A highly divergent human papillomavirus (HPV) strain, HPV-L55, was identified in fecal samples from children hospitalized with diarrhea in China. The L1 gene of HPV-L55 shares <75% identity with previously reported HPVs, indicating that this virus represents a novel type of HPV. Phylogenetic analysis classified this virus as a member of the gammapapillomaviruses.
In this study, we describe a novel porcine parechovirus-like virus (tentatively named PLV-CHN) from healthy piglets in China using 454 high-throughput sequencing. The complete genome of the virus comprises 6832 bp, encoding a predicted polyprotein of 2132 amino acids that is most similar to Ljungan virus (32% identity). A similar virus that belongs to a novel Picornaviridae genus, named swine pasivirus 1 (SPaV-1), was reported during the preparation of this paper. Sequence analysis revealed that PLV-CHN and SPaV1 shared 82% nucleotide identity and 89% amino acid identity. Further genomic and phylogenetic analyses suggested that both SPaV1 and PLV-CHN shared similar genomic characteristics and belong to the same novel Picornaviridae genus. A total of 36 (20.0%) fecal samples from 180 healthy piglets were positive for PLV-CHN by RT-PCR, while no fecal samples from 100 healthy children and 100 children with diarrhea, and no cerebrospinal fluid samples from 196 children with suspected viral encephalitis, was positive for the virus. However, Western blot and enzyme-linked immunosorbent assays using recombinant PLV-CHN VP1 polypeptide as an antigen showed a high seroprevalence of 63.5% in the healthy population. When grouped by age, the antibody-positivity rates showed that the majority of children under 12 years of age have been infected by the virus. It was suggested that PLV-CHN, SPaV1, or an as-yet-uncharacterized virus can infect humans early in life. Thus, investigation of the role of this novel virus is vital.
H19 is a paternally imprinted gene that has been shown to be highly expressed in the trophoblast tissue. Results from previous studies have initiated a debate as to whether noncoding RNA H19 acts as a tumor suppressor or as a tumor promotor in trophoblast tissue. In the present study, we developed lentiviral vectors expressing H19-specific small interfering RNA (siRNA) to specifically block the expression of H19 in the human choriocarcinoma cell line JAR. Using this approach, we investigated the impact of the H19 gene on the proliferation, invasion and apoptosis of JAR cells. Moreover, we examined the effect of H19 knockdown on the expression of insulin-like growth factor 2 (IGF2), hairy and enhancer of split homologue-1 (HES-1) and dual-specific phosphatase 5 (DUSP5) genes.
H19 knockdown inhibited apoptosis and proliferation of JAR cells, but had no significant impact on cell invasion. In addition, H19 knockdown resulted in significant upregulation of HES-1 and DUSP5 expression, but not IGF2 expression in JAR cells.
The finding that H19 downregulation could simultaneously inhibit proliferation and apoptosis of JAR cells highlights a putative dual function for H19 in choriocarcinoma and may explain the debate on whether H19 acts as a tumor suppressor or a tumor promotor in trophoblast tissue. Furthermore, upregulation of HES-1 and DUSP5 may mediate H19 downregulation-induced suppression of proliferation and apoptosis of JAR cells.
H19; JAR cells; Choriocarcinoma; HES-1; DUSP5; IGF2
Defensins are small cationic peptides that could be used as the potential substitute for antibiotics. However, there is no efficient method for producing defensins. In this study, we developed a new strategy to produce defensin in nitrate reductase (NR)-deficient C. ellipsoidea (nrm-4). We constructed a plant expression vector carrying mutated NP-1 gene (mNP-1), a mature α-defensin NP-1 gene from rabbit with an additional initiator codon in the 5′-terminus, in which the selection markers were NptII and NR genes. We transferred mNP-1 into nrm-4 using electroporation and obtained many transgenic lines with high efficiency under selection chemicals G418 and NaNO3. The mNP-1 was characterized using N-terminal sequencing after being isolated from transgenic lines. Excitingly, mNP-1 was produced at high levels (approximately 11.42 mg/l) even after 15 generations of continuous fermentation. In addition, mNP-1 had strong activity against Escherichia coli at 5 µg/ml. This research developed a new method for producing defensins using genetic engineering.
