Production of MSTN knockout porcine cells using adenine base-editing-mediated exon skipping

Gene-knockout pigs have important applications in agriculture and medicine. Compared with CRISPR/Cas9 and cytosine base editing (CBE) technologies, adenine base editing (ABE) shows better safety and accuracy in gene modification. However, because of the characteristics of gene sequences, the ABE system cannot be widely used in gene knockout. Alternative splicing of mRNA is an important biological mechanism in eukaryotes for the formation of proteins with different functional activities. The splicing apparatus recognizes conserved sequences of the 5' end splice donor and 3' end splice acceptor motifs of introns in pre-mRNA that can trigger exon skipping, leading to the production of new functional proteins, or causing gene inactivation through frameshift mutations. This study aimed to construct a MSTN knockout pig by inducing exon skipping with the aid of the ABE system to expand the application of the ABE system for the preparation of knockout pigs. In this study, first, we constructed ABEmaxAW and ABE8eV106W plasmid vectors and found that their editing efficiencies at the targets were at least sixfold and even 260-fold higher than that of ABEmaxAW by contrasting the editing efficiencies at the gene targets of endogenous CD163, IGF2, and MSTN in pigs. Subsequently, we used the ABE8eV106W system to realize adenine base (the base of the antisense strand is thymine) editing of the conserved splice donor sequence (5'-GT) of intron 2 of the porcine MSTN gene. A porcine single-cell clone carrying a homozygous mutation (5'-GC) in the conserved sequence (5'-GT) of the intron 2 splice donor of the MSTN gene was successfully generated after drug selection. Unfortunately, the MSTN gene was not expressed and, therefore, could not be characterized at this level. No detectable genomic off-target edits were identified by Sanger sequencing. In this study, we verified that the ABE8eV106W vector had higher editing efficiency and could expand the editing scope of ABE. Additionally, we successfully achieved the precise modification of the alternative splice acceptor of intron 2 of the porcine MSTN gene, which may provide a new strategy for gene knockout in pigs.

[Proliferative lesions with mesonephric features in the gynecologic tract: a clinicopathological analysis of sixteen cases]

Objective: To investigate the clinicopathological features of proliferations with mesonephric features (PMF) of the gynecologic tract. Methods: A retrospective analysis was performed on the clinical and pathological data of 16 cases with PMF that were diagnosed from October 2016 to January 2022 at a single institution. The relevant literature was reviewed. Results: Among the 16 cases, with an average of 53 years (31-68 years), there were 5 cases of mesonephric hyperplasia, 4 cases of mesonephric adenocarcinoma and 7 cases of mesonephric-like adenocarcinoma. The five cases of mesonephric hyperplasia were located in the lateral wall of the cervix and composed of simple tubules with growth patterns of diffuse or lobular clusters, without obvious stromal reaction. Four cases of mesonephric adenocarcinoma consisted of a mixture of papillary, cribriform, solid and other architectures, the nuclei resembling these of papillary thyroid carcinoma, and strong fibroproliferative reaction. They were located deep in the cervical and vaginal stroma. One of the tumors showed atypical mesonephric hyperplasia adjacent to the tumor. Five uterine and two ovarian mesonephric-like adenocarcinoma cases had similar histological morphology with mesonephric adenocarcinoma, but no mesonephric remnants/mesonephric hyperplasia were found near the tumors. In addition, four (4/5) uterine mesonephric-like adenocarcinoma cases originated from the endometrium with secondary involvement of myometrium, including one case with clear demarcation between the normal endometrium and the neoplastic glands. One (1/5) uterine mesonephric-like adenocarcinoma case was mainly located in the deep myometrium, along with adenomyosis around the tumor, without mesonephric remnants. Two ovarian mesonephric-like adenocarcinoma cases were associated with endometriotic cyst/endometrioid cystadenoma, including one case with an abrupt transition between normal epithelium and atypical mesonephric cells within the single individual cyst directly adjacent to tumor. All mesonephric hyperplasia and mesonephric adenocarcinoma cases were positive for GATA3, PAX8 and CD10 in a varying degree, and negative for ER, PR and TTF1. Although mesonephric-like adenocarcinoma showed a considerable overlap of immunohistochemical expression with mesonephric adenocarcinoma, seven mesonephric-like adenocarcinoma cases were positive for TTF1 and negative for GATA3. Conclusions: PMF is a class of rare proliferative lesions with morphological and immunophenotypic characteristics of mesonephric duct. Its commonly involved site, microscopic morphology, associated benign and/or atypical lesions, and immunophenotype may contribute to its diagnosis and differential diagnosis.

Tyrosine Sulphation of CXCR4 Induces the Migration of Fibroblast in OSF

Oral submucous fibrosis (OSF) caused by areca nut chewing is a prevalent fibrotic disease in Asia-Pacific countries. Arecoline-induced migration of fibroblasts (FBs) plays a vital role in the development of OSF. However, the specific molecular mechanisms involved remain unclear. Many studies have shown that tyrosine sulphation of chemokines can influence cell migration. Herein, we demonstrated that arecoline stimulates tyrosine sulphation of the chemokine receptor 4 (CXCR4) through the tyrosylprotein sulphotransferase-1 (TPST-1) to enhance the migration ability of FBs. Moreover, by RNA-Seq analysis, we found that the most significantly altered pathway was the EGFR pathway after the arecoline stimulation for FBs. After the knockdown of arecoline-induced EGFR expression, the tyrosine sulphation of CXCR4 was significantly decreased by the inhibition of TPST-1 induction. Finally, in human OSF specimens, TPST-1 expression was directly correlated with the expression of CXCR4. These data indicate that the arecoline-induced tyrosine sulphation of CXCR4, which is regulated by TPST-1, might be a potential mechanism that contributes to FB migration in OSF.

[A retrospective cohort study of incidence of anemia and risk factors in HIV/AIDS patients with access to antiretroviral therapy in Dehong Jingpo and Dai Autonomous Prefecture in Yunnan province, 2004-2018]

Objective: To investigate the incidence of anemia and risk factors in HIV/AIDS patients with access to antiretroviral therapy (ART) during 2004-2018 in Dehong Jingpo and Dai Autonomous Prefecture (Dehong). Methods: A retrospective cohort study was conducted in HIV/AIDS patients receiving ART in Dehong during 2004-2018 based on the data extracted from the National HIV/AIDS antiretroviral therapy database. Cox proportional risk model was used to analyze the factors associated with the incidences of anemia and moderate or severe anemia in the HIV/AIDS patients. And the piecewise linear mixed-effects model was used to depict the trajectory of hemoglobin changes over time after initiating ART according to baseline level. Results: A total of 8 044 HIV/AIDS patients were included, in whom 6 337 (78.8%) were without anemia at baseline survey and had a median follow up time of 4.43 (P₂₅, P₇₅: 1.50, 6.71) years. The median follow up time for 1 291 new anemia cases and 293 new moderate or severe anemia cases was 0.16 (P₂₅, P₇₅: 0.07, 1.99) years and 0.48 (P₂₅, P₇₅:0.09, 2.97) years, respectively. The incidence rate of anemia and moderate or severe anemia was 4.40 per 100 person-years and 0.41 per 100 person-years respectively. In multivariable Cox regression analysis, older age, being female, being in Dai and Jingpo ethnic group, baseline BMI <18.5 kg/m², baseline CD4⁺T lymphocyte cell counts (CD4) <200 cells/μl, and zidovudine (AZT) -based initial treatment regimen were factors significantly and positively associated with incidence of anemia after treatment. Factors as being female, being in Dai ethnic group, baseline BMI <18.5 kg/m², mild baseline anemia, and AZT-based initial treatment regimen were significantly and positively associated with incidence of moderate or severe anemia after treatment. Conclusion: The risk for anemia was higher in HIV/AIDS patients with specific characteristics, such as age ≥60 years , being female, being in Dai and Jingpo ethnic groups, lower BMI, CD4 <200 cells/μl, and treatment of AZT, after initiation of ART in Dehong during 2004-2018. Additional efforts are needed to strengthen the screening, prevention and treatment of anemia in this population.

[Incidence and influencing factors of AIDS-related and non-AIDS-related deaths after receiving antiretroviral therapy among HIV-positive individuals in Dehong Dai and Jingpo Autonomous Prefecture, 2010-2019]

Objective: To explore the changing trends and influencing factors of AIDS-related and non-AIDS-related deaths after receiving antiretroviral therapy (ART) among HIV-positive individuals in Dehong Dai Jingpo autonomous prefecture (Dehong) from 2010 to 2019. Methods: Based on the Chinese National treatment database, HIV patients who initiated ART from 2010 to 2019 were included in the analysis. The cumulative incidence function was used to estimate the cumulative incidence of AIDS-related death and non-AIDS-related death, respectively. The Fine-Grey model was used to compare the differences between AIDS-related and non-AIDS-related deaths and analyze its influencing factors. Results: A total of 7 068 HIV-positive individuals were included, of which 388 were AIDS-related deaths and 570 were non-AIDS-related deaths. The cumulative mortality rate at years 1, 2, 3, 4, 5, 7 and 9 after receiving ART were 2.27%, 3.46%, 4.47%, 5.03%, 5.84%, 6.61%, 7.40% for AIDS-related deaths, and 1.63%, 3.11%, 4.68%, 6.02%, 7.42%, 10.49%, 12.75% for non-AIDS-related deaths, respectively. In the Fine-Grey model, older age at ART initiation, male, unmarried, injection drug use as the transmission route, lower baseline BMI, lower baseline CD4⁺ T cell counts, baseline FIB-4 score >3.25, and baseline anemia were risk factors for AIDS-related death. In contrast, age at ART initiation ≥45 years, male, Dai, and Jingpo minority ethnicities, unmarried, injection drug use as the transmission route, lower baseline BMI, baseline FIB-4 score >3.25, baseline eGFR <60 ml·min^-1·1.73 m^-2, and baseline anemia were risk factors for non-AIDS-related deaths. Conclusions: The cumulative mortality rate was low among HIV-positive individuals after receiving ART in Dehong during 2010-2019. The mortality of non-AIDS-related deaths was higher than that of AIDS-related deaths. There were also differences in the factors influencing AIDS-related and non-AIDS-related deaths and interventions should be intensified to target the influencing factors for non-AIDS-related deaths.

Effect of congenital heart disease on the recurrence of cough variant asthma in children

Background

The research into the recurrence of cough variant asthma (CVA) in congenital heart disease (CHD) are few in number. The purpose of this study is to investigate the effect of CHD on the risk of the recurrence of CVA.

Methods

This study was a retrospective cohort study of 489 children with CVA aged between one and 14 years, of whom 67 had CHD complicated with CVA and 134 had CVA without CHD at a ratio of 1:2 according to age, sex and index year. The adjusted hazard ratio (aHR) of CVA recurrence in both the CHD cohort and the non-CHD cohort was determined by multivariate analysis using the Cox proportional hazard regression model.

Results

Adjusting for CHD classification, Mycoplasma pneumonia (MP) infection and immunoglobulin E (IgE) sensitization, the recurrence hazard of CVA in the complex congenital heart disease (CCHD) group (aHR = 3.281; 95% CI 1.648–6.530; P < 0.01) was significantly higher than that in the simple congenital heart disease group (aHR = 2.555; 95% CI 1.739–3.752; P < 0.01). Further, children with IgE sensitization (aHR = 2.172; 95% CI 1.482–3.184; P < 0.01) had a higher recurrence hazard of CVA than those without IgE sensitization, and children with MP infection (aHR = 1.777; 95% CI 1.188–2.657; P < 0.01) had a higher recurrence hazard of CVA than those without the MP infection.

