Discovery of tricyclic PARP7 inhibitors with high potency, selectivity, and oral bioavailability

PARP7 has been recently identified as an effective drug target due to its specific role in tumor generation and immune function recovery. Herin, we report the discovery of compound 8, which contained a tricyclic fused ring, as a highly selective PARP7 inhibitor against other PARPs. In particular, compound 8 strongly inhibits PARP7 with an IC50 of 0.11 nM, and suppresses the proliferation of NCI-H1373 lung cancer cells with an IC50 of 2.5 nM. Compound 8 exhibits a favorable pharmacokinetic profile with a bioavailability of 104 % in mice, and 78 % in dogs. Importantly, daily treatment of 30 mg/kg of 8 induced 81.6 % tumor suppression in NCI-H1373 lung xenograft mice tumor models, which is significantly better than the clinical candidate, RBN-2397. These intriguing features highlight the promising advantages of 8 as an antitumor agent.

Identification of a Sonically Activated Degrader of Methionine Adenosyltransferase 2A by an in Silico Approach Assisted with the Hole-Electron Analysis

Small molecules capable of modulating methionine adenosyltransferase 2A (MAT2A) are of significant interest in precise cancer therapeutics. Herein, we raised the hole-electron Coulombic attraction as a reliable molecular descriptor for predicting the reactive oxygen generation capacity of MAT2A inhibitors, based on which we discovered compound H3 as a sonically activated degrader of MAT2A. Upon sonication, H3 can generate reactive oxygen species to specifically degrade cellular MAT2A via rapid oxidative reactions. Combination of H3 and sonication induced 87% MAT2A depletion in human colon cancer cells, thus elevating its antiproliferation effects by 8-folds. In vivo, H3 had a favorable pharmacokinetic profile (bioavailability = 77%) and ADME properties. Owing to the MAT2A degradation merits, H3 at a dosage of 10 mg/kg induced 31% tumor regression in xenograft colon tumor models. The significantly boosted antitumor potency can potentially alleviate the toxicity of high-dose MAT2A inhibitors to normal cells and tissues, especially to the liver.

Exploring the structural-activity relationship of hexahydropyrazino[1,2-d]pyrido[3,2-b][1,4]oxazine derivatives as potent and orally-bioavailable PARP7 inhibitors

PARP7 has emerged as a promising anti-tumor target due to its crucial roles in nucleic acid sensing and immune regulation. Herein, we explored the structural-activity relationship of tricyclic PARP7 inhibitors containing a hexahydropyrazino[1,2-d]pyrido[3,2-b][1,4]oxazine motif. The effects of the chirality of the fused rings, the group conjugated to the fused rings, and the size of the linker on PARP7 inhibition were fully investigated. Our work leads to the discovery of an extremely potent and orally-bioavailable PARP7 inhibitor, namely 18 (PARP7 inhibition IC50 = 0.56 nM), for efficacious treatment of lung cancer in vivo. Notably, 18 showed acceptable bioavailability in ICR mice (F = 33.9%) and Beagle dogs (F = 45.2%). Further investigation of ADME-T properties suggested that 18 has the potential to be developed as a candidate drug molecule for PARP7-sensitive tumors.

Design of Orally-bioavailable Tetra-cyclic phthalazine SOS1 inhibitors with high selectivity against EGFR

KRAS mutations (G12C, G12D, etc.) are implicated in the oncogenesis and progression of many deadliest cancers. Son of sevenless homolog 1 (SOS1) is a crucial regulator of KRAS to modulate KRAS from inactive to active states. We previously discovered tetra-cyclic quinazolines as an improved scaffold for inhibiting SOS1-KRAS interaction. In this work, we report the design of tetra-cyclic phthalazine derivatives for selectively inhibiting SOS1 against EGFR. The lead compound 6c displayed remarkable activity to inhibit the proliferation of KRAS(G12C)-mutant pancreas cells. 6c showed a favorable pharmacokinetic profile in vivo, with a bioavailability of 65.8% and exhibited potent tumor suppression in pancreas tumor xenograft models. These intriguing results suggested that 6c has the potential to be developed as a drug candidate for KRAS-driven tumors.

Design and Structural Optimization of Methionine Adenosyltransferase 2A (MAT2A) Inhibitors with High In Vivo Potency and Oral Bioavailability

Inhibition of methionine adenosyltransferase 2A (MAT2A) in cancers with a deletion of methylthioadenosine phosphorylase (MTAP) gene leads to synthetic lethality, thus receiving significant interest in the field of precise cancer treatment. Herein, we report the discovery of a tetrahydrobenzo[4,5]imidazo[1,2-a]pyrazine fragment which occupies the MAT2A allosteric pocket. The lead compound 8 exhibited extremely high potency to inhibit MAT2A enzymatic activity (IC₅₀ = 18 nM) and proliferation of MTAP-null cancer cells (IC₅₀ = 52 nM). 8 had a favorable pharmacokinetic profile with a bioavailability of 116% in mice. More importantly, introducing an amide motif (28) to the core structure raised the plasma drug exposure from 11 718 to 41 192 ng·h·mL^-1. 28 displayed a significantly better in vivo potency than AG-270, which is being evaluated in clinical trails, and induced -52% tumor regression in a xenograft MTAP-depleted colon tumor model.

