Caspase-3 feedback loop enhances Bid-induced AIF/endoG and Bak activation in Bax and p53-independent manner

Chemoresistance in cancer has previously been attributed to gene mutations or deficiencies. Bax or p53 deficiency can lead to resistance to cancer drugs. We aimed to find an agent to overcome chemoresistance induced by Bax or p53 deficiency. Here, we used immunoblot, flow-cytometry analysis, gene interference, etc. to show that genistein, a major component of isoflavone that is known to have anti-tumor activities in a variety of models, induces Bax/p53-independent cell death in HCT116 Bax knockout (KO), HCT116 p53 KO, DU145 Bax KO, or DU145 p53 KO cells that express wild-type (WT) Bak. Bak knockdown (KD) only partially attenuated genistein-induced apoptosis. Further results indicated that the release of AIF and endoG also contributes to genistein-induced cell death, which is independent of Bak activation. Conversely, AIF and endoG knockdown had little effect on Bak activation. Knockdown of either AIF or endoG alone could not efficiently inhibit apoptosis in cells treated with genistein, whereas an AIF, endoG, and Bak triple knockdown almost completely attenuated apoptosis. Next, we found that the Akt-Bid pathway mediates Bak-induced caspase-dependent and AIF- and endoG-induced caspase-independent cell death. Moreover, downstream caspase-3 could enhance the release of AIF and endoG as well as Bak activation via a positive feedback loop. Taken together, our data elaborate the detailed mechanisms of genistein in Bax/p53-independent apoptosis and indicate that caspase-3-enhanced Bid activation initiates the cell death pathway. Our results also suggest that genistein may be an effective agent for overcoming chemoresistance in cancers with dysfunctional Bax and p53.

Testicular expression of NGF, TrkA and p75 during seasonal spermatogenesis of the wild ground squirrel (Citellus dauricus Brandt)

The nerve growth factor (NGF) not only has an essential effect on the nervous system, but also plays an important role in a variety of non-neuronal systems, such as the reproductive system. The aim of this study was to compare the quality and quantity in expression of NGF and its receptors (TrkA and p75) in testes of the wild ground squirrel during the breeding and nonbreeding seasons. Immunolocalization for NGF was detected mainly in Leydig cells and Sertoli cells in testes of the breeding and nonbreeding seasons. The immunoreactivity of TrkA was highest in the elongated spermatids, whereas p75 in spermatogonia and spermatocytes in testes of the breeding season. In the nonbreeding season testes, TrkA showed positive immunostainings in Leydig cells, spermatogonia and primary spermatocytes, while p75 showed positive signals in spermatogonia and primary spermatocytes. Consistent with the immunohistochemical results, the mean mRNA and protein level of NGF and TrkA were higher in the testes of the breeding season than in non-breeding season, and then decreased to a relatively low level in the nonbreeding season. In addition, the concentration of plasma gonadotropins and testosterone were assayed by radioimmunoassay (RIA), and the results showed a significant difference between the breeding and nonbreeding seasons with higher concentrations in breeding season. In conclusion, these results of this study provide the first evidence on the potential involvement of NGF and its receptor, TrkA and p75 in the seasonal spermatogenesis and testicular function change of the wild ground squirrel.

Emergence of a new GII.17 norovirus variant in patients with acute gastroenteritis in Jiangsu, China, September 2014 to March 2015

From September 2014 to March 2015, 23 outbreaks of norovirus (NoV) acute gastroenteritis occurred in Jiangsu, China. Partial sequencing of the NoV capsid gene suggested that 16 of the 23 outbreaks were related to a new GII.17 variant. This variant was first detected in sporadic specimens in October 2014, and became predominant in February 2015. Analysis of the RNA-dependent RNA polymerase (RdRp), and complete capsid including the protruding domain P2 sequences confirmed this GII.17 variant as distinct from previously identified GII variants.

Identification of Campylobacter jejuni and determination of point mutations associated with macrolide resistance using a multiplex TaqMan MGB real-time PCR

AIMS

The aim of the study was to develop a multiplex real-time PCR method to identify Campylobacter jejuni containing mutations commonly associated with macrolide resistance.