Conclusion

The hazard of recurrent CVA is higher in children with CHD, especially in the CCHD children. In addition, those children with IgE sensitization or a MP infection had an increased hazard of recurrent CVA.

[Association of maternal nocturnal sleep throughout pregnancy with the early nocturnal sleep of infants]

Objective: To investigate the association between maternal nocturnal sleep during pregnancy and their infants' nocturnal sleep patterns in early infancy by establishing a birth cohort. Methods: In this prospective study,healthy pregnant women and their infants were recruited in Chongqing Health Center for Women and Children from September 2013 to January 2014. A total of 40 healthy pregnant women and their infants were enrolled, and 34 pairs (85%) completed the whole survey. Actiwatch, wearing on the mother's wrist or infant's ankle,was used to monitor nighttime sleep at home for 7 times in total,with 7 consecutive days for each monitoring course. Pregnant women were monitored at 16, 24, 32 weeks gestational age, and were required to finish Pittsburgh Sleep Quality Index (PSQI) scale at the end of each monitoring. Their infants were initially monitored at 14 days after birth, followed by 1(st), 2(nd), and 3(rd) month after birth,with sleep diary recorded by parents. Pearson correlation analysis and multivariate linear regression were used to investigate the potential correlation between these two sleep patterns. Results: The average nocturnal sleep time was (465±53) min throughout pregnancy, with increased trend in the latency of maternal nighttime sleep onset ((30±15), (34±29), (38±30) min) while decreasing of average sleep efficiency ((85±5)%, (84±8)%, (83±8)%). The longest night sleep duration decreased from (382±74) min in the first trimester to (330±83) min in the third trimester (F=4.932, P<0.05), while awakening time after sleep onset (WASO) correspondingly increased from (27±22) min to (53±25) min (F=12.605, P<0.05). In terms of infants, the latency of nighttime sleep onset decreased from (43±33) min on the 14th day to (20±29) min at 3-month of age (t=3.281, P=0.002), while the longest nighttime sleep duration increased from (20±62) min to (265±140) min (t=3.867, P<0.01); meanwhile, the total nocturnal sleep time and the sleep efficiency increased from (373±126) min and (63±28)% to (431±103) min and (75±16)%, respectively (t=2.362, P=0.024; t=2.418, P=0.039, respectively). After adjusting for maternal age and body mass index (BMI), parental educational level and family income, maternal mood, exposure to tobacco and alcohol during pregnancy, method of delivery, as well as infants' gender, feeding patterns and gestational weeks, the regression analysis showed that the total nocturnal sleep time and the longest nighttime sleep duration during pregnancy were positively correlated with the corresponding parameters of their infants at the age of 3 months (B=0.541, 95%CI 0.168-0.914, t=2.882, P=0.005; B=0.310, 95%CI 0.035-0.586, t=2.240, P=0.027, respectively). Conclusions: The total nocturnal sleep time and the longest nighttime sleep duration during pregnancy are positively correlated with the corresponding parameters of their infants in early infancy. Paying more attention to improve maternal sleep quality may facilitate their infants to establish sleep-wake patterns early.

Manipulation of intestinal dysbiosis by a bacterial mixture ameliorates loperamide-induced constipation in rats

Constipation has a significant influence on quality of life. Patients with constipation have slow waves in their gastrointestinal smooth muscles and less faecal water contents, which are closely associated with down-regulation of the interstitial cells of Cajal (ICC) in the gastrointestinal muscles and the aquaporin protein AQP3 expressed in colon epithelial cells. Recent studies supported that patients with constipation have altered intestinal microbial structures compared with healthy controls. Intestinal dysbiosis might be one possible pathophysiological mechanism causing constipation. Bacterial strains, such as Lactobacillus spp., have shown many beneficial effects on the amelioration of constipation. However, few studies reported the structural changes of intestinal microbiota post-intervention of probiotics. In this study, a bacterial mixture was administrated to rats with loperamide-induced constipation. Effects of the bacterial mixture on small intestine transit (SIT), faecal water content, and the intestinal microbiome in rats were evaluated. Meanwhile, we investigated several factors involved in signalling pathways that regulate function of ICC and expression of AQP3 to discuss the possible underlying molecular mechanisms. Intervention of the bacterial mixture improved SIT and faecal water content in constipated rats. The up-regulation of C-kit/SP signalling pathways in ICC and AQP3 significantly contributed to improvements. These changes were closely associated with the manipulation of intestinal dysbiosis in constipated rats. Furthermore, our results revealed the important role of intestinal microbiota in affecting gut motility through regulation of serotonin biosynthesis. This monoamine neurotransmitter, secreted from enterochromaffin cells, up-regulated both substance P/neurokinin 1 receptors pathway of ICC and the expression of AQP3 in intestinal epithelial cells. Our study suggested that the disrupted microbiome in patients could be a potential therapeutic target for the improvement of constipation.

A new phase of phosphorus: the missed tricycle type red phosphorene

We predict a new two-dimensional allotrope of phosphorus, which we call red phosphorene, by restructuring the segments of the previously proposed blue and black phosphorenes. Its atomic and electronic structures as well as the thermodynamic and dynamic stabilities are systematically studied by first-principles calculations. The results indicate that the red phosphorene is dynamically stable and possesses remarkably thermodynamical stability comparable to that of the black one. Because of the sp(3)-hybridization and the formation of a localized lone pair, red phosphorene is a semiconductor with an indirect band gap of about 1.96 eV, which can be effectively modulated by in-plane strains due to its wave-like configuration. We find that the red, black and blue phosphorenes show evident distinction in their layer thicknesses, surface work functions, and possible colors, based on which one can distinguish them in future experiments.

Effective Resistance to Wheat Stripe Rust in a Region with High Disease Pressure

Stripe rust is a major fungal disease of wheat. It frequently becomes epidemic in southeastern Gansu province, a stripe rust hot spot in China. Evaluations of wheat germplasm response are crucial for developing cultivars to control the disease. In total, 57 wheat cultivars and lines from Europe and other countries, comprising 36 cultivars with documented stripe rust resistance genes and 21 with unknown genes, were tested annually with multiple races of Puccinia striiformis f. sp. tritici in the field at Tianshui in Gansu province from 1993 to 2013. Seven wheat lines were highly resistant, with infection type (IT) 0 during the entire period; 16 were moderately resistant (IT 0;-2); and 26 were moderately susceptible (IT 0;-4), with low maximum disease severity compared with the susceptible control Huixianhong. 'Strampelli' and 'Libellula', with three and five quantitative trait loci, respectively, for stripe rust resistance have displayed durable resistance in this region for four decades. Ten cultivars, including 'Lantian 15', 'Lantian 26', and 'Lantian 31', with stripe rust resistance derived from European lines, were developed in our breeding program and have made a significant impact on controlling stripe rust in southeastern Gansu. Breeding resistant cultivars with multiple adult-plant resistance genes seems to be a promising strategy in wheat breeding for managing stripe rust in this region and other hot spots.

Mn²+-bonded reduced graphene oxide with strong radiative recombination in broad visible range caused by resonant energy transfer

The photoluminescence (PL) characteristics of Mn(2+)-bonded reduced graphene oxide (rGO) are studied in details. The Mn(2+)-bonded rGO is synthesized using MnO(2)-decorated GO as the intermediate products and ideal tunable PL is obtained by enhancing the long-wavelength (450-550 nm) emission. The PL spectra excited by different wavelengths are analyzed to elucidate the mechanism, and the resonant energy transfer between Mn(2+) and sp(2) clusters of the rGO appears to be responsible for the enhanced long-wavelength emission. To examine the effect of Mn(2+) on the long-wavelength emission from the Mn(2+)-bonded rGO, the PL characteristics of Mn(2+)-bonded rGO with smaller Mn concentrations are studied and weaker emission is observed. Our theoretical calculation corroborates the experimental results.

Under- and over-consumption intermittent TB treatment among rural TB patients in south-west China

OBJECTIVE

To assess adherence to intermittent directly observed treatment (DOT) during the 2-month intensive phase of tuberculosis (TB) treatment in south-west rural China.

DESIGN

A cross-sectional study was conducted in Simao Prefecture, Yunnan Province, China. One hundred and thirty new TB patients registered under DOTS and treated during the 2-month intensive phase and their observers were separately interviewed at their homes using structured questionnaires. Numbers of packs of TB drugs were checked on the spot.

RESULTS

Of 130 visits, the same percentage (3.1%) of patients and their observers reported missing > or =2 consecutive weeks of treatment (prevalence-adjusted kappa = 0.94). The percentages who missed > or =20% of the packs, as reported by patients and observers, were 3.8 and 2.3, respectively (prevalence-adjusted kappa = 0.969). According to the pill count, nine patients (7%) had missed > or =20% of the packs, 10 had over-consumed TB drugs and two had lost respectively five and six packs. Eight of the 10 who had over-consumed had done so due to confusion in the days of the month, and two because they wanted a quicker recovery.

CONCLUSIONS

Intermittent regimens in China need to be more carefully monitored to avoid over-consumption of anti-tuberculosis drugs in addition to non-adherence due to under-consumption.

Silencing of episomal transgene expression by plasmid bacterial DNA elements in vivo

We previously demonstrated that sustainable enhanced levels of transgene products could be expressed from a bacterial DNA-free expression cassette either formed from a fragmented plasmid in mouse liver or delivered as a minicircle vector. This suggested that bacterial DNA sequences played a role in episomal transgene silencing. To further understand the silencing mechanism, we systematically altered the DNA components in both the expression cassette and the bacterial backbone, and compared the gene expression profiles from mice receiving different DNA forms. In nine vectors tested, animals that received the purified expression cassette alone always expressed persistently higher levels of transgene compared to 2fDNA groups. In contrast, animals that received linearized DNA by a single cut in the bacterial backbone had similar expression profiles to that of intact plasmid groups. All three linear DNAs formed large concatemers and small circles in mouse liver, while ccDNA remained intact. In all groups, the relative amount of vector DNA in liver remained similar. Together, these results further established that the DNA silencing effect was mediated by a covalent linkage of the expression cassette and the bacteria DNA elements.

[Detection of DNA of Toxoplasma gondii in rat by using polymerase chain reaction]

OBJECTIVE

To study the significance of DNA of Toxoplasma gondii in peripheral blood.

METHODS

DNA of T. gondii in peripheral blood of 50 infected rats was detected by polymerase chain reaction. A pair of primers was designed, according to the sequence P30 gene specific to T. gondii, to amplify DNA from T. gondii by PCR.

RESULTS

The primers amplified DNA specifically from T. gondii and could not amplify DNA from humans, uninfected rat and mouse and from Trichomonas vaginalis and Entamoeba histolytica. DNA of two Toxoplasma parasites was detected by 35 cycles of amplification, indicating a fair sensitivity of the PCR system.

CONCLUSION

PCR may have a value for early diagnosis of T. gondii infection in rat.

[Construction and analysis of a genetic linkage map of soybean]

A high-density genetic map was constructed with a RILs population (NJRIKY) from a cross of two cultivated soybean Kefeng 1 and Nannong 1138-2, using RFLP, SSR, RAPD and AFLP markers. The map consists of 24 linkage groups, which include 792 genetic markers, and covers 2,320.7 cM with an average genetic distance of 2.9 cM. The higher polymorphsims between two parents were identified with SSR markers. Due to its simplicity and stability, they could be used as anchored marker to integrate different maps constructed with different genetic markers. AFLP marker system is efficient for map construction while it easily form clusters to cause big gaps in the map. A total of 21.7% of markers was found with distorted segregation in the RILs population. The high-density molecular linkage map is fundamental for gene localization, comparative genomics, and QTL mapping of important agronomic traits.

[Application of artificial neural network to simultaneous spectrophotometric determination of Cu, Co and Ni]

By means of artificial neural network and Levenberg-Marquardt back-propagation train algorithm, the three-component metal coordinate compounds of PAR-Cu, Co, Ni were determined simultaneously, in which the spectra overlapped. In 452-552 nm, the absorbance(A) at 14 wavelength were taken as character of artificial neural network, and samples were arranged by method of orthogonal design. The mean recovery of Cu, Co, Ni were 99.96%, 99.99% and 99.97% respectively. The RSD of the results were 0.1%, 0.2% and 0.1% respectively. The results were better than those of other networks in training speed and the accuracy. In conclusion, the new network spectrophotometry is a good choice for resolving multicomponent.

Targeting and processing of nuclear-encoded apicoplast proteins in plastid segregation mutants of Toxoplasma gondii

The apicoplast is a distinctive organelle associated with apicomplexan parasites, including Plasmodium sp. (which cause malaria) and Toxoplasma gondii (the causative agent of toxoplasmosis). This unusual structure (acquired by the engulfment of an ancestral alga and retention of the algal plastid) is essential for long-term parasite survival. Similar to other endosymbiotic organelles (mitochondria, chloroplasts), the apicoplast contains proteins that are encoded in the nucleus and post-translationally imported. Translocation across the four membranes surrounding the apicoplast is mediated by an N-terminal bipartite targeting sequence. Previous studies have described a recombinant "poison" that blocks plastid segregation during mitosis, producing parasites that lack an apicoplast and siblings containing a gigantic, nonsegregating plastid. To learn more about this remarkable phenomenon, we examined the localization and processing of the protein produced by this construct. Taking advantage of the ability to isolate apicoplast segregation mutants, we also demonstrated that processing of the transit peptide of nuclear-encoded apicoplast proteins requires plastid-associated activity.

Linear DNAs concatemerize in vivo and result in sustained transgene expression in mouse liver

The short duration of transgene expression remains a major obstacle for the implementation of nonviral DNA vectors in clinical gene therapy trials. Here, we demonstrate stable, long-term transgene expression in vivo by transfecting a linear DNA expression cassette (LDNA) into mouse liver. Interestingly, despite similar quantities and cellular distribution of injected DNAs in their livers, mice receiving LDNA encoding human alpha1-antitrypsin (hAAT) expressed approximately 10- to 100-fold more serum hAAT than mice injected with closed circular (cc) DNA for a period of 9 months (length of study). Furthermore, when a linear human factor IX expression cassette was delivered to factor IX-deficient mice, sustained serum concentrations of more than 4 microg/ml (80% of normal) of the human clotting factor and correction of the bleeding diathesis were obtained. Southern blot analyses indicate that, unlike ccDNA, LDNA rapidly formed large, unintegrated concatemers in vivo, suggesting that transgene persistence from plasmid-based vectors was influenced by the structure of the vector in transfected cells. No differences in transgene expression or DNA molecular structures were observed when AAV ITRs were included to flank the hAAT expression cassette in both ccDNA- and LDNA-treated animals. Linear DNA transfection provides an approach for achieving long-term expression of a transgene in vivo.

[Microsatellite marker analysis of a soybean recombinant inbred line NJRIKY]

The prerequisite of genomic research such as genetic mapping is construction of a suitable segregating population and its reasonable evaluation before use. A recombinant inbred line (RILs), NJRIKY, was constructed through a cross between Kefeng 1 and Nannong 1138-2. The present study was focused on evaluation of genetic structure of the RILs through the simple sequence repeats (SSRs) analysis. A total number of 138 pairs of SSRs primers covering the whole soybean genome were randomly selected for polymorphic analysis between two parents. 86 pairs of which were polymorphic and polymorphic rate is up to 62.32%. 90 polymorphic loci were found. Further analysis with polymorphic SSRs loci on the sampled lines indicated that not only segregation of most SSRs loci conformed to the ratio of 1:1, but also almost each sampled line tended to homozyge. The distribution of genotypic composition was normal. The population is ideal for genetic mapping and other genomic research.

[QTLs mapping of some agronomic traits of soybean]

A recombinant inbred population of soybean was developed from a intraspecies cross of Kefeng1 and Nannong 1138-2. A genetic linkage group of soybean genome was constructed, which composed of 22 linkage groups, included 302 loci, covered 2,363.8 cM. The interval mapping was used to identify quantitative trait loci (QLTs) associated with ten important agronomic traits in the RIL population. The results indicated that thirty-four QTLs were detected for the ten traits associated with yield and seed quality. We conclude that QTL analysis offers a useful tool for the genetic improvement of soybean cultivars.

[Phylogenetic analysis of interspecies in genus Glycine through SSR markers]

The genetic diversity among 11 species of genus Glycine (altogether 37 accessions) was evaluated through SSR analysis. The number of alleles in different loci ranges from 6 to 29, averaging 15.9 per locus; alleles of subgenus soja account for 71.5% of those in subgenus Glycine, and the fingerprinting among subgenus Glycine is more divergent than that of subgenus soja. Principal factor analysis shows that the first and the second principal factor can classify genus Glycine into two groups which represent subgenus Glycine and subgenus soja. The results of UPGMA indicate that G. mas, G. soja and G. gracilis in subgenus soja are different species.

Proteasome inhibitors block intracellular growth and replication of Toxoplasma gondii

Lactacystin, a specific inhibitor of proteasomes in eukaryotic cells, did not block parasite entry or the establishment of the parasitophorous vacuole, but did inhibit parasite growth and daughter cell budding, as well as DNA synthesis. Two other proteasome inhibitors, MG-132 and proteasome inhibitor 1, also blocked parasite growth and intracellular development. Adding lactacystin to established, dividing parasites, rapidly blocked parasite growth and daughter cell budding at all stages in the process. Pre-treating host cells with lactacystin did not block parasite entry or development. Moreover, under the conditions used, the host cells appeared not to be adversely affected indicating that host cell proteasome activity was not essential for parasite entry or development. Concomitant with these effects on parasite growth and division were morphological changes in the parasite including the appearance of whorls of ER-derived membranes presumably related to the failure to breakdown misfolded proteins. These changes were specific to lactacystin and were not seen in parasites treated with other protease inhibitors. Although the ER-derived structures resembled autophagic bodies, similar structures could not be induced by serum starvation nor did the membranous whorls acidify or undergo morphological changes consistent with autophagosomal maturation. These results highlight the possible role of proteasome activity in Toxoplasma in intracellular development and the regulation of parasite replication. However, how the dividing parasite recycles its organelles and the functional relationship between any lysosomal autophagic pathway and proteasomes in the parasite remains unresolved.

Inhibition of NF-kappaB activation in combination with bcl-2 expression allows for persistence of first-generation adenovirus vectors in the mouse liver

NF-kappaB is a key regulator of the innate antiviral immune response, due in part to its transcriptional activation of cytokines and adhesion molecules, which, in turn, function in chemotaxis and activation of inflammatory cells. We reported earlier that viral gene expression in hepatocytes transduced with first-generation (E1-deleted) adenoviruses induced NF-kappaB activation, elevation of serum cytokines, and hepatocellular apoptosis during the first days postinfusion. These events did not occur in mice infused with an adenovirus vector deleted for E1, E2, E3, and late gene expression. In the present study, we used an adenovirus expressing an IkappaBalpha supersuppressor (Ad.IkappaBM) and bcl-2 transgenic mice to unravel the role of virus-induced NF-kappaB activation and apoptosis in the clearance of recombinant adenovirus vectors from the liver. The combined action of IkappaBM and Bcl-2 allowed for vector persistence in livers of C57BL/6 x C3H mice. In the absence of Bcl-2, IkappaBM expression in mouse livers significantly reduced NF-kappaB activation, cytokine expression, leukocyte infiltration, and the humoral immune response against the transgene product; however, this was not sufficient to prevent the decline of vector DNA in transduced cells. Infusion of Ad.IkappaBM caused extended apoptosis predominantly in periportal liver regions, indicating that NF-kappaB activation may protect transduced hepatocytes from apoptosis induced by adenovirus gene products. To confer vector persistence, bcl-2 transgene expression was required to block virus-induced apoptosis if NF-kappaB protection was inactivated by IkappaBM. Expression of gene products involved in early stages of apoptotic pathways was up-regulated in response to virus infusion in bcl-2 transgenic mice, which may represent a compensatory effect. Our study supports the idea that the suppression of innate defense mechanisms improves vector persistence.

Expression, selection, and organellar targeting of the green fluorescent protein in Toxoplasma gondii

We have engineered a mutant version of the green fluorescent protein GFP (Cormack et al. Selected for bright fluorescence in E. coli. Gene 1996;173:33-38) for expression in the protozoan parasite Toxoplasma gondii. Although intact GFP was not expressed at any detectable level, GFP fusion proteins could be detected by fluorescence microscopy, flow cytometry (FACS), and immunoblotting. Both extracellular tachyzoites and T. gondii-infected host cells could readily be sorted by FACS, which should facilitate a variety of selection strategies. Several selectable markers were tested for their ability to produce stable green transgenic parasites. Fluorescence intensity was directly correlated with gene copy number and protein expression level. Weak selectable markers such as chloramphenicol acetyl transferase (CAT) driven by the SAG1 promoter, which yield multicopy insertions, are therefore most effective for selecting green fluorescent parasites-particularly when coupled to constructs which employ a strong promoter to drive GFP expression. Transformation vectors developed in the course of this work should be of general utility for the overexpression of heterologous transgenes in Toxoplasma. CAT-GFP fusion proteins were expressed in the parasite cytoplasm. GFP fusions to the P30 major surface antigen (linked on the same plasmid to a CAT selectable marker under control of various promoters) could be detected in dense granules within living cells, and were efficiently secreted into the parasitophorous vacuole. GFP fusions to the rhoptry protein ROP1 were targeted to rhoptries (specialized secretory organelles at the apical end of the parasite).

Zonal differences in DNA synthesis activity and cytochrome P450 gene expression in livers of male F344 rats treated with five nongenotoxic carcinogens

Both increased cell proliferation and "altered" CYP gene expression are prominent phenomena associated with liver tumor promotion by nongenotoxic carcinogen treatment. To further characterize these two responses, groups of rats were kept on powdered rat chow diet containing 0.05% phenobarbital (PB) or 0.025% ciprofibrate (Cip) for 8 days or given 8 daily doses by gavage of pregnenolone 16 alpha-carbonitrile (PCN, 150 mg/kg/ml corn oil), 3,3',4,4'-tetrachlorobiphenyl (PCB-MC, 3 mg/kg/ml corn oil) or 2,2',4,4'-tetrachlorobiphenyl (PCB-PB, 7.5 mg/kg/ml corn oil). A minipump was implanted in the rat abdominal cavity to release bromodeoxyuridine (BRDU) 5 days after the start of nongenotoxic carcinogen treatment and the experiment was terminated 3 days later. BRDU-labeled parenchymal nuclei were observed primarily in the periportal area independent of nongenotoxic carcinogen treatment. Treatment with each of the 5 nongenotoxic carcinogens resulted in profound alterations in CYP gene expression at both the transcriptional and translational levels. Expression of CYP1A1, 1A1/2, 3A1, 2B1/2, and 4A immunoproteins demonstrated nongenotoxic carcinogen-specific patterns in both magnitude and zonal distribution. In agreement with the CYP immunoprotein data, treatment with each of the five nongenotoxic carcinogens resulted in a unique composition of mRNAs of CYP2B1, 2B2, 2C6, 2C11, 3A1, 3A2, and 4A1, which were variably increased or decreased relative to the untreated control livers, depending on the treatment. Similarly, the rate and pattern of CYP enzyme-mediated hydroxylation toward testosterone, 17 beta-estradiol, corticosterone, and lauric acid were greatly altered by nongenotoxic carcinogen treatment. According to the zonal distribution patterns of CYP immunoproteins, each hepatocyte in the cell plate from the periportal triad to the central vein has a characteristic and nongenotoxic carcinogen-specific composition of CYP enzymes. Because many endogenous substrates are modulators of DNA and RNA synthesis, intracellular kinetics of endogenous substrates of CYP enzymes in the corresponding hepatocytes could contribute, at least in part, to the differences in gene expression, differentiation, and cell proliferation among the hepatocytes in the cell plate.

Adenoviral preterminal protein stabilizes mini-adenoviral genomes in vitro and in vivo

In the absence of host immunity, nonintegrating, first-generation adenoviral vectors remain stable in the nucleus of quiescent transduced cells in mice. A mini-adenoviral genome (9 kb) deleted for viral E1, E2, E3, and late genes, but containing the viral inverted terminal repeats (ITRs), transgene expression cassette (human alpha 1-antitrypsin), and the viral E4 genes was equally efficient at transducing cells in vitro or in vivo as first generation, E1-deleted vectors. In contrast to a first generation vector, gene expression as well as vector DNA was short-lived in cells transduced with the deleted adenoviral genome. We demonstrate that coexpression of the adenoviral E2-preterminal protein from the vector or in trans stabilizes the mini-genome in vitro and in vivo without evidence of cellular toxicity.

The role of Kupffer cell activation and viral gene expression in early liver toxicity after infusion of recombinant adenovirus vectors

Systemic application of first-generation adenovirus induces pathogenic effects in the liver. To begin unraveling the mechanisms underlying early liver toxicity after adenovirus infusion, particularly the role of macrophage activation and expression of viral genes in transduced target cells, first-generation adenovirus or adenovirus vectors that lacked most early and late gene expression were administered to C3H/HeJ mice after transient depletion of Kupffer cells by gadolinium chloride treatment. Activation of NF-kappaB, and the serum levels of the proinflammatory cytokines tumor necrosis factor (TNF) and interleukin-6 (IL-6) were studied in correlation with liver damage, apoptosis, and hepatocellular DNA synthesis. While Kupffer cell depletion nearly eliminated adenovirus-induced TNF release, it resulted in a more robust IL-6 release. These responses were greatly reduced in animals receiving the deleted adenovirus. Although there were quantitative differences, NF-kappaB activation was observed within minutes of first-generation or deleted adenovirus vector administration regardless of the status of the Kupffer cells, suggesting that the induction is related to a direct effect of the virus particle on the hepatocyte. Early liver toxicity as determined by serum glutamic-pyruvic transaminase elevation and inflammatory cell infiltrates appeared to be dependent on adenovirus-mediated early gene expression and intact Kupffer cell function. Kupffer cell depletion had little effect on adenovirus-mediated hepatocyte apoptosis but did increase hepatocellular DNA synthesis. Finally, Kupffer cell depletion decreased the persistence of transgene (human alpha1-antitrypsin [hAAT]) expression that was associated with a more pronounced humoral immune response against hAAT. The elucidation of these events occurring after intravenous adenovirus injection will be important in developing new vectors and transfer techniques with reduced toxicity.

Elimination of hepatitis C virus RNA in infected human hepatocytes by adenovirus-mediated expression of ribozymes

Hepatitis C virus (HCV), a positive-strand RNA virus, is the major infectious agent responsible for causing chronic hepatitis. Currently, there is no vaccine for HCV infection, and the only therapy for chronic hepatitis C is largely ineffective. To investigate new genetic approaches to the management of HCV infection, six hammerhead ribozymes directed against a conserved region of the plus strand and minus strand of the HCV genome were isolated from a ribozyme library, characterized, and expressed from recombinant adenovirus vectors. The expressed ribozymes individually or in combination were efficient at reducing or eliminating the respective plus- or minus-strand HCV RNAs expressed in cultured cells and from primary human hepatocytes obtained from chronic HCV-infected patients. This study demonstrates the potential utility of ribozyme therapy as a strategy for the treatment of hepatitis C virus infection.

Recombinant adenoviruses with large deletions generated by Cre-mediated excision exhibit different biological properties compared with first-generation vectors in vitro and in vivo

In vivo gene transfer of recombinant E1-deficient adenoviruses results in early and late viral gene expression that elicits a host immune response, limiting the duration of transgene expression and the use of adenoviruses for gene therapy. The prokaryotic Cre-lox P recombination system was adapted to generate recombinant adenoviruses with extended deletions in the viral genome (referred to here as deleted viruses) in order to minimize expression of immunogenic and/or cytotoxic viral proteins. As an example, an adenovirus with a 25-kb deletion that lacked E1, E2, E3, and late gene expression with viral titers similar to those achieved with first-generation vectors and less than 0.5% contamination with E1-deficient virus was produced. Gene transfer was similar in HeLa cells, mouse hepatoma cells, and primary mouse hepatocytes in vitro and in vivo as determined by measuring reporter gene expression and DNA transfer. However, transgene expression and deleted viral DNA concentrations were not stable and declined to undetectable levels much more rapidly than those found for first-generation vectors. Intravenous administration of deleted vectors in mice resulted in no hepatocellular injury relative to that seen with first-generation vectors. The mechanism for stability of first-generation adenovirus vectors (E1a deleted) appeared to be linked in part to their ability to replicate in transduced cells in vivo and in vitro. Furthermore, the deleted vectors were stabilized in the presence of undeleted first-generation adenovirus vectors. These results have important consequences for the development of these and other nonintegrating vectors for gene therapy.

Inhibition of cell proliferation by ciprofibrate in glutathione S-transferase P1-1-positive rat hepatic hyperplastic nodules

Previous studies have demonstrated that short-term treatment with a peroxisome proliferator (PP) decreased the size and number of genotoxic carcinogen-induced hepatic hyperplastic lesions identified by gamma-glutamyl transpeptidase (GGT) or glutathione S-transferase P1-1 (rGSTP1-1) staining. However, longer-term PP treatment of animals bearing similar hepatic hyperplastic lesions produced an increase in both the size and number of liver tumors. To characterize the hepatic hyperplastic lesions which are inhibited or promoted by PP, a unique double labeling technique was developed to determine the relative rate of cell division (e.g., DNA synthesis) in rGSTP1-1-positive nodules before and after ciprofibrate (Cip) treatment. rGSTP1-1-positive nodules were induced with the Solt-Farber resistance protocol (diethylnitrosamine-2-acetylaminofluorene partial hepatectomy). Eleven weeks after diethylnitrosamine initiation, 3 groups of rats were maintained on a control chow diet or switched to a powdered chow diet containing 0.025% Cip or 0.05% phenobarbital (PB) for the last 8 days of the experiment. A minipump implanted in the abdominal cavity released [methyl-3H]thymidine continuously for 72 h and was then removed prior to CIp or PB treatment. A second minipump was then implanted which released bromodeoxyuridine to the abdominal cavity 5 days after the start of Cip or PB administration and lasted for 72 h until the termination of the experiment. Both the [methyl-3H]thymidine and bromodeoxyuridine labeling indices (LIs) were determined in the same group of cells within individual rGSTP1-1-positive nodules in the right posterior lobes of livers. PB treatment increased both the average number of persistent GGT-positive nodules and the ratio of persistent GGT-positive to rGSTP1-1-positive nodules/cm2. In contrast, Cip treatment greatly decreased the average number and area of persistent GGT-positive nodules, as well as the ratio between persistent GGT-positive and rGSTP1-1-positive nodules/cm2. Cip treatment also resulted in a 40% decrease in the average LI in the rGSTP1-1-positive nodules. In some rGSTP1-1-positive nodules, the LI was decreased from > 40% prior to Cip treatment to < 5% afterward, suggesting that Cip treatment interrupted progression in these nodules. Such drastic changes in the LI before and after treatments were not observed in either PB- or vehicle-treated (control) animals. A number of small nodules with a high bromodeoxyuridine LI but with no or very few [methyl-3H]thymidine-labeled nuclei and negative GGT and rGSTP1-1 staining were detected only in the Cip group.(ABSTRACT TRUNCATED AT 400 WORDS)

[Effect of elevated plasma norepinephrine on electrocardiographic changes in subarachnoid hemorrhage]

We compared electrocardiographic abnormalities and plasma norepinephrine concentration in 40 patients with subarachnoid hemorrhage within the first 24 hours, at 72 hours, and after 1 week. In the 20 patients with high plasma norepinephrine concentrations within the first 24 hours, sinus tachycardia and negative T waves were more frequently seen than in the 20 patients with normal plasma norepinephrine concentrations. After 72 hours, only sinus tachycardia was found with increased frequency in the 26 patients with high plasma norepinephrine concentrations. Although 24 patients had high plasma norepinephrine concentrations after 1 week, we found no difference in the frequency of electrocardiographic abnormalities as compared with patients with normal plasma norepinephrine. QT prolongation, U waves, ST depression, and arrhythmias were found with similar frequency in patients with high and normal plasma norepinephrine concentrations. We conclude that, with the exception of sinus tachycardia and negative T waves, other electrocardiographic changes in patients with subarachnoid hemorrhage do not depend on elevated plasma norepinephrine concentrations.

Comparison of 14C-amino acid mixture and [35S]methionine labeling of cellular proteins from mouse fibroblast C3H10T1/2 cells by two-dimensional gel electrophoresis

Total cellular proteins from mouse C3H10T1/2 fibroblasts were compared by two-dimensional (2-D) gel electrophoresis after radiolabeling with [35S]methionine (35S-Met) or 14C-amino acids (14C-AA). 35S-Met labeling of protein was three to four times greater than 14C-AA incorporation over a 24 h period. Automated comparative analysis of replicate fluorographs after 6, 12, and 24 h of labeling showed considerable homology between radiolabeling methods. More than 88% percent of 35S-Met and 14C-AA-labeled proteins were common at each time point. However, the total number of 35S-Met-labeled proteins dropped from 6 to 24 h while the number of 14C-AA-labeled proteins increased. Additionally, twenty-one proteins were uniquely labeled by 14C-AA that were not detectable by 35S-Met over the labeling period. Densitometric analysis showed that several 35S-Met and 14C-AA-labeled proteins exhibited time-related differences in radiolabel incorporation while most proteins remained relatively constant. Protein patterns of silver-stained gels from 6 to 24 h were highly registered and showed few qualitative differences. Proteins detected in radiolabeled gels were generally, but not always, found in silver-stained gels. Thus, 35S-Met appears better suited for short-term radiolabeling of cellular protein while more comprehensive labeling of protein occurs with 14C-AA during prolonged incubation of cell cultures under present experimental conditions.