Targeted Recruitment and Degradation of Estrogen Receptor α by Photothermal Polydopamine Nanoparticles for Breast Tumor Ablation

The major challenges of photothermal therapy (PTT) toward clinical application are the severe skin injury and inflammation response associated with high power laser irradiation. Herein, polydopamine nanoparticles (PDA-EST and PDA-RAL) targeted to estrogen receptor α (ERα) for efficient ablation of breast tumor under a low irradiation density of 0.1 W cm^-2 are reported. These nanoparticles are capable of recruiting ERα on their surface and induce a complete ERα degradation via localized heat. Owing to the ERα targetability, PDA-EST and PDA-RAL strongly suppress the proliferation of breast cancer cells without causing significant inflammation. This work provides a generalized method for enhancing PTT efficacy under low irradiation density.

AB0347 INCREASING TO OPTIMAL METHOTREXATE DOSE MIGHT BE A BETTER TRADITIONAL DMARD STRATEGY IN RA TREATMENTS: A RANDOMIZED CASE-CONTROL TRIAL OF HAKKA PEOPLE IN SOUTHERN CHINA

Background:

The optimal methotrexate (MTX) dose is defined as 0.3mg/kg/week or ≥ 20mg/week at 6 months. [1] Considering average weight of Chinese, [2] the optimal MTX should be >15mg/w. However, not more than 30% in 25191 RA cases ever had MTX treatment in CREDIT (Chinese Registry of Rheumatoid arthritis). [3] The biggest concern is side effects of MTX. Our study is to investigate whether increasing MTX would get better results accompanied with more side effects to Chinese people.

Objectives:

Hakka people have the purest genes of the majority people-Han in China. It is planned to recruit 160 RA patients in Meizhou, where is a gathering place of Hakka people.

Methods:

The RA volunteers had no relief with 10 mg/w oral dose of MTX with/without other 1-2 inadequate dose of DMARDs for at least 3 months. They were randomly divided into 1:1 groups*. The experimental group would be treated with original DMARDs and incremental MTX (gradually increased to the optimal oral dose (0.3 mg/k/w) in the first 12 weeks and folic acid (the dose adjusted on demand with range from 5 mg/w to 5mg tid). While the control group would be treated with original MTX dose(10mg/w) but incremental original DMARDs(gradually increased to the maximum dose in the first 12 weeks). The two groups would keep the treatment at 12thweek last to the 36thweek, and the efficacy and safety indexes would be evaluated during the whole study.

Results:

1)We planned to recruit 160 RA patients in our study. 46 Hakka RA patients were enrolled in the study so far. 2 of 46 finished the 24thweek visit and 24 finished the 36thweek visit. The average age is 54.2± 9.3 years old, the average weight is 59.1±11.1kg, and the female to male ratio is 41:5.

2)The average Folic acid dose is 14.4±9.5mg/w in the experimental group at the 12thweek.

3)The morning stiffness time, PGA, PhGA, HAQ, DAS28 were better in experimental group after 12 weeks though slightly worse during 0-12 weeks. 100%(12) patients in experimental group, while 66.67%(8/12) in control group reach ACR20.

4) Only 1 case(5.9%,1/23)had adverse event while 6 cases (26%,6/23) occurred adverse events. All events were mild level. 1 case (4.2%,1/23) in control group withdrew from the study because the disease was getting worse during 0-24 weeks.

Conclusion:

Hakka patients in China might have better outcomes due to increasing MTX to the 0.3mg/kg/w dose than increasing the other DMARDs. Therefore, We recommended the Chinses patients choose MTX as first incremental DMARD. The appropriate dose of Folic acid plus with the optimal dose of MTX in our study is higher than previous studies (such as 13.0±4.8mg/w reported by Gaujoux-Viala, 2018[1]). We recommended Chinese patients take 15mg/w folic acid to prevent MTX side effects in view of lower folic acid level in Chinese population.[3]

References:

[1]Gaujoux-Viala C, Rincheval N, Dougados M, et al. Optimal methotrexate dose is associated with better clinical outcomes than non-optimal dose in daily practice: results from the ESPOIR early arthritis cohort. Ann Rheum Dis. 2017 Dec;76(12):2054-2060.

[2]Nan Jiang, Mengtao Li, Yanhong Wang, et al. Baseline characteristics and treatments among patients with rheumatoid arthritis: the CREDIT study in China, 2016-2018. Ann Rheum Dis. 2019 Jun; 78 (Suppl 2) 1404-1405.