METHODS AND RESULTS

A multiplex fluorescence real-time PCR assay was developed based on TaqMan minor groove binder (MGB) probes. The VS1-MGB probe was designed based on the VS1 gene and was used to identify Camp. jejuni. The 23S rDNA-MGB probe was designed to distinguish macrolide resistance mutations in 23S rDNA, while 57D-MGB and 74D-MGB were designed to detect resistance mutations in ribosomal protein L4. The specificity and accuracy of our method were identical to the conventional biochemical tests, mapA PCR, minimum inhibitory concentration (MIC) determination and DNA sequencing. The linear detection limit of the method was 0·03 ng genomic DNA and three colony formation unit (CFU) per reaction. In 6 of 18 cases, the nature of Erythromycin resistance could be correctly determined from natural isolates; absence of the tested mutations was demonstrated in the remaining four resistant isolates.

CONCLUSIONS

A multiplex TaqMan MGB real-time PCR assay with high specificity and accuracy was developed to simultaneously identify Camp. jejuni and detect the gene mutations associated with macrolide resistance.

SIGNIFICANCE AND IMPACT OF THE STUDY

This multiplex method can potentially simplify the identification of Camp. jejuni and determine macrolide resistance due to mutations in 23S rDNA or ribosomal protein L4. This method has a potential for application in different research areas and molecular surveillance.

Markers of Autolysis in Acute ST Elevation Myocardial Infarction

INTRODUCTION

The availability of reliable noninvasive markers for infarct-related artery (IRA) patency status are very limited, otherwise could allow early identification of patients with patent IRA, for whom repeat thrombolysis or rescue percutaneous coronary intervention (PCI) are not necessary.

METHODS

We conducted a single centered retrospective study of STEMI patients undergoing primary PCI to determine how various factors such as demographic characteristics, risk markers of coronary heart disease, clinical and blood parameters present differently in patients with higher coronary flow and patent infarct related artery from patients with total occlusion at the time of initial angiography and how they affect in outcome of the disease.

RESULTS

MPV level (11.96 fL vs. 10.92 fL, P < 0.001), Lp (a) level (179.57 nmol/l vs 141.16 nmol/l , p < 0.001), CK-MB (290.2 vs. 190.98, P < 0.001), total cholesterol level (4.11 mmol/L vs. 3.8 mmol/L, p < 0.02) in total occlusion group were higher than in the patent IRA group. Wall motion abnormality was 77.2% for 203 patients with total occlusion group and 54.2% for 83 patients with patent IRA group (P<0.01). Mean hospital stay days were higher in total occlusion group as compared to the patent IRA group P < 0.01.

CONCLUSIONS

MVP, Lp (a), TC, and CK-MB levels and myocardial wall motion at the presentation may play the role of markers for IRA patency status that will help in early identification of patients with IRA, for whom repeat thrombolysis or rescue PCI may not be required.

The relationships among social support and quality of life in persons living with HIV/AIDS in Jiangxi and Zhejiang provinces, China

Several empirical studies, particularly those conducted in developed countries, have linked social support to quality of life among persons living with HIV/AIDS (PLWA). However, few studies have been conducted in developing countries, such as China; therefore, the question of any association being present between social support and quality of life in PLWA in China remains unanswered. This retrospective cross-sectional study was conducted to examine the relationships between social support and quality of life among PLWA in the Jiangxi and Zhejiang provinces of China. A total of 377 PLWA participated in this study, and questionnaires used included demographics, the Chinese Medical Outcomes Study Short Form-36, and a Social Support Rating Scale, all of which were collected through face-to-face interviews between 1 March and 15 April 2013 in six different County Centers of Disease Control and Prevention in Jiangxi and Zhejiang provinces, and one hospital in the Jiangxi. The health-related quality of life score was 64.7±13.5 (out of a total score of 100), which was significantly lower than the national norm level of 78.2±15.9. The total score of social support was 29.4±7.8 (full score 66). The canonical correlation between social support and quality of participants' lives was shown to be statistically significant (p<0.0001). The relationship between subjective support and quality of life among PLWA was also significant (p=0.004). Subjective support and the use of social support showed a positive correlation with vitality, role-physical, and role-emotional, and a negative correlation with body pain. The current study suggests that PLWA with lower social support have diminished quality of life.

Seasonal expression of androgen receptor, aromatase, and estrogen receptor alpha and beta in the testis of the wild ground squirrel (Citellus dauricus Brandt)

The aim of this study was to investigate the seasonal expression of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) mRNA and protein by real-time PCR and immunohistochemistry in the wild ground squirrel (WGS) testes. Histologically, all types of spermatogenic cells including mature spermatozoa were identified in the breeding season (April), while spermatogonia and primary spermatocytes were observed in the nonbreeding season (June), and spermatogonia, primary spermatocytes and secondary spermatocytes were found in pre-hibernation (September). AR was present in Leydig cells, peritubular myoid cells and Sertoli cells in the breeding season and pre-hibernation with more intense staining in the breeding season, whereas AR was only found in Leydig cells in the nonbreeding season; P450arom was expressed in Leydig cells, Sertoli cells and germ cells during the breeding season, whereas P450arom was found in Leydig cells and Sertoli cells during pre-hibernation, but P450arom was not present in the nonbreeding season; stronger immunohistochemical signal for ERα was present in Sertoli cells and Leydig cells during the breeding season; ERβ was only expressed in Leydig cells of the breeding season. Consistent with the immunohistochemical results, the mean mRNA level of AR, P450arom, ERα and ERβ were higher in the testes of the breeding season when compared to pre-hibernation and the nonbreeding season. These results suggested that the seasonal changes in spermatogenesis and testicular recrudescence and regression process in WGSs might be correlated with expression levels of AR, P450arom and ERs, and that estrogen and androgen may play an important autocrine/paracrine role to regulate seasonal testicular function.

Caspase-9 mediates Puma activation in UCN-01-induced apoptosis

The protein kinase inhibitor 7-hydroxystaurosporine (UCN-01) is one of the most potent and frequently used proapoptotic stimuli. The BH3-only molecule of Bcl-2 family proteins has been reported to contribute to UCN-01-induced apoptosis. Here we have found that UCN-01 triggers Puma-induced mitochondrial apoptosis pathway. Our data confirmed that Akt-FoxO3a pathway mediated Puma activation. Importantly, we elucidate the detailed mechanisms of Puma-induced apoptosis. Our data have also demonstrated that caspase-9 is a decisive molecule of Puma induction after UCN-01 treatment. Caspase-9 mediates apoptosis through two kinds of feedback loops. On the one hand, caspase-9 enhances Puma activation by cleaving Bcl-2 and Bcl-xL independent of caspase-3. On the other hand, caspase-9 directly activated caspase-3 in the presence of caspase-3. Caspase-3 could cleave XIAP in an another positive feedback loop to further sensitize cancer cells to UCN-01-induced apoptosis. Therefore, caspase-9 mediates Puma activation to determine the threshold for overcoming chemoresistance in cancer cells.

Gender differences in home environments related to childhood obesity in Nanchang, China

BACKGROUND

Childhood obesity is rapidly increasing in China, with rates doubling between 2000 and 2010. Several large, epidemiological studies have shown boys to be consistently more likely to be obese than girls. The aim of this study was to investigate gender differences in the home environment and parenting practices related to childhood obesity.

METHODS

A cross-sectional survey using a convenience sampling of 522 (86.1% response rate) primary caregivers of children ages 2-10 years was conducted in four locations in Nanchang, China, in the spring of 2013 using face-to-face, anonymous questionnaires.

RESULTS

Boys were significantly (p<0.05) more likely than girls to watch more television (TV) per week, be allowed to have snacks/sweets or soft drinks without permission, and to have sugary drinks at snacks and meals. Girls were significantly more likely than boys to have parental encouragement and support for physical activity, participate in organized sports/group activities, and have fresh fruits accessible. Parents also believed that boys eat too much junk foods or their favorite foods if not controlled. Few differences were noted in the actual physical environment in the home, including access to sports equipment, junk food availability, and access to media.

CONCLUSIONS

RESULTS indicate that parents tend to be more permissive with boys than girls, allowing them access to unhealthy foods and more TV time. These differences may contribute to the higher prevalence of obesity in boys in China.

Limited human-to-human transmission of avian influenza A(H7N9) virus, Shanghai, China, March to April 2013

In April 2013, two members of one family were successively confirmed as cases of avian influenza A(H7N9) virus infection in Shanghai, China. Respiratory specimens from the two cases and their close contacts were tested using real-time reverse-transcription (RT)-PCR. Paired serum specimens from contacts were tested by haemagglutination inhibition assay and microneutralisation test. The index patient developed severe pneumonia. Her husband presented with pneumonia shortly thereafter. Both cases had highly similar clinical features and infection with A(H7N9) virus was confirmed in both cases by genetic analysis. Phylogenetic analysis revealed a high level of similarity between the sequences from the two patients and environmental samples collected from wet markets in Minhang and Changning districts. Six samples from the Changning wet market were confirmed as A(H7N9) positive. Of 27 close contacts, one developed mild respiratory symptoms and another tested positive for A(H7N9) antibodies, but both were negative by real-time RT-PCR. The other 25 close contacts of both cases were A(H7N9) negative. Limited human-to-human transmission of the virus most likely occurred in the family cluster. However, other close contacts did not test positive for the virus, suggesting limited potential for extensive human-to-human transmission of the virus.

