PGCLCs of human 45,XO reveal pathogenetic pathways of neurocognitive and psychosocial disorders

Background

Neurocognitive disorders and psychosocial difficulties are common in patients with Turner syndrome and multiple neurodegenerative diseases, yet there is no effective cure. Human primordial germ cells (hPGCs) are pluripotent germline stem cells in early embryo, which pass genetic information from one generation to the next, whereas all somatic cells will die along with the end of life. However, it is not known whether patient hPGCs with Turner syndrome contain information of neurocognitive and psychosocial illness.

Results

In this report, we used a high-density of culture system of embryoids derived from iPSCs of a patient with Turner syndrome to ask how pathogenetic pathways are associated with onset of neurocognitive and psychosocial disorders. The hPGC-Like Cells (hPGCLCs) were in vitro specified from iPSCs of 45,XO, 46,XX and 46,XY by the high-density induction of embryoids. Amazingly, we found that the specification process of the hPGCLCs in 45,XO, compared to those in 46,XX and 46,XY, enriched several common pathogenetic pathways regulating neurocognitive and psychosocial disorders, that shared among multiple neurodegenerative diseases and Turner syndrome. The downregulated chemical synaptic transmission pathways, including glutamatergic, GABAergic, and nicotine cholinergic synapses, indicated synaptic dysfunctions, while upregulated pathways that were associated with imbalance of mitochondrial respiratory chain complexes and apoptosis, may contribute to neuronal dysfunctions. Notably, downregulation of three types of ubiquitin ligases E1-E2-E3 and lysosome-associated sulfatases and RAB9A, owing to haploinsufficiency and parental preference of the X chromosome expression, indicated that two pathways of cellular degradation, lysosome and ubiquitin–proteasome, were impaired in the specification process of 45,XO hPGCLCs. This would lead to accumulation of undesired proteins and aggregates, which is a typically pathological hallmark in neurodegenerative diseases.

Conclusions

Our data suggest that the specification process of the hPGCLCs in 45,XO, compared to those in 46,XX and 46,XY, enriched pathogenetic pathways that are associated with the onset of neurocognitive and psychosocial disorders.

Germline stem cells in human

The germline cells are essential for the propagation of human beings, thus essential for the survival of mankind. The germline stem cells, as a unique cell type, generate various states of germ stem cells and then differentiate into specialized cells, spermatozoa and ova, for producing offspring, while self-renew to generate more stem cells. Abnormal development of germline stem cells often causes severe diseases in humans, including infertility and cancer. Primordial germ cells (PGCs) first emerge during early embryonic development, migrate into the gentile ridge, and then join in the formation of gonads. In males, they differentiate into spermatogonial stem cells, which give rise to spermatozoa via meiosis from the onset of puberty, while in females, the female germline stem cells (FGSCs) retain stemness in the ovary and initiate meiosis to generate oocytes. Primordial germ cell-like cells (PGCLCs) can be induced in vitro from embryonic stem cells or induced pluripotent stem cells. In this review, we focus on current advances in these embryonic and adult germline stem cells, and the induced PGCLCs in humans, provide an overview of molecular mechanisms underlying the development and differentiation of the germline stem cells and outline their physiological functions, pathological implications, and clinical applications.

Srag Regulates Autophagy via Integrating into a Preexisting Autophagy Pathway in Testis

Spermatogenesis is an essential process for producing sperm cells. Reproductive strategy is successfully evolved for a species to adapt to a certain ecological system. However, roles of newly evolved genes in testis autophagy remain unclear. In this study, we found that a newly evolved gene srag (Sox9-regulated autophagy gene) plays an important role in promoting autophagy in testis in the lineage of the teleost Monopterus albus. The gene integrated into an interaction network through a two-way strategy of evolution, via Sox9-binding in its promoter and interaction with Becn1 in the coding region. Its promoter region evolved a cis element for binding of Sox9, a transcription factor for male sex determination. Both in vitro and in vivo analyses demonstrated that transcription factor Sox9 could bind to and activate the srag promoter. Its coding region acquired ability to interact with key autophagy initiation factor Becn1 via the conserved C-terminal, indicating that srag integrated into preexisting autophagy network. Moreover, we determined that Srag enhanced autophagy by interacting with Becn1. Notably, srag transgenic zebrafish revealed that Srag exerted the same function by enhancing autophagy through the Srag–Becn1 pathway. Thus, the new gene srag regulated autophagy in testis by integrated into preexisting autophagy network.

Whole genome-wide chromosome fusion and new gene birth in the Monopterus albus genome

Background

Teleost fishes account for over half of extant vertebrate species. A core question in biology is how genomic changes drive phenotypic diversity that relates to the origin of teleost fishes.

Results

Here, we used comparative genomic analyses with chromosome assemblies of diverse lineages of vertebrates and reconstructed an ancestral vertebrate genome, which revealed phylogenomic trajectories in vertebrates. We found that the whole-genome-wide chromosome fission/fusions took place in the Monopterus albus lineage after the 3-round whole-genome duplication. Four times of genomic fission/fusions events resulted in the whole genome-wide chromosome fusions in the genomic history of the lineage. In addition, abundant recently evolved new genes for reproduction emerged in the Monopterus albus after separated from medaka. Notably, we described evolutionary trajectories of conserved blocks related to sex determination genes in teleosts.

Conclusions

These data pave the way for a better understanding of genomic evolution in extant teleosts.

Gene essentiality of Tubgcp4: dosage effect and autophagy regulation in retinal photoreceptors

Photoreceptor degeneration and damages often lead to blindness, and the underlying molecular mechanisms are largely unknown. There is also a lot of missing information for establishing the role of macroautophagy/autophagy in the retinopathy. We recently generated knockout mouse lines of the essential gene Tubgcp4 (tubulin, gamma complex associated protein 4) and revealed an interplay between essential genes and autophagy regulation. Complete knockout of Tubgcp4 in mice results in early embryonic lethality due to abnormal spindle assembly, whereas heterozygotes are viable through dosage compensation from one wild-type allele, suggesting a dosage effect of the essential gene. However, haploinsufficiency of TUBGCP4 impairs assembly of TUBG/γ-tubulin ring complexes and disturbs autophagy homeostasis of the retina, with pathological phenotypes of photoreceptor degeneration and a decrease of electroretinography responses. TUBGCP4 can inhibit autophagy by competing with ATG3 to interact with ATG7, thus interfering with lipidation of LC3B. Taken together, these findings demonstrate dosage effect of the essential gene Tubgcp4 for viability of mutant mice, and suggest key roles of TUBGCP4 in embryo development and retinal homeostasis by autophagy regulation. Abbreviations: ATG3: autophagy related 3; ATG7: autophagy related 7; CRISPR: clustered regularly interspaced short palindromic repeats; ERG: electroretinography; HCQ: hydroxychloroquine; LC3B: microtubule-associated protein 1 light chain 3 beta; NFE2L2: nuclear factor, erythroid 2 like 2; ONL: outer nuclear layer; PPARGC1A: peroxisome proliferator-activated receptor gamma coactivator-1 alpha; RB1CC1: RB1 inducible coiled-coil 1; SQSTM1: sequestosome 1; TUBGCP: tubulin, gamma complex associated protein; TUBGRC/γ: TuRCs gamma-tubulin ring complexes.

The small GTPase RAB37 functions as an organizer for autophagosome biogenesis

Macroautophagy/autophagy is a catabolic process that is essential for cellular homeostasis. How autophagosomal vesicle forms in a spatio-temporally regulated manner remains elusive. Our recent study revealed that small GTPase, RAB37 (RAB37, member RAS oncogene family), functions as a key organizer of autophagosomal membrane biogenesis. RAB37 interacts with ATG5 (autophagy related 5) and promotes autophagosome formation by modulating ATG12-ATG5-ATG16L1 complex assembly. These findings provide new insights into autophagy regulation.

Isolation and characterization of string-forming female germline stem cells from ovaries of neonatal mice

Germline stem cells are essential in the generation of both male and female gametes. In mammals, the male testis produces sperm throughout the entire lifetime, facilitated by testicular germline stem cells. Oocyte renewal ceases in postnatal or adult life in mammalian females, suggesting that germline stem cells are absent from the mammalian ovary. However, studies in mice, rats, and humans have recently provided evidence for ovarian female germline stem cells (FGSCs). A better understanding of the role of FGSCs in ovaries could help improve fertility treatments. Here, we developed a rapid and efficient method for isolating FGSCs from ovaries of neonatal mice. Notably, our FGSC isolation method could efficiently isolate on average 15 cell "strings" per ovary from mice at 1-3 days postpartum. FGSCs isolated from neonatal mice displayed the string-forming cell configuration at mitosis (i.e. a "stringing" FGSC (sFGSC) phenotype) and a disperse phenotype in postnatal mice. We also found that sFGSCs undergo vigorous mitosis especially at 1-3 days postpartum. After cell division, the sFGSC membranes tended to be connected to form sFGSCs. Moreover, F-actin filaments exhibited a cell-cortex distribution in sFGSCs, and E-cadherin converged in cell-cell connection regions, resulting in the string-forming morphology. Our new method provides a platform for isolating FGSCs from the neonatal ovary, and our findings indicate that FGCSs exhibit string-forming features in neonatal mice. The sFGSCs represent a valuable resource for analysis of ovary function and an in vitro model for future clinical use to address ovarian dysfunction.

Human β-defensin-3 induces IL-8 release and apoptosis in airway smooth muscle cells

BACKGROUND

Human airway smooth muscle cells (ASMCs) may have a pro-inflammatory role through the release of inflammatory mediators. Increasing evidence indicates that human β-defensins (HBDs) are related to pathogenesis of asthma.

OBJECTIVES

To examine the plasma level of HBD-1, HBD-2 and HBD-3 in asthmatic patients and the expression of their mouse orthologues in the lung tissue of a mouse model of chronic severe asthma. Further to investigate the effect of HBD-3 on the release of the pro-inflammatory cytokine IL-8 and to explore the mechanisms.

METHODS

The plasma levels of HBD-1, HBD-2 and HBD-3 from 34 healthy controls and 25 asthmatic patients were determined by ELISA. The expression of mouse β-defensins MBD-1, MBD-3 and MBD-14 in the lung tissue of asthmatic mice was detected by Western blot. The ASMCs were cultured with HBD-3 for 24 hour, and then the supernatant level of IL-8 was evaluated by ELISA and the cell viability was examined by WST-1 assay. The signalling pathway was investigated with blocking antibodies or pharmacological inhibitors.

RESULTS

The plasma levels of HBD-1 and HBD-3 were elevated in asthmatic patients, and the expression of MBD-14, the mouse orthologue for HBD-3, was increased in asthmatic mice. HBD-3-induced IL-8 production in a CCR6 receptor-specific manner and was dependent on multiple signalling pathways. Moreover, HBD-3-induced cell apoptosis concurrently, which was dependent on the ERK1/2 MAPK pathway. Mitochondrial ROS regulated both HBD-3-induced IL-8 production and cell apoptosis.

CONCLUSIONS AND CLINICAL RELEVANCE

These observations provide clear evidence of an important new mechanism for the promotion of airway inflammation and tissue remodelling with potential relevance for the treatment of asthma.

Acute cholecystitis associated with infection of Enterobacteriaceae from gut microbiota

Acute cholecystitis (AC) is one of the most common surgical diseases. Bacterial infection accounts for 50% to 85% of the disease's onset. Since there is a close relationship between the biliary system and the gut, the aims of this study were to characterize and determine the influence of gut microbiota on AC, to detect the pathogenic microorganism in the biliary system, and to explore the relationship between the gut and bile microbiota of patients with AC. A total of 185 713 high-quality sequence reads were generated from the faecal samples of 15 patients and 13 healthy controls by 16S rRNA gene pyrosequencing. Patients' samples were significantly enriched in Akkermansia, Enterobacter and Escherichia/Shigella group. The healthy controls, however, showed significant enrichment of Clostridiales, Coprococcus, Coprobacillaceae, Paraprevotella, Turicibacter and TM7-3 in their faecal samples. Escherichia coli was the main biliary pathogenic microorganism, among others such as Klebsiella spp., Clostridium perfringens, Citrobacter freundii and Enterobacter cloacae in the bile of the patients. Additionally, the amount of bile endotoxin significantly correlated with the number of Enterobacteriaceae, especially E. coli. Our data indicate that Enterobacteriaceae might play essential role in the pathogenesis and/or progress of AC. This was verified in an in vivo model using a pathogenic E. coli isolated from one of the patients in guinea pigs and observed marked gallbladder inflammation and morphologic changes. This study thus provides insight which could be useful for the prevention, diagnosis and treatment of AC and related diseases by controlling the growth of Enterobacteriaceae to alleviate the infection.

Geometrical differences in target volumes based on 18F-fluorodeoxyglucose positron emission tomography/computed tomography and four-dimensional computed tomography maximum intensity projection images of primary thoracic esophageal cancer

The objective of the study was to compare geometrical differences of target volumes based on four-dimensional computed tomography (4DCT) maximum intensity projection (MIP) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) images of primary thoracic esophageal cancer for radiation treatment. Twenty-one patients with thoracic esophageal cancer sequentially underwent contrast-enhanced three-dimensional computed tomography (3DCT), 4DCT, and 18F-FDG PET/CT thoracic simulation scans during normal free breathing. The internal gross target volume defined as IGTVMIP was obtained by contouring on MIP images. The gross target volumes based on PET/CT images (GTVPET ) were determined with nine different standardized uptake value (SUV) thresholds and manual contouring: SUV≥2.0, 2.5, 3.0, 3.5 (SUVn); ≥20%, 25%, 30%, 35%, 40% of the maximum (percentages of SUVmax, SUVn%). The differences in volume ratio (VR), conformity index (CI), and degree of inclusion (DI) between IGTVMIP and GTVPET were investigated. The mean centroid distance between GTVPET and IGTVMIP ranged from 4.98 mm to 6.53 mm. The VR ranged from 0.37 to 1.34, being significantly (P<0.05) closest to 1 at SUV2.5 (0.94), SUV20% (1.07), or manual contouring (1.10). The mean CI ranged from 0.34 to 0.58, being significantly closest to 1 (P<0.05) at SUV2.0 (0.55), SUV2.5 (0.56), SUV20% (0.56), SUV25% (0.53), or manual contouring (0.58). The mean DI of GTVPET in IGTVMIP ranged from 0.61 to 0.91, and the mean DI of IGTVMIP in GTVPET ranged from 0.34 to 0.86. The SUV threshold setting of SUV2.5, SUV20% or manual contouring yields the best tumor VR and CI with internal-gross target volume contoured on MIP of 4DCT dataset, but 3DPET/CT and 4DCT MIP could not replace each other for motion encompassing target volume delineation for radiation treatment.

Comparison of patient-specific internal gross tumor volume for radiation treatment of primary esophageal cancer based separately on three-dimensional and four-dimensional computed tomography images

To compare the target volume, position and matching index of the patient-specific internal gross tumor volume (IGTV) based on three-dimensional (3D) and four-dimensional (4D) computed tomography (CT) images for primary esophageal cancer. Twenty-nine patients with primary thoracic esophageal cancer underwent 3DCT and 4DCT scans during free breathing. IGTVs were constructed using three approaches: combining the gross target volumes from the 10 respiratory phases of the 4DCT dataset to produce IGTV10 ; IGTV2 was acquired by combining the two extreme phases; and IGTV3D was created from the 3DCT-based gross target volume by enlarging the 95th percentile of motion in each direction measured by the 4DCT. 0.16 cm lateral (LR), 0.14 cm anteroposterior (AP) and 0.29 cm superoinferior (SI) in the upper; 0.18 cm LR, 0.10 cm AP and 0.63 cm SI in the middle; and 0.40 cm LR, 0.58 cm AP and 0.82 cm in the lower thoracic esophagus could account for 95% of respiratory-induced tumor motion. The centroid position shift between IGTV10 and IGTV2 was all below 0.10 cm, and less than 0.20 cm between IGTV10 and IGTV3D . IGTV10 was bigger than IGTV2 ; the mean value of matching index for IGTV2 to IGTV10 was 0.87 ± 0.05, 0.85 ± 0.06 and 0.83 ± 0.05 for upper, middle and distal thoracic esophageal tumors, respectively, and just 0.57 ± 0.11, 0.56 ± 0.13 and 0.40 ± 0.03 between IGTV3D and IGTV10 . 4DCT-based IGTV10 is a reasonable patient-specific IGTV for primary thoracic esophageal cancer, and IGTV2 is considered as an acceptable alternative to IGTV10 . However, it seems unreasonable to use IGTV3D substitute IGTV10 .

Investigation of the role of tryptophan residues in cationic antimicrobial peptides to determine the mechanism of antimicrobial action

AIMS

To understand the effects of Trp residues in linear antimicrobial peptides with α-helical conformations on cell permeation ability and membrane transduction efficacy.

METHODS AND RESULTS

A series of L-K6 analogues were designed and synthesized by replacing Ile or Leu with Trp at different positions on the hydrophobic face of L-K6. The antimicrobial and haemolytic activity and secondary structure of the designed Trp-containing peptides were assessed. In addition, the role of Trp in membrane disruption for these designed peptides was investigated. I1W, I4W and L5W demonstrated stronger activity than the other peptides against both Gram-positive and Gram-negative bacteria. All of the tested peptides preferentially interacted with negatively charged vesicles composed of phosphatidylglycerol (PG)/cardiolipin (CL) or PG/CL/phosphatidylethanolamine, and, to a lesser extent, with zwitterionic vesicles. I1W, I4W and L5W caused calcein release at 2·5 μmol l(-1) .

CONCLUSIONS

The position of Trp, rather than the number of Trp residues, in these peptides was an important factor in the antimicrobial activity. Trp residues were deeply inserted into negatively charged membranes but were largely exposed in aqueous buffer solution.

SIGNIFICANCE AND IMPACT OF THE STUDY

These Trp-containing peptides may represent good candidates for new antibiotic agents and for use in new therapeutic approaches.

Chemical fingerprinting of naphthenic acids and oil sands process waters-A review of analytical methods for environmental samples

This article provides a review of the routine methods currently utilized for total naphthenic acid analyses. There is a growing need to develop chemical methods that can selectively distinguish compounds found within industrially derived oil sands process affected waters (OSPW) from those derived from the natural weathering of oil sands deposits. Attention is thus given to the characterization of other OSPW components such as oil sands polar organic compounds, PAHs, and heavy metals along with characterization of chemical additives such as polyacrylamide polymers and trace levels of boron species. Environmental samples discussed cover the following matrices: OSPW containments, on-lease interceptor well systems, on- and off-lease groundwater, and river and lake surface waters. There are diverse ranges of methods available for analyses of total naphthenic acids. However, there is a need for inter-laboratory studies to compare their accuracy and precision for routine analyses. Recent advances in high- and medium-resolution mass spectrometry, concomitant with comprehensive mass spectrometry techniques following multi-dimensional chromatography or ion-mobility separations, have allowed for the speciation of monocarboxylic naphthenic acids along with a wide range of other species including humics. The distributions of oil sands polar organic compounds, particularly the sulphur containing species (i.e., OxS and OxS2) may allow for distinguishing sources of OSPW. The ratios of oxygen- (i.e., Ox) and nitrogen-containing species (i.e., NOx, and N2Ox) are useful for differentiating organic components derived from OSPW from natural components found within receiving waters. Synchronous fluorescence spectroscopy also provides a powerful screening technique capable of quickly detecting the presence of aromatic organic acids contained within oil sands naphthenic acid mixtures. Synchronous fluorescence spectroscopy provides diagnostic profiles for OSPW and potentially impacted groundwater that can be compared against reference groundwater and surface water samples. Novel applications of X-ray absorption near edge spectroscopy (XANES) are emerging for speciation of sulphur-containing species (both organic and inorganic components) as well as industrially derived boron-containing species. There is strong potential for an environmental forensics application of XANES for chemical fingerprinting of weathered sulphur-containing species and industrial additives in OSPW.

Rational design of anti-microbial peptides with enhanced activity and low cytotoxicity based on the structure of the arginine/histidine-rich peptide, chensinin-1

AIMS

To understand the structure-activity relationship of chensinin-1, a anti-microbial peptide (AMP) with an unusual structure, and to develop novel AMPs as therapeutic agents.

METHODS AND RESULTS

A series of chensinin-1 analogues were designed and synthesized by one to three replacement of glycines with leucines at the hydrophilic face of chensinin-1 or rearrangement of some of the residues in its sequence. Circular dichroism spectroscopy showed that the analogues adopted α-helical-type conformations in 50% trifluoroethanol/water but adopted β-strand-type conformations in 30 mmol l(-1) sodium dodecyl sulphate. The anti-microbial activities of the peptides against Gram-positive bacteria increased 5- to 30-fold, and these increases paralleled the increases in the peptides' hydrophobicities. Their haemolytic activities also increased. Amphipathicities had little influence on the bactericidal activity of chensinin-1. All peptides caused leakage of calcein entrapped in negatively charged liposomes although with different efficiencies. The peptides did not induce leakage of calcein from uncharged liposomes.

CONCLUSIONS

Peptide adopted an aperiodic structure can improve the anti-microbial potency by increasing peptide hydrophobicity. Its target is bacteria plasma membrane.

SIGNIFICANCE AND IMPACT OF THE STUDY

Chensinin-1 can act as a new lead molecule for the study of AMPs with atypical structures.

Risk factors for antimicrobial resistance among fecal Escherichia coli from residents on forty-three swine farms

Fecal Escherichia coli (n = 555) were isolated from 115 residents on 43 farrow-to-finish swine farms to determine the prevalence of antimicrobial resistance and associated risk factors. Susceptibility to 21 antimicrobials was determined and the overall prevalence of antimicrobial resistance was 25.8%. Pair-wise difference in prevalences of resistance to individual antimicrobials was significant between isolates from residents on farms that fed medicated swine rations compared to those that did not (p = 0.013). Cross-resistance among antimicrobials of same class and multidrug-resistance were observed. Logistic regression models revealed the following risk factors positively associated with antimicrobial resistance: use of antimicrobials in pigs on farms; number of hours per week that farmers spent in their pig barns; handling of sick pigs; and intake of antimicrobials by farm residents. This study indicates that occupational exposure of farmers to resistant bacteria and use of antimicrobials in pig farming may constitute a source of resistance in humans, although the human health impacts of such resistance is unknown. The consumption of antimicrobials by farmers appeared to constitute a significant risk for resistance development. Fecal E. coli from farm residents may act as a reservoir of resistance genes for animal and/or human pathogens.

Structural flexibility of laparoscopic instruments: implication for the design of virtual reality simulators

Laparoscopic training, under simulated settings, benefits from high fidelity models of the actual environment. This study was aimed at reducing uncertainty in the displacement and loads experienced by a laparoscopic instrument during surgical training. Infrared tracking of laparoscopic instruments is ineffective when real tissues attenuate the infrared signals. Incorporating the use of strain gauges for tip deflection measurements allows for online motion and load tracking during a procedure. Strain gauge voltages and infrared markers indicating displacement were both linear with respect to loads up to 700 grams. The resultant strain gauge voltage was equated to deflection values with a calibration constant. The results serve two purposes. First, it may enable the tracking and analysis of the skill level of novice surgeons using bench models. Second, the mechanical model of each instrument can be quantified and incorporated into virtual simulations, thus increasing model fidelity, effectively leading to better learning.

Contrast enhanced MR angiography in pulmonary sequestration

OBJECTIVE

To evaluate the feasibility of contrast enhanced three-dimensional (3D) magnetic resonance angiography (MRA) in identifying the systemic blood supply in pulmonary sequestration.

METHODS

Three patients who were suspected of pulmonary sequestration were examined by contrast enhanced 3D MRA. MR images were compared with surgical findings.

RESULTS

Contrast enhanced 3D MRA clearly demonstrated systemic arteries from the descending thoracic aorta supplying the basilar segments of the lower lobe in each case. Pulmonary veins from these segments, which drained into the left atrium in two cases, were also detected. MRA images were consistent with those observed in surgery.

CONCLUSION

Contrast enhanced 3D MRA allows accurate diagnosis of pulmonary sequestration and may obviate the need for more invasive investigations.

Arg-Tyr-Asp (RYD) and Arg-Cys-Asp (RCD) motifs in dendroaspin promote selective inhibition of beta1 and beta3 integrins

Arg-Gly-Asp (RGD) is a unique minimal integrin-binding sequence that is found within several glycoprotein ligands. This sequence has also been found in snake-venom anti-platelet proteins, including the disintegrins and dendroaspin, a natural variant of short-chain neurotoxins isolated from the venom of Dendroaspis jamesonii. In the present study, the motifs RYD and RCD were introduced into the dendroaspin scaffold to replace RGD. Both motifs in dendroaspin caused inhibition of ADP-induced platelet aggregation with IC(50) values of 200 and 300 nM respectively, similar to that of the wild-type RGD motif (170 nM). In comparison with wild-type dendroaspin, both RYD- and RCD-containing dendroaspins were more selective in the inhibition of the adhesion of K562 cells to laminin rather than to fibrinogen and fibronectin, even though they were 10-30-fold less potent at inhibiting K562 cell (containing alpha(5)beta(1) integrin) adhesion to laminin compared with wild-type. Interestingly, the RYD motif produced a similar IC(50) value to the RGD motif at inhibiting A375-SM cell (beta(3) integrin) adhesion to collagen, whereas the RCD motif was approx. 2-6-fold less potent compared with either RGD or RYD. These findings show that the selectivity of dendroaspin binding to beta(1) and beta(3) integrins can be modulated by the introduction of alternative cell recognition sequences.

Evaluation of the role of proline residues flanking the RGD motif of dendroaspin, an inhibitior of platelet aggregation and cell adhesion

The effect of a panel of proline mutants of dendroaspin, an inhibitor of platelet aggregation and cell adhesion, including A(42)-dendroaspin, A(47)-dendroaspin, A(49)-dendroaspin, A(42,47)-dendroaspin and A(47,49)-dendroaspin, was investigated using platelet-aggregation and cell-adhesion assays. Here we show that a single alanine-for-proline substitution did not affect potency when measured as the ability either to inhibit platelet aggregation induced by ADP (IC(50) approximately 170 nM) or to block transfected A375-SM cell adhesion to fibrinogen in the presence of Mn(2+) as compared with wild-type dendroaspin. By comparison, double proline substitution with alanines significantly reduced the potency in both assays by approx. 5-8-fold. These observations, therefore, suggest that proline residues flanking the RGD motif in dendroaspin and other RGD-containing venom proteins, e.g. disintegrins, may contribute to maintaining a favourable conformation for the solvent-exposed RGD site for its recognition by integrin receptors.

Detection of TT virus DNA in patients with liver disease and recipients of liver transplant

TT virus (TTV) is transfusion-transmissible but its involvement in post-transfusion hepatitis is uncertain. To investigate the potential association of TTV with liver diseases, the prevalence of TTV DNA was tested by semi-nested PCR in 113 carriers of hepatitis C virus (HCV), 10 patients with acute liver failure, 11 patients with cryptogenic cirrhosis and 200 control blood donors. Thirty-seven of these patients underwent liver transplantation and were tested pre- and post-transplantation. TTV DNA was semi-quantified in serial samples from seven patients with unexplained post-transplant hepatitis. TTV genotyping was performed on samples from 28 patients by sequence analysis. The prevalence of TTV DNA in blood donors was 1.5% and 17% in HCV infected haemophiliacs. In patients with acute or chronic liver disease or hepatitis, 6 to 27% prevalence was observed. After liver transplantation, the prevalence of TTV DNA increased from 16 to 46% (P < 0.01). In patients who developed unexplained hepatitis post-transplantation, TTV viraemia did not parallel ALT levels. TTV DNA either increased in titre or became detectable shortly after transplantation, suggesting that either TTV was transfusion-transmitted, or, more likely, that immunosuppression caused a recurrence of low level or undetectable TTV viraemia. TTV had considerable genomic diversity in the N22 region, corresponding to at least 4 genotypes. Genotype 2 was found in 14/28 patients.

Detection of TT virus DNA in patients with liver disease and recipients of liver transplant

TT virus (TTV) is transfusion-transmissible but its involvement in post-transfusion hepatitis is uncertain. To investigate the potential association of TTV with liver diseases, the prevalence of TTV DNA was tested by semi-nested PCR in 113 carriers of hepatitis C virus (HCV), 10 patients with acute liver failure, 11 patients with cryptogenic cirrhosis and 200 control blood donors. Thirty-seven of these patients underwent liver transplantation and were tested pre- and post-transplantation. TTV DNA was semi-quantified in serial samples from seven patients with unexplained post-transplant hepatitis. TTV genotyping was performed on samples from 28 patients by sequence analysis. The prevalence of TTV DNA in blood donors was 1.5% and 17% in HCV infected haemophiliacs. In patients with acute or chronic liver disease or hepatitis, 6 to 27% prevalence was observed. After liver transplantation, the prevalence of TTV DNA increased from 16 to 46% (P < 0.01). In patients who developed unexplained hepatitis post-transplantation, TTV viraemia did not parallel ALT levels. TTV DNA either increased in titre or became detectable shortly after transplantation, suggesting that either TTV was transfusion-transmitted, or, more likely, that immunosuppression caused a recurrence of low level or undetectable TTV viraemia. TTV had considerable genomic diversity in the N22 region, corresponding to at least 4 genotypes. Genotype 2 was found in 14/28 patients.

Hypervariable region diversity of hepatitis C virus and humoral response: comparison between patients with or without cirrhosis

To investigate the potential clinical utility of antibody response to HVR1 of HCV, the genomic and amino acid diversity of HVR1 was compared between two groups of four chronic HCV carriers with or without liver cirrhosis. Peptides corresponding to the deduced COOH- and NH2-terminal amino acid sequences of HVR1 were synthesised to assess the reactivity of patient sera to autologous and homologous HVR1 epitopes by enzyme-linked immunosorbent assay. HCV chronic carriers had significantly more frequent cross-reactivity with homologous C- than N-terminal HVR1 peptides. Twelve cirrhotic and eleven noncirrhotic patients had a similar frequency of cross-reactivity with either C- or N-terminal HVR1 peptides. However, noncirrhotic patients had a significantly higher level of C-terminal HVR1 antibody cross-reactivity than cirrhotic patients. In HCV chronic carriers, the magnitude of the immune response to but not the frequency of cross-reactivity with C-terminus HVR1 peptides differ between patients with and without liver cirrhosis.

Broadly cross-reactive, high-affinity antibody to hypervariable region 1 of the hepatitis C virus in rabbits

The HCV hypervariable region 1 (HVR1) of the main E2 envelope protein is critically important in HCV neutralization but its extreme variability makes immune therapy and vaccine development particularly difficult. To explore the hypothesis that HVR1 carries a common epitope susceptible of eliciting cross-reactive neutralizing and inhibitory antibodies, rabbits were immunized with a series of synthetic HVR1 peptides. The anti-HVR1 produced were purified and characterized. Several lines of evidence supported the working hypothesis: (1) although injected only once, a boosting effect from poorly homologous peptides was observed; (2) purified rabbit IgG reacted with high affinity with immunizing peptides and cross-reacted with 16 of 17 unrelated HVR1 peptides; (3) antibodies appeared of restricted diversity irrespective of the linear HVR1 peptide sequences; (4) anti-HVR1 peptides effectively captured HCV in 22 of 33 plasmas from random infected patients; (5) anti-HVR1 IgG blocked the binding of antibody-captured HCV to MOLT-4 cells. These findings suggest that with an appropriate HVR1 peptide immunization scheme, high titer, broadly cross-reactive, blocking antibodies to HCV can be produced. Antibodies to the putative ubiquitous HVR1 epitope may have important clinical uses.

[Dynamic study of anti-NS5 and ALT in post-transfusion hepatitis C]

In order to study the character and dynamic changes of HCV NS5 antigen in post-transfusion hepatitis C, EIA was established with fusion protein, and different groups of population were investigated. The results showed the positive rate of whole blood donor, normal people, chronic hepatitis C patients and post transfusion hepatitis C patients is 0.0%, 1.66%, 50.7% and 70.5%, respectively. Serial blood samples of 25 cases of acute or chronic post-transfusion hepatitis C were detected, and the results indicated that the antibody of NS5 appeared relatively late, and the serum conversion time was 182.9 +/- 168.5 days. The anti-NS5 positive rate in 1, 3, 6, 12 and 24 months after HCV infection was 28%, 40%, 52%, 68% and 76%, respectively. The positive rate of anti-NS5 in sera with HCV RNA was 61.9%. Analysis on the appearance of antibody to the different antibody region of the gene, ALT and HCV RNA showed the dynamic changes of anti-NS5 were corresponding to the serum ALT in some cases, indicating antibody of NS5 appear later and may reflect the disease activity to some extent. The dynamic changes of anti-NS5 are of four kinds: transient positive, intermittent positive, persistent positive and persistent negative in during the two years period.

[Cloning and sequencing of cDNA of E2/NS1 gene of hepatitis C virus]

Hepatitis C virus (HCV) RNA extracted from serum of a patient infected with HCV in Beijing was converted to cDNA by reverse transcription. HCV E2/NS1 gene (approximately 930 bp) was amplified by nested polymerase chain reaction and was inserted into pGEM-T plasmid vector. The 431 bp nucleotide sequence at 5' terminus of this gene was determined by dideoxy-mediated chain termination method. The result of comparison of this sequence and sequences of another 9 HCV isolates suggested that the isolate we obtained was highly homologous to HCV genotype II. There are two hypervariable regions (HVR) at the N terminus of envelope protein encoded by HCV E2/NS1 gene. Several relatively conserved amino acid residues and areas located in and out of HVR were also observed. They are concerned in maintenance of spatial conformation of HCV envelope protein, but their immune function remains to be further studied.

Herpes simplex virus type 1 in brain and risk of Alzheimer's disease

BACKGROUND

The apolipoprotein E epsilon 4 (APOE-epsilon 4) allele is a risk factor for Alzheimer's disease (AD), but it is neither essential nor sufficient for development of the disease. Other factors-genetic or environmental-must therefore have a role. By means of a PCR we have detected herpes simplex virus type 1 (HSV1) in latent form in brains of elderly people with and without AD. We have postulated that limited reactivation of the virus causes more damage in AD patients than in elderly people without AD because of a difference in the hosts. We now report the APOE genotypes of AD patients and non-AD sufferers with and without HSV1 in brain.

METHODS

DNA was extracted from 84 samples of brain from 46 AD patients (39 temporal lobe, 39 frontal lobe, three hippocampus) and from 75 samples of brain from 44 non-AD elderly people (33 temporal lobe, 36 frontal lobe, six hippocampus). PCR amplification was used to detect HSV1 thymidine kinase gene and the host APOE gene.

FINDINGS

By multiple logistic regression, the APOE-epsilon 4 allele frequency was significantly higher in the patients positive for HSV1 in brain than in the HSV1-negative AD group, the HSV1-positive non-AD group, or the HSV1-negative non-AD group (52.8% vs 10.0%, 3.6%, and 6.3%, respectively). The odds ratio for APOE-epsilon 4 in the HSV1-positive AD group compared with HSV1-negative non-AD group was 16.8 (95% CI 3.61-77.8) and in the HSV1-negative AD group, 1.67 (0.21-13.4). We also compared APOE genotypes of 40 people who had recurrent cold sores and 33 non-sufferers; the APOE-epsilon 4 allele frequencies were 36% and 9%, respectively (p < 0.0001).

INTERPRETATION

These findings suggest that the combination of HSV1 in brain and carriage of an APOE-epsilon 4 allele is a strong risk factor for AD, whereas either of these features alone does not increase the risk of AD. The findings in people with cold sores support our hypothesis that APOE-epsilon 4 and HSV1 together are damaging in the nervous system.

Neurotropic viruses and Alzheimer disease. Interaction of herpes simplex type 1 virus and apolipoprotein E in the etiology of the disease

Infectious agents have been proposed as possible etiological factors in sporadic cases of Alzheimer disease (AD), herpes simplex type 1 virus (HSV1) being a likely candidate. We have detected laten HSV1 in brain from AD patients and from aged normal individuals, using polymerase chain reaction (PCR), in the regions most affected in the disease. In contrast, we have not detected another neurotropic herpes virus, varicella zoster (VZV), in any brains. We have postulated that HSV1 reactivates periodically, and that a host or viral characteristic determines the degree of damage caused by the resulting acute infection-with much greater damage in the case of AD patients. We have therefore examined a host factor-the apolipoprotein E (apoE) genotype, since the E4 allele is a known risk factor in the disease. We have found that the risk of developing AD is much greater in those who are HSV1-positive in brain and who possess an apoE4 allele than for those with only one of these factors.

[Pharmacological study on anti-hepatitis effect of Cotinus coggygria Scop. Syrup]

This paper shows that the Cotinus coggygria syrup has the effect of protecting the liver from chemical damages, reducing tension of the choledochal sphincter, increasing the bile flow and raising the body immunity. The anti-hepatitis effect may be carried out through decreasing transaminase, normalizing functioning of the gallbladder, reducing icterus and enhancing the immunity of the body.