Esophageal squamous cell carcinoma (ESCC) is a prevalent and fatal cancer in China and other Asian countries. Epigenetic silencing of key tumor suppressor genes (TSGs) is critical to ESCC initiation and progression. Recently, many novel TSGs silenced by promoter methylation have been identified in ESCC, and these genes further serve as potential tumor markers for high-risk group stratification, early detection, and prognosis prediction. This review summarizes recent discoveries on aberrant promoter methylation of TSGs in ESCC, providing better understanding of the role of disrupted epigenetic regulation in tumorigenesis and insight into diagnostic and prognostic biomarkers for this malignancy.
Tumor suppressor gene; CpG island; promoter methylation; esophageal squamous cell carcinoma; tumor marker
Breast cancer is a complex disease driven by multiple factors including both genetic and epigenetic alterations. Recent studies revealed that abnormal gene expression induced by epigenetic changes, including aberrant promoter methylation and histone modification, plays a critical role in human breast Carcinogenesis. Silencing of tumor suppressor genes (TSGs) by promoter CpG methylation facilitates cells growth and survival advantages and further results in tumor initiation and progression, thus directly contributing to breast tumorigenesis. Usually, aberrant promoter methylation of TSGs, which can be reversed by pharmacological reagents, occurs at the early stage of tumorigenesis and therefore may serve as a potential tumor marker for early diagnosis and therapeutic targeting of breast cancer. In this review, we summarize the epigenetic changes of multiple TSGs involved in breast pathogenesis and their potential clinical applications as tumor markers for early detection and treatment of breast cancer.
Breast cancer; tumor suppressor gene; CpG; methylation; tumor marker
Soybean isoflavones are structurally similar to mammalian estrogens and therefore may act as estrogen agonists or antagonists. However, it has not been determined if they have any negative effects on reproductive parameters in male livestock. Therefore, the objective of this study was to evaluate the effects of soybean isoflavones on male reproduction using Chinese mini-pig boars as a model. Fifty Xiang boars were randomly divided into five groups and fed diets containing 0, 125, 250, or 500 ppm soybean isoflavones or 0.5 ppm diethylstilbestrol for 60 days.
Dietary supplementation with 250 ppm of soy isoflavones markedly increased the testis index (P < 0.05), fructose content (P < 0.05), and α-glycosidase content in testicular tissue (P < 0.01), as well as increased the number of viable germ cells (P < 0.01) and the level of Bcl-2 protein (P < 0.01). However, 500 ppm of soybean isoflavones significantly reduced both testis and epididymis indexes (P < 0.05) and lactate dehydrogenase levels (P < 0.01), as well as reduced serum LH and testosterone levels (P < 0.05). High levels of soybean isoflavones also increased malondialdehyde levels (P < 0.05), as well as increased the numbers of early and late apoptotic germ cells (P < 0.01) and the level of Bax proteins (P < 0.05) in the testis.
The results of this study indicate that consumption of soy isoflavones at dietary levels up to 250 ppm did not adversely affect reproductive parameters in Chinese mini-pig boars whereas higher levels of soy isoflavones may adversely affect male reproduction.
Soy isoflavones; Male reproductive function; Pigs
In mammals, hair cells do not undergo spontaneous regeneration when they are damaged and result in permanent hearing loss. Previous studies in cultured Organ of Corti dissected from neonatal animals have shown that both DAPT (r-secretase inhibitor in the Notch signal pathway) treatment and Atoh1 overexpression can induce supernumerary hair cells. The effects of simultaneous DAPT treatment and Atoh1 over expression in the cells of cultured Organ of Corti from neonatal rats are still obscure.
In this study, we set out to investigate the interaction of DAPT treatment and Atoh1 overexpression as well as culture time and the location of basilar fragment isolated form neonatal rat inner ear. Our results showed that DAPT treatment induced more hair cells in the apical turn, while Atoh1 overexpression induced more extra hair cells in the middle turn of the cultured Organ of Corti. When used together, their effects are additive but not synergistic. In addition, the induction of supernumerary hair cells by both DAPT and Atoh1 overexpression is dependent on the treatment time and the location of the cochlear tissue. Moreover, DAPT treatment causes dramatic changes in the orientation of the stereociliary bundles of hair cells, whereas Atoh1 overexpression didn't induce drastic change of the polarity of stereociliary bundles.
Taken together, these results suggest that DAPT treatment are much more potent in inducing supernumerary hair cells than Atoh1 overexpression and that the new hair cells mainly come from the trans-differentiation of supporting cells around hair cells. The orientation change of stereociliary bundle of hair cells may be attributed to the insertion of the newly formed hair cells. The immature hair bundles on the newly formed hair cells may also contribute to the overall chaos of the stereociliary bundle of the sensory epithelia.
To examine the validation and reliability of the distress thermometer (DT) recommended by National Comprehensive Cancer Network (NCCN) in Chinese cancer patients.
A total of 574 Chinese cancer patients from Beijing Cancer Hospital completed the detection of DT, the Hospital Anxiety and Depression Scale (HADS) and Symptom Checklist 90 (SCL-90), Receiver Operating Characteristic (ROC) curve and Area Under the Curve (AUC) were used to analyze the validation relative to HADS and SCL-90. The patients with DT≥4 and whose distress caused by emotional problems were interviewed with the MiNi International Neuro-psychiatric Interview (MINI) (Chinese Version 5.0). This version was used to analyze cancer patients’ psychological and Psychiatric symptoms during the cancer process; 3. Another 106 cancer patients in rehabilitation stage and stable condition were asked to fill in DT two times, at the base time and after 7-10 days.
Data of ROC indicates that a DT cutoff score of 4 yielded AUC of 0.80 with a optimal sensitivity (0.80) and specificity (0.70) relative to HADS, and AUC of 0.83 with the greatest sensitivity (0.87) and specificity (0.72) against SCL-90. The DT also has acceptable test-retest reliability (r=0.800, P=0.000); According to the interview results, the most common psychiatric problems cancer patients have adjustment disorder, depression, and anxiety.
The data suggest that DT has acceptable overall accuracy and reliability as a screening tool for testing distress severity and specific problems causing distress in Chinese cancer patients. It is worth being used in oncology clinic, the rapid screening and interview could help caregivers to identify psychological and psychiatric problems of cancer patients and provide useful information for further treatment.
Validation; Reliability; Cancer patients; Distress thermometer
This article explores the associations between medical care providers’ attitudes toward patients living with HIV (PLH) and the service satisfaction reported from general patients. Data were collected from 40 county-level hospitals in China, including 1,760 service providers and 1,000 patients receiving medical services from the hospitals. Provider and patient assessments were conducted by self-administered questionnaires and face-to-face interviews, respectively. Random-effect regression models were used to examine relationships between the providers’ avoidance attitudes and patient satisfaction at the hospital level while taking into account variations in demographics and professional experience within each hospital. Service providers’ avoidance attitudes towards PLH were negatively associated with general patients’ satisfaction with service providers at the hospital level. The relationship was strong and significant whether or not adjustments were made for background characteristics. Medical care providers’ stigmatizing attitudes toward PLH could be a reflection of the providers’ general outlook with all patients. This study underscores a broader focus for HIV-related stigma reduction interventions in medical settings at both individual and institutional levels, targeting attitudes toward both HIV/AIDS patients and the general patient population.
HIV; stigma; provider; patient satisfaction
Fluorescent biosensors based on environmentally sensitive dyes enable visualization and quantification of endogenous protein activation within living cells. Merocyanine dyes are especially useful for live cell imaging applications as they are extraordinarily bright, have long wavelengths of excitation and emission, and can exhibit readily detectable fluorescence changes in response to environment. We sought to systematically examine the effects of structural features on key photophysical properties, including dye brightness, environmental responsiveness, and photostability, through the synthesis of a library of 25 merocyanine dyes, derived from combinatorial reaction of 5 donor and 5 acceptor heterocycles. Four of these dyes showed optimal properties for specific imaging applications and were subsequently prepared with reactive side chains and enhanced aqueous solubility using a one-pot synthetic method. The new dyes were then applied within a biosensor design for Cdc42 activation, where dye mero60 showed a remarkable 1470% increase in fluorescence intensity on binding activated Cdc42 in vitro. The dye-based biosensors were used to report activation of endogenous Cdc42 in living cells.
Caspase-3 and caspase-7 are two key effector caspases that play important roles in apoptotic pathways that maintain normal tissue and organ development and homeostasis. However, little is known about the sequence, structure, activity, and function of effector caspases upon apoptosis in mollusks, especially marine bivalves. In this study, we investigated the possible roles of two executioner caspases in the regulation of apoptosis in the Pacific oyster Crassostrea gigas. A full-length capase-3–like gene named Cgcaspase-3 was cloned from C.gigas cDNA, encoding a predicted protein containing caspase family p20 and p10 domain profiles and a conserved caspase active site motif. Phylogenetic analysis demonstrated that both Cgcaspase-3 and Cgcaspase-1 may function as effector caspases clustered in the invertebrate branch. Although the sequence identities between the two caspases was low, both enzymes possessed executioner caspase activity and were capable of inducing cell death. These results suggested that Cgcaspase-3 and Cgcaspase-1 were two effector caspases in C. gigas. We also observed that nucleus-localized Cgcaspase-3, may function as a caspase-3–like protein and cytoplasm-localized Cgcaspase-1 may function as a caspase-7–like protein. Both Cgcaspase-3 and Cgcaspase-1 mRNA expression increased after larvae settled on the substratum, suggesting that both caspases acted in several tissues or organs that degenerated after oyster larvae settlement. The highest caspase expression levels were observed in the gills indicating that both effector caspases were likely involved in immune or metabolic processes in C. gigas.
The effects of a community popular opinion leader (CPOL) intervention were examined among market vendors in a city on the eastern coast of China. Employees of 40 food markets were enrolled in a study that provided HIV-related education and tests, and treatment for sexually transmitted diseases (STDs). Twenty markets were randomly assigned to a CPOL intervention (N = 1695) and 20 markets to a control condition (N = 1616). Market employees in the intervention condition reported positive attitudes regarding STD/HIV prevention and more frequent discussions about safe sex than those in the control condition. Compared to baseline, the prevalence of unprotected sexual acts and new STDs were significantly lower within each study condition 24 months later. Although the CPOL intervention achieved its goal of shifting attitudes within food markets, the gains did not lead to the expected behavioral and biological outcomes.
Stroke is a major neurovascular disorder threatening human life and health. Very limited clinical treatments are currently available for stroke patients. Stem cell transplantation has shown promising potential as a regenerative treatment after ischemic stroke. The present investigation explores a new concept of mobilizing endogenous stem cells/progenitor cells from the bone marrow using a parathyroid hormone (PTH) therapy after ischemic stroke in adult mice. PTH 1-34 (80 µg/kg, i.p.) was administered 1 hour after focal ischemia and then daily for 6 consecutive days. After 6 days of PTH treatment, there was a significant increase in bone marrow derived CD-34/Fetal liver kinase-1 (Flk-1) positive endothelial progenitor cells (EPCs) in the peripheral blood. PTH treatment significantly increased the expression of trophic/regenerative factors including VEGF, SDF-1, BDNF and Tie-1 in the brain peri-infarct region. Angiogenesis, assessed by co-labeled Glut-1 and BrdU vessels, was significantly increased in PTH-treated ischemic brain compared to vehicle controls. PTH treatment also promoted neuroblast migration from the subventricular zone (SVZ) and increased the number of newly formed neurons in the peri-infarct cortex. PTH-treated mice showed significantly better sensorimotor functional recovery compared to stroke controls. Our data suggests that PTH therapy improves endogenous repair mechanisms after ischemic stroke with functional benefits. Mobilizing endogenous bone marrow-derived stem cells/progenitor cells using PTH and other mobilizers appears an effective and feasible regenerative treatment after ischemic stroke.
Some aspects of the neighborhood built environment may influence residents’ physical activity, which in turn, affects their health. This study aimed to develop an urban built environment evaluation tool and conduct necessary reliability and validity tests.
A 41-item urban built environment scan tool was developed to objectively assess the neighborhood built environment features related to physical activity. Six neighborhoods in Hangzhou were selected from three types of administrative planning units. A pair of auditors independently assessed all of the 205 street segments at the same time. Half of the segments (n = 104) were audited twice by the same auditor after a two-week time interval. Inter-rater reliability was assessed by comparing the audits of paired observers, while intra-rater reliability was evaluated by comparing an auditor’s repeated assessments of the same segments. The construct validity was tested using factor analysis.
The inter-rater reliability for most items was above 0.8. The intra-rater reliability for most items was above 0.4, and was lower than corresponding inter-rater reliability. Six factors were extracted by factor analysis and the factor loading matrix showed good construct validity.
The CUBEST is a reliable and valid instrument that can be used to assess the physical activity-related built environment in Hangzhou, and potentially other cities in China.
Environmental scan; Physical activity; Reliability; Validity
During the last few decades, the prevalence of allergic skin diseases, asthma and rhinitis, has increased worldwide. Introduction of environmental chemicals with aggravation effects may play a part in this increase. The artificial chemical product dibutyl phthalate (DBP) is used in many products used in daily life. Dermal exposure to DBP is a common (but easily neglected) exposure pattern.
In this study, we examined the aggravation effect of long-term dermal exposure to DBP in a T-helper type 2 (Th2) model of contact hypersensitivity (CHS) in mice, and sought the potential molecular mechanisms. Experimental tests were conducted after 40-day dermal exposure to saline or three concentrations of DBP and subsequent three times of sensitization with 0.5% fluorescein isothiocyanate (FITC) or vehicle. The results of immunological and inflammatory biomarkers (total-immunoglobulin (Ig)E and Th cytokines) as well as histopathological examination and measurement of ear swelling supported the notion that high doses of DBP may promote and aggravate atopic dermatitis. Increased expression of thymic stromal lymphopoietin (TSLP) in this mouse model suggested that TSLP might be one of the molecular mechanisms of the aggravation effect induced by DBP.
Together, these results indicated that long-term dermal exposure to types of environmental toxins such as phthalates may endow an atopic predisposition in animals or humans. In addition, the high expression of TSLP in the mouse model demonstrated that TSLP might have an important role in the aggravation effect. This result could help to provide effective prevention strategies against atopic diseases such as atopic dermatitis (AD).
This study examines the preliminary outcomes of an intervention targeting service providers in methadone maintenance therapy clinics in China. The intervention effects on both service providers and clients are reported.
The MMT CARE intervention pilot was developed and implemented collaboratively with local health educators. After three group intervention sessions, trained providers in intervention clinics delivered two individual motivational interviewing sessions with their clients.
Six clinics in Sichuan, China, were randomized to either the MMT CARE intervention condition or a standard care condition.
A total of 41 providers and 179 clients were sampled from the six clinics.
At baseline and 3-, 6-, and 9-month assessments, providers completed self-administrated paper/pencil questionnaires regarding provider-client interaction, methadone maintenance therapy knowledge, perceived job-related stigma, and clinic support. Clients completed a face-to-face survey about their concurrent drug use and drug avoidance self-efficacy. Mixed-effects regression models with clinic-level random effect were used to assess the intervention effects.
Significant intervention effects for providers were found in improved methadone maintenance therapy knowledge, provider-client interaction, and perceived clinic support. For clients, better improvements in drug avoidance self-efficacy and reduced concurrent drug use were observed for the intervention compared to the standard care group.
The methadone maintenance therapy CARE intervention targeting providers in methadone maintenance clinics can improve providers’ treatment knowledge and their interaction with clients. The intervention can also reduce clients’ drug using behavior through motivational interviewing sessions conducted by trained providers.
Methadone maintenance therapy; providers; intervention pilot; China
The objective of the intervention was to reduce service providers’ stigmatizing attitudes and behaviors toward people living with HIV.
The randomized controlled trial was conducted in 40 county-level hospitals in 2 provinces of China between October 2008 and February 2010. Forty-four service providers were randomly selected from each hospital, yielding a total of 1760 study participants. We randomized the hospitals to either an intervention condition or a control condition. In the intervention hospitals, about 15% of the popular opinion leaders were identified and trained to disseminate stigma reduction messages.
We observed significant improvements for the intervention group in reducing prejudicial attitudes (P < .001), reducing avoidance intent towards people living with HIV (P < .001), and increasing institutional support in the hospitals (P = .003) at 6 months after controlling for service providers’ background factors and clinic-level characteristics. The intervention effects were sustained and strengthened at 12 months.
The intervention reduced stigmatizing attitudes and behaviors among service providers. It has the potential to be integrated into the health care systems in China and other countries.
Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is increasingly used for breast cancer diagnosis as supplementary to conventional imaging techniques. Combining of diffusion-weighted imaging (DWI) of morphology and kinetic features from DCE-MRI to improve the discrimination power of malignant from benign breast masses is rarely reported.
Materials and Methods
The study comprised of 234 female patients with 85 benign and 149 malignant lesions. Four distinct groups of features, coupling with pathological tests, were estimated to comprehensively characterize the pictorial properties of each lesion, which was obtained by a semi-automated segmentation method. Classical machine learning scheme including feature subset selection and various classification schemes were employed to build prognostic model, which served as a foundation for evaluating the combined effects of the multi-sided features for predicting of the types of lesions. Various measurements including cross validation and receiver operating characteristics were used to quantify the diagnostic performances of each feature as well as their combination.
Seven features were all found to be statistically different between the malignant and the benign groups and their combination has achieved the highest classification accuracy. The seven features include one pathological variable of age, one morphological variable of slope, three texture features of entropy, inverse difference and information correlation, one kinetic feature of SER and one DWI feature of apparent diffusion coefficient (ADC). Together with the selected diagnostic features, various classical classification schemes were used to test their discrimination power through cross validation scheme. The averaged measurements of sensitivity, specificity, AUC and accuracy are 0.85, 0.89, 90.9% and 0.93, respectively.
Multi-sided variables which characterize the morphological, kinetic, pathological properties and DWI measurement of ADC can dramatically improve the discriminatory power of breast lesions.
Infantile hemangioma (IH), which is the most common tumor in infants, is a benign vascular neoplasm resulting from the abnormal proliferation of endothelial cells and pericytes. For nearly a century, researchers have noted that IH exhibits diverse and often dramatic clinical behaviors. On the one hand, most lesions pose no threat or potential for complication and resolve spontaneously without concern in most children with IH. On the other hand, approximately 10% of IHs are destructive, disfiguring and even vision- or life-threatening. Recent studies have provided some insight into the pathogenesis of these vascular tumors, leading to a better understanding of the biological features of IH and, in particular, indicating that during hemangioma neovascularization, two main pathogenic mechanisms prevail, angiogenesis and vasculogenesis. Both mechanisms have been linked to alterations in several important cellular signaling pathways. These pathways are of interest from a therapeutic perspective because targeting them may help to reverse, delay or prevent hemangioma neovascularization. In this review, we explore some of the major pathways implicated in IH, including the VEGF/VEGFR, Notch, β-adrenergic, Tie2/angiopoietins, PI3K/AKT/mTOR, HIF-α-mediated and PDGF/PDGF-R-β pathways. We focus on the role of these pathways in the pathogenesis of IH, how they are altered and the consequences of these abnormalities. In addition, we review the latest preclinical and clinical data on the rationally designed targeted agents that are now being directed against some of these pathways.
Infantile hemangioma; Neovascularization; Angiogenesis; Vasculogenesis
It has become increasingly clear that the current taxonomy of clinical phenotypes is mixed with molecular heterogeneity, which potentially affects the treatment effect for involved patients. Defining the hidden molecular-distinct diseases using modern large-scale genomic approaches is therefore useful for refining clinical practice and improving intervention strategies. Given that microRNA expression profiling has provided a powerful way to dissect hidden genetic heterogeneity for complex diseases, the aim of the study was to develop a bioinformatics approach that identifies microRNA features leading to the hidden subtyping of complex clinical phenotypes. The basic strategy of the proposed method was to identify optimal miRNA clusters by iteratively partitioning the sample and feature space using the two-ways super-paramagnetic clustering technique. We evaluated the obtained optimal miRNA cluster by determining the consistency of co-expression and the chromosome location among the within-cluster microRNAs, and concluded that the optimal miRNA cluster could lead to a natural partition of disease samples. We applied the proposed method to a publicly available microarray dataset of breast cancer patients that have notoriously heterogeneous phenotypes. We obtained a feature subset of 13 microRNAs that could classify the 71 breast cancer patients into five subtypes with significantly different five-year overall survival rates (45%, 82.4%, 70.6%, 100% and 60% respectively; p = 0.008). By building a multivariate Cox proportional-hazards prediction model for the feature subset, we identified has-miR-146b as one of the most significant predictor (p = 0.045; hazard ratios = 0.39). The proposed algorithm is a promising computational strategy for dissecting hidden genetic heterogeneity for complex diseases, and will be of value for improving cancer diagnosis and treatment.
Dihydroceramide desaturase 1 (DES) is the enzyme responsible for converting dihydroceramide into ceramide in the de novo sphingolipid biosynthesis pathway. Dihydroceramide can inhibit ceramide channel formation to interfere with apoptosis. We have shown that following ceramide synthase knockdown, photodynamic therapy (PDT), a cancer treatment modality, is associated with decreased levels of ceramides and dihydroceramides in cells that are resistant to apoptosis.
Here we investigated the effect of DES knockdown on the sphingolipid profile and apoptosis in human head and neck squamous carcinoma cells after PDT with the silicon phthalocyanine Pc 4.
Materials and Methods
Following siRNA transfection and PDT treatment, quantitative real-time polymerase chain reaction for quantification of DES mRNA, immunoblotting for protein expression, mass spectrometry for sphingolipid analysis, spectrofluorometry for caspase 3-like (DEVDase) activity, flow cytometry for apoptosis detection, and trypan blue assay for cell viability evaluation, were performed.
Down-regulation of DES led to a substantial increase in levels of dihydroceramides without affecting ceramide levels. PDT-induced accumulation of individual dihydroceramides and global ceramides was increased by DES knockdown. Concomitantly, mitochondrial depolarization, DEVDase activation, late-apoptosis and cell death were attenuated by DES knockdown. Early apoptosis, however, was enhanced.
Our findings support the following: (i) dihydroceramide reduces pro-apoptotic effects of ceramide; (ii) cells adapt to DES knockdown to become more sensitive to ceramide and early-apoptosis; (iii) DES is a potential molecular target for regulating apoptotic resistance to PDT.
Apoptosis; ceramide; dihydroceramide desaturase; dihydroceramide; PDT; sphingolipids; UM-SCC-22A cells; HNSCC
Increased excavation of dinosaurs from China over the last two decades has enriched the record of Asian titanosauriform sauropods. However, the relationships of these sauropods remain contentious, and hinges on a few well-preserved taxa, such as Euhelopus zdanskyi. Here we describe a new sauropod, Yongjinglong datangi gen. nov. et sp. nov., from the Lower Cretaceous Hekou Group in the Lanzhou Basin of Gansu Province, northwestern China. Yongjinglong datangi is characterized by the following unique combination of characters, including seven autapomorphies: long-crowned, spoon-shaped premaxillary tooth; axially elongate parapophyses on the cervical vertebra; very deep lateral pneumatic foramina on the lateral surfaces of the cervical and cranial dorsal vertebral centra; low, unbifurcated neural spine fused with the postzygapophyses to form a cranially-pointing, triangular plate in a middle dorsal vertebra; an “XI”-shaped configuration of the laminae on the arches of the middle dorsal vertebrae; a very long scapular blade with straight cranial and caudal edges; and a tall, deep groove on the lateral surface of the distal shaft of the radius. The new specimen shares several features with other sauropods: a pronounced M. triceps longus tubercle on the scapula and ventrolaterally elongated parapophyses in its cervical vertebra as in Euhelopodidae. Based on phylogenetic analyses Yongjinglong datangi is highly derived within Titanosauria, which suggests either a remarkable convergence with more basal titanosauriform sauropods in the Early Cretaceous or a retention of plesiomorphic features that were lost in other titanosaurians. The morphology and remarkable length of the scapulocoracoid reveal an unusual relationship between the shoulder and the middle trunk: the scapulocoracoid spans over half of the length of the trunk. The medial, notch-shaped coracoid foramen and the partially fused scapulocoracoid synostosis suggest that the specimen is a subadult individual. This specimen sheds new light on the diversity of Early Cretaceous Titanosauriformes in China.
Both anterior cervical discectomy with fusion (ACDF) and anterior cervical corpectomy with fusion (ACCF) are used to treat cervical spondylotic myelopathy (CSM), however, there is considerable controversy as to whether ACDF or ACCF is the optimal treatment for this condition. To compare the clinical outcomes, complications, and surgical trauma between ACDF and ACCF for the treatment of CSM, we conducted a meta-analysis.
We conducted a comprehensive search in MEDLINE, EMBASE, PubMed, Google Scholar and Cochrane databases, searching for relevant controlled trials up to July 2013 that compared ACDF and ACCF for the treatment of CSM. We performed title and abstract screening and full-text screening independently and in duplicate. A random effects model was used for heterogeneous data; otherwise, a fixed effect model was used to pool data, using mean difference (MD) for continuous outcomes and odds ratio (OR) for dichotomous outcomes.
Of 2157 citations examined, 15 articles representing 1372 participants were eligible. Overall, there were significant differences between the two treatment groups for hospital stay (M = −5.60, 95% CI = −7.09 to −4.11), blood loss (MD = −151.35, 95% CI = −253.22 to −49.48), complications (OR = 0.50, 95% CI = 0.35 to 0.73) and increased lordosis of C2–C7 (MD = 3.70, 95% CI = 0.96 to 6.45) and fusion segments angles (MD = 3.38, 95% CI = 2.54 to 4.22). However, there were no significant differences in the operation time (MD = −9.34, 95% CI = −42.99 to 24.31), JOA (MD = 0.24, 95% CI = −0.10 to 0.57), VAS (MD = −0.06, 95% CI = −0.81 to 0.70), NDI (MD = −1.37, 95% CI = −3.17 to 0.43), Odom criteria (OR = 0.88, 95% CI = 0.60 to 1.30) or fusion rate (OR = 1.17, 95% CI = 0.34 to 4.11).
Based on this meta-analysis, although complications and increased lordosis are significantly better in the ACDF group, there is no strong evidence to support the routine use of ACDF over ACCF in CSM.
The striatum receives serotonin (5-hydroxytryptamine, 5-HT) innervation and expresses 5-HT2A receptors (5-HT2ARs) and other 5-HT receptors, raising the possibility that the striatal 5-HT system may undergo adaptive changes after chronic severe dopamine (DA) loss and contribute to the function and dysfunction of the striatum. Here we show that in transcription factor Pitx3 gene mutant mice with a selective, severe DA loss in the dorsal striatum mimicking the DA denervation in late Parkinson’s disease (PD), both the 5-HT innervation and the 5-HT2AR mRNA expression were increased in the dorsal striatum. Functionally, while having no detectable motor effect in wild type mice, the 5-HT2R agonist 2,5-dimethoxy-4-iodoamphetamine increased both the baseline and L-dopa-induced normal ambulatory and dyskinetic movements in Pitx3 mutant mice, whereas the selective 5-HT2AR blocker volinanserin had the opposite effects. These results demonstrate that Pitx3 mutant mice are a convenient and valid mouse model to study the compensatory 5-HT upregulation following the loss of the nigrostriatal DA projection and that the upregulated 5-HT2AR function in the DA deficient dorsal striatum may enhance both normal and dyskinetic movements.
L-3,4-dihydroxyphenylalanine (L-dopa); 5-HT2A receptor; basal ganglia; dopamine; dyskinesia; Parkinson’s disease; qRT-PCR; striatum