αNAC inhibition of the FADD-JNK axis plays anti-apoptotic role in multiple cancer cells

Nascent polypeptide-associated complex α (αNAC) is reportedly overexpressed in several types of cancers and regulates cell apoptosis under hypoxic conditions in HeLa cells. The aim of our study was to investigate the apoptotic function of αNAC in cancer progression. First, we observed the cellular effects of αNAC depletion. Mouse αNAC was used to restore the protein level and verify the effect. An Annexin V assay, a caspase activity reporter assay, an apoptotic molecular marker, and a colony formation assay were used as markers to investigate the mechanisms of cell death caused by αNAC depletion. The Cancer 10-pathway reporter assay was used to screen downstream pathways. PCR site-directed deletion based on the functional domains of αNAC was used to construct deletion mutants. Those functional domain deletion mutants were used to recover the apoptotic phenotype caused by αNAC depletion. Finally, the role of αNAC in TNF-related apoptosis-inducing ligand (TRAIL) treatment was investigated in vitro. We found that depletion of αNAC in multiple types of cancer cells induce typical apoptotic cell death. This anti-apoptotic function is mediated by the FADD/c-Jun N-terminal kinase pathway. Intact αNAC is required for the direct binding of FADD as well as its anti-apoptosis function. Either αNAC depletion or the deletion of the ubiquitin-associated domain of αNAC sensitizes L929 cancer cells to mTRAIL treatment. Our study revealed a αNAC anti-apoptotic function in multiple types of cancer cells and suggested its potential in cancer therapy.

An evaluation of a tailored intervention on village doctors use of electronic health records

BACKGROUND

To describe and evaluate the effectiveness of tailored intervention on village doctor's use of electronic health records (EHR) in rural community health services in less developed areas.

METHODS

Ten townships were selected. In each township, two similar health service station (CHSS) were chosen. One was randomly as allocated to the intervention group, the other to the control group. Over six monthly visits, a structured on-site intervention including education, supervision and technical support was provided to village doctors in the intervention group tailored to their needs. The Control group received no visits. A sample of 20 families from each CHSS was randomly chosen. An online evaluation of each family's EHR was conducted by the investigators at baseline and at the end of the 6 month intervention.

RESULTS

In the intervention group, the proportion of households with complete records increased: basic personal information from 2.6% to 32.5%, (Z = -15.099, P = 0.000) and health education records from 0.3% to 1.6% (Z = -4.459, P = 0.000). Similarly at baseline none of the 80 elders had her records. This increased in the intervention group to 16.4% recorded in part and 37.0% in full (Z = -7.480, P = 0.000). The proportion of complete health management records for children aged 1 to 2 years and 3 to 6 years increased from 28.6% and 33.3% to 66.7% and 74.2% respectively (the difference of children group 3 to 6 years of age was statistically significant, Z = -3.860, p = 0.000). The proportion of complete basic clinic records in the intervention group increased from 7.6% to 13.9% (Z = -3.252, P = 0.001). There were no significant differences in the control group.

CONCLUSIONS

The pilot study showed that a on-site education, supervision and technical support tailored to their needs was associated with improvements in village doctors use of EHR. This model is worthy of implementation in other rural areas.

Chronic disease prevalence and influencing factors among rural residents in Jiangxi, China

BACKGROUND

This study assessed the prevalence of chronic disease among rural residents in Jiangxi, China, analyzed influencing factors and provided scientific rationale for chronic disease prevention and control.

METHODS

Multi-stage stratified cluster random sampling was used to get a representative sample of rural residents in three counties across five time points from 2003 to 2012. Multivariate logistic regression and χ(2) analysis were performed to analyze the influencing factors.

RESULTS

The average prevalence of chronic disease across the five surveys was 7.9%. A declining trend in chronic disease prevalence from 9.1% in the baseline year to 6.9% in 2012 was observed. Multivariate logistic regression analysis showed that age, gender, occupation, education, marital status and employment were related to the prevalence of chronic disease.

CONCLUSION

The prevalence of chronic disease among rural residents in Jiangxi Province was lower than the national level, and declined over the course of the study. Strengthening health services and interventions for women, farmers, those who are divorced or widowed, the unemployed, and those with a low level of education or low income will help to improve the health status of the population.