[3]He Y, Pan A, Hu FB,et al. Folic acid supplementation, birth defects, and adverse pregnancy outcomes in Chinese women: a population-based mega-cohort study, Lancet, 2016 Oct,Volume 388, Number 1, pp. S91-S91-(1)

Disclosure of Interests:

None declared

Activation of the STING-IRF3 pathway promotes hepatocyte inflammation, apoptosis and induces metabolic disorders in nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common result of obesity and metabolic syndrome. Hepatocyte injury and metabolic disorders are hallmarks of NAFLD. Stimulator of interferon genes (STING) and its downstream factor interferon regulatory factor 3 (IRF3) trigger inflammatory reaction in response to the presence of cytosolic DNA. STING has recently been shown to play an important role in early alcoholic liver disease. However, little is known about the role of STING-IRF3 pathway in hepatocyte injury. Here, we aimed to examine the effect of STING-IRF3 pathway on hepatocyte metabolism, inflammation and apoptosis.

METHODS

We examined the activation of the STING-IRF3 pathway, a high-fat diet (HFD)-induced obese mouse model, and determined the role of this pathway in a free fatty acid (FFA)-induced hepatocyte inflammatory response, injury, and dysfunction in L-O2 human liver cells.

RESULTS

STING and IRF3 were upregulated in livers of HFD-fed mice and in FFA-induced L-O2 cells. Knocking down either STING or IRF3 led to a significant reduction in FFA-induced hepatic inflammation and apoptosis, as evidenced by modulation of the nuclear factor κB (NF-κB) signaling pathway, inflammatory cytokines, and apoptotic signaling. Additionally, STING/IRF3 knockdown enhanced glycogen storage and alleviated lipid accumulation, which were found to be associated with increased expression of hepatic enzymes in glycolysis and lipid catabolism, and attenuated expression of hepatic enzymes in gluconeogenesis and lipid synthesis.

CONCLUSIONS

Our results suggest that the STING-IRF3 pathway promotes hepatocyte injury and dysfunction by inducing inflammation and apoptosis and by disturbing glucose and lipid metabolism. This pathway may be a novel therapeutic target for preventing NAFLD development and progression.

Sensitivity of various body indices and visceral adiposity index in predicting metabolic syndrome among Chinese patients with adult growth hormone deficiency

AIM

Adult growth hormone deficiency (AGHD) refers to decreased secretion of growth hormones in the adults, which is associated with increased clustering of conventional cardiovascular risk factors such as central obesity, insulin resistance and dyslipidemia. Metabolic syndrome (MetS), a recognized risk factor of cardiovascluar diseases, shares some clinical features. Given that the prevalence of MetS is on the rise in patients with AGHD, and that cardiovascular disease (CVD) is an important cause of morbidity and mortality in that population, the alternative, simple, non-invasive methods of assessing MetS among this population are needed. This study aims to determine the sensitivity of five anthropometric indices [Body mass index (BMI), Waist circumference (WC), Waist-to-hip ratio (WHR), Waist-to-height ratio (WHtR) and Visceral adiposity index (VAI)] in predicting metabolic syndrome in Chinese population-based patients with adult growth hormone deficiency.

MATERIALS AND METHODS

A total of 96 Chinese patients with adult growth hormone deficiency were included in this study. They were compared with equal number of apparently healthy persons with similar characteristics (matched with age and gender) to the previous group. Anthropometric measurements including weight, height, serum lipids indices, blood pressure (BP), fasting plasma glucose (FPG), WC were measured. BMI, WHR, WHtR, and VAI were calculated.

RESULTS AND DISCUSSION

AGHD patients with MetS had higher WC (91.00 ± 8.28 vs 78.01 ± 7.12), BMI (24.95 ± 2.91 VS 23.30 ± 2.80), WHR (0.92 ± 0.06 VS 0.87 ± 0.07), WHtR (0.53 ± 0.06 VS 0.47 ± 0.05), VAI [(5.59 (4.02, 7.55) VS 1.69 (0.87, 3.05)] levels in comparison to those without MetS. Meantime WC, BMI, WHR, WHtR, VAI was positively correlated to MetS components. ROC curve for participants with AGHD showed that VAI had the highest SS of 92% (BMI 0.812; WHR 0.706; WHtR 0.902; VAI 0.920, respectively) for prediction of MetS in AGHD. The optimal cutoff values for different adiposity markers in predicting MetS were as follows: WC (79.65), BMI (23.46); WHR (0.89); WHtR (0.54); VAI (2.29).

CONCLUSION

In conclusion, our study showed all adiposity measures of interest present themselves as easy and practical tools for use in population studies and clinical practice for evaluating MetS in AGDH and VAI was identified as the best in Chinese AGHD patients among them.

Outdoor, indoor, and personal black carbon exposure from cookstoves burning solid fuels

Black carbon (BC) emissions from solid fuel combustion are associated with increased morbidity and mortality and are important drivers of climate change. We studied BC measurements, approximated by particulate matter (PM2.5 ) absorbance, in rural Yunnan province, China, whose residents use a variety of solid fuels for cooking and heating including bituminous and anