maintain brain cholesterol balance may be effective for the recovery of white matter function.

Ghrelin stimulates milk intake by affecting adult type feeding behaviour in postnatal rats

The influence of ghrelin on feeding behaviour during infancy is unknown. To determine whether ghrelin influences milk intake in rat pups, newborn rats received a single i.p. injection of either rat ghrelin (100 microg/kg) or rabbit anti-ghrelin immunoglobulin G (100 microg/kg) every 5 days from postpartum day 5 to day 30 (P5-P30). Milk intake was then assessed by body weight gain following a 2-h suckling period. Ghrelin significantly increased weight gain relative to vehicle-injected controls in P20, P25 and P30 pups, but not in younger animals. Similarly, after 8 h of milk restriction, anti-ghrelin injections significantly decreased weight gain in P25 and P30, but not in younger pups. Interestingly, however, ghrelin did increase independent feeding in P10 and P15 pups using a paradigm in which pups consumed milk from a milk-soaked paper towel. We therefore conclude that ghrelin stimulates milk intake at an early postnatal stage, primarily by affecting adult-type feeding behaviour.

Biotransformation of letrozole in rat liver microsomes: effects of gender and tamoxifen

The in vitro metabolic kinetics of letrozole were investigated by incubating letrozole (10-500 microM) in female or male rat liver microsomes to assess the effect of gender and to predict the in vivo biotransformation characteristics of letrozole in rats. The effects of tamoxifen (TAM) on the metabolic kinetics of letrozole were also examined by incubating letrozole in female rat liver microsomes in the presence or absence of TAM. The effects of chronic pretreatment of female rats with TAM (0.5, 1.0, 5.0 mg/kg/day, i.p. for 7 consecutive days) on liver microsomal protein content and metabolic activity were also examined. The formation rate of the carbinol metabolite of letrozole, CGP44 645, was significantly higher (p<0.05) in male rat liver microsomes in comparison to female. The V(max)/K(m) ratio for letrozole metabolism in female rat liver microsomes did not change significantly (p>0.05) in the presence of TAM. After chronic pretreatment of female rats with TAM (up to a dose of 1.0mg/kg/day), the hepatic microsomal protein content was significantly increased but the formation rate of CGP44 645, when normalized for protein content, did not change significantly. These results suggest that there is a marked gender difference in letrozole metabolism in rats. It also appears that acute treatment of female rat liver microsomes with TAM produces negligible inhibitory effect on the CYP mediated metabolic clearance of letrozole. However, chronic pretreatment of female rats with TAM appear to induce CYPs, but does not significantly impact the metabolic activities of the enzymes associated with the formation of the carbinol metabolite of letrozole.

Determinant role of membrane helices in K ATP channel gating

The ATP-sensitive K(+) (K(ATP)) channels couple chemical signals to cellular activity, in which the control of channel opening and closure (i.e., channel gating) is crucial. Transmembrane helices play an important role in channel gating. Here we report that the gating of Kir6.2, the core subunit of pancreatic and cardiac K(ATP) channels, can be switched by manipulating the interaction between two residues located in transmembrane domains (TM) 1 and 2 of the channel protein. The Kir6.2 channel is gated by ATP and proton, which inhibit and activate the channel, respectively. The channel gating involves two residues, namely, Thr71 and Cys166, located at the interface of the TM1 and TM2. Creation of electrostatic attraction between these sites reverses the channel gating, which makes the ATP an activator and proton an inhibitor of the channel. Electrostatic repulsion with two acidic residues retains or even enhances the wild-type channel gating. A similar switch of the pH-dependent channel gating was observed in the Kir2.1 channel, which is normally pH- insensitive. Thus, the manner in which the TM1 and TM2 helices interact appears to determine whether the channels are open or closed following ligand binding.

A threonine residue (Thr71) at the intracellular end of the M1 helix plays a critical role in the gating of Kir6.2 channels by intracellular ATP and protons

ATP-sensitive K+ (K(ATP)) channels are known to be gated by several intracellular molecules, but the gating mechanisms remain unclear. To understand the relationship of channel gating to ligand binding, we studied Kir6.2 channel gating by ATP and protons, which inhibit and activate the channel, respectively. We have previously shown that a threonine residue (Thr71) is critical for the pH sensitivity of Kir6.2 channel. If this site is involved in channel gating rather than ligand binding, it should affect channel gating by both ATP and proton. To test this hypothesis we performed a mutation analysis. Site-specific mutations of Thr71 to a bulky residue reduced the ATP sensitivity by >100-fold and eliminated the pH sensitivity. Single-channel activity of these mutants was stabilized at the open state with no detectable rundown. Mutations to a small amino acid had little effect on the ATP and pH sensitivities. Mutations to intermediate amino acids reduced but did not abolish the ATP and pH sensitivities. Hydrophobicity is not critical, as both polar and nonpolar amino acids are found in each group. Mutation to a positively charged lysine markedly exacerbated the pH- but not ATP-sensitivity, whereas mutation to glutamate moderately reduced ATP and pH sensitivities. These results indicate that the residue mass is critical for Kir6.2 channel gating, a mass that should be below 120 daltons with no charge. The existence of such a site as Thr71 involved in channel gating by both ATP and proton suggests that channel gating in the K(ATP) channel likely is separate from ligand binding.

Requirement of multiple protein domains and residues for gating K(ATP) channels by intracellular pH

ATP-sensitive K(+) channels (K(ATP)) are regulated by pH in addition to ATP, ADP, and phospholipids. In the study we found evidence for the molecular basis of gating the cloned K(ATP) by intracellular protons. Systematic constructions of chimerical Kir6.2-Kir1.1 channels indicated that full pH sensitivity required the N terminus, C terminus, and M2 region. Three amino acid residues were identified in these protein domains, which are Thr-71 in the N terminus, Cys-166 in the M2 region, and His-175 in the C terminus. Mutation of any of them to their counterpart residues in Kir1.1 was sufficient to completely eliminate the pH sensitivity. Creation of these residues rendered the mutant channels clear pH-dependent activation. Thus, critical players in gating K(ATP) by protons are demonstrated. The pH sensitivity enables the K(ATP) to regulate cell excitability in a number of physiological and pathophysiological conditions when pH is low but ATP concentration is normal.

Cloning of rabbit alpha(1b)-adrenoceptor and pharmacological comparison of alpha(1a)-, alpha(1b)- and alpha(1d)-adrenoceptors in rabbit

We have isolated a cDNA clone of the rabbit alpha(1b)-adrenoceptor which has an open reading frame of 1557 nucleotides encoding a protein of 518 amino acids. The sequence shows higher identity to those of hamster, human, and rat alpha(1b)-adrenoceptors than to those of rabbit alpha(1a)- and alpha(1d)-adrenoceptors. The pharmacological binding properties of this clone expressed in Cos-7 cells showed a characteristic profile as alpha(1b)-adrenoceptor; high affinity for prazosin (pK(i)=10.3), relatively high affinity for tamsulosin (9.5) and low affinity for (-)-(R)-1-(3-hydroxypropyl)-5-[2-[[2-[2-(2,2, 2-trifluoroethoxy)phenoxy]ethyl]amino]propyl]indoline-7-carboxamid e (KMD3213) (8.5), 2-(2,6-dimethoxy-phenoxyethyl)-aminomethyl-1, 4-benzodioxane hydrochloride (WB4101) (8.7), and 8-[2-[4-(2-methoxy-phenyl)-L-piperazinyl]-8-azaspiro[4,5]decane-7, 9-dione dihydrochloride (BMY7378) (7.3). We have compared the levels of mRNA expression of three alpha(1)-adrenoceptor subtypes in rabbit tissues using the competitive reverse transcription/polymerase chain reaction (RT/PCR) assay. In most rabbit tissues except heart, alpha(1a)-adrenoceptor mRNA was expressed 10 folds more than the other two subtypes. However, binding experiments with [3H]prazosin and [3H]KMD3213 in rabbit tissues revealed a poor relationship between binding density and mRNA level. Especially, alpha(1b) binding sites were exclusively predominant in spleen, whereas the alpha(1b) subtype was minor at the mRNA level. These results indicate a high identity of structural and pharmacological profiles of three distinct alpha(1)-adrenoceptor subtypes between rabbit and other species, but there are species differences in their distribution.

[Usefulness of galea suturing method for scalp closure]

A method for scalp closure to prevent alopecia along a suture line is described. Only the galea is sutured. By tacking a sufficient width of the galea on both sides with an absorbable suture material, the sutured wound forms a ridge. The outer layer is then closed with skin staples to keep the blood circulation undisturbed. This procedure contrasts with the traditional method in which the galea is sutured with the overlying subcutaneous tissue and consequently the hair follicles are strangled. By adopting the method of suturing the galea, development of alopecia along a suture line has been effectively prevented and scarring has become less conspicuous.

Chemical, metabolic and immunological characterization of gangliosides of human glioma cells

The patterns of ganglioside profiles were studied in 10 human glioma and one melanoma cell lines. Ganglio-series gangliosides, GM3 (NeuAc alpha2-3Gal beta1-4Glc beta1-Cer) and GM2 (GalNAc beta 1-4 (NeuAc alpha2-3)Gal beta1-4Glc beta 1-1Cer), and a neolacto-series ganglioside, sialylparagloboside (SPG) (NeuAc alpha 2-3Gal beta1-4GlcNAc beta1-3Gal beta1-4Glc beta1-1Cer), were the predominant constituents. The activities of the two key enzymes, GM3 synthetase and lactotriaosyl ceramide (Lc3Cer) synthetase, alone did not account for the ganglioside profile. Metabolic labeling with the use of [3H]glucosamine-HCl showed more pronounced difference in the synthetic rate of each ganglioside type, in which GM2 was the most strongly labeled in 7 out of the 10 glioma cell lines. On quantifying the chemical content of GM3 and GM2, the GM3/GM2 molar ratio of above 2.0 was arbitrarily classified into GM3 dominant type (KG-1C and Mewo); the ratio below 0.5 was designated as GM2 dominant type (H4, U138MG, U373MG, T98G and A172); and the ratio between 0.5 and 2.0 was regarded as GM3 and GM2-co-dominant type (U87MG, Hs683, SW1088 and U118MG). Subsequently, the capabilities of the antibody binding to these gangliosides were examined in native forms in the cell membrane and in chemically-isolated forms. The intensity of reaction against chemically isolated GM3 and GM2 gangliosides was dependent on the quantity, and GM2 was more reactive than GM3; however, the reactivities on the cell surface did not correlate with the chemical content indicating other factors to influence their immunoreactivities.

[Effects of basic fibroblast growth factor on anoxia/reoxygenation injury of rat neonatal cardiomyocytes]

The effects of basic fibroblast growth factor (bFGF) on anoxia/reoxygenation (A/R) injury and protein kinase C (PKC) activity were studied on a model of A/R injury of neonatal rat cardiomyocytes to investigate the possibility of its using as a substrate for pharmacological preconditioning. The data indicated that bFGF improved the viability of cardiomyocytes, lowered the deplection of ATP and leakage of intracellular lactate dehydrogenase (LDH) in a concentration-dependent manner. PKC inhibitor, H7, completely abolished the protective effects. It was also found that bFGF directely activated PKC in cardiomyocytes in a time course similar to that in hypoxic preconditioning. The data suggested that the protective effect of bFGF on cardiomyocyte A/R injury might be mediated by PKC.

Cell density regulates crypticity of GM3 ganglioside on human glioma cells

Human glioma cell line KG-1C contains GM3 ganglioside as its sole glycolipid. The degree of M2590 antibody binding to GM3 was found to be regulated by the cell density; the percentage of positive cells in FACS analysis decreased from approximately 20% to close to none as the cells increased their density from sparse to confluent. The contents of GM3 with different cell densities were consistent, being more than 0.4 micromol/g of the cellular weight, which was high enough to be recognized by the antibody. Trypsin treatment of the cells did not increase antibody reactivity. The extracted GM3 retained its antigenicity, being intensely stained with M2590 on a TLC plate; there was no change in chromatographic mobility either, indicating no modification of its chemical structure. The fluorescent microscope disclosed scattered dot-like staining of GM3, particularly at the periphery of the cells. We were able to expose cryptic GM3 fully within 12 h by dispersion of the cells to a sparse density. Surface labeling of GM3 with the use of limited sodium periodate oxidation of sialylated residue equally labeled GM3 either from the confluent cells or the sparse cells. Disassembly of actin filaments with cytochalasin B (10 microM) partially exposed cryptic GM3 of confluent cells, indicating reversibility of the crypticity. All together, the results indicate that cryptic GM3 actually exists on the cell surface, hidden from the surface not by other molecules but by other mechanisms associated with the cellular architecture. We are beginning to explore the possibility of selective localization of GM3 in small caves or folds of the cell membrane produced upon cell-to-cell contact.

[Protective effects of methanolic extract of Oenanthe stolonifera (Roxb.) Wall. ex DC. on myocardial injury induced by ischemia and reperfusion in rats]

The methanolic extract Oenanthe stoloni fera iv, pretreatment can significantly prevent the arrhythmias induced by myocardial ischemia and reduce the myocardial infarct size in rats. It can also markedly prevent myocardial ischemia and reperfusion-induced arrhythmias. In addition, the methanolic extract of Oenanthe stoloni fera (100 mg/kg i.v.) helps significantly to decrease the MDA content and preserve the SOD activity in plasma.

[Chemical constituents of Ledebouriella seseloides Wolff]

Eleven compounds were isolated from the methanolic extraction of the radix of Ledebouriella seseloides. They were identified as beta-sitosterol, bergapten, hamaudol, daucosterine sec-O-glucosylhamaudol, 5-O-methylvisamminol, cimifugin, sucrose, 4-O-beta-glucopyranosyl-5-O-methyl-visamminol, prim-O-glucosylcimifugin and mannitol by physico-chemical constants and spectroscopic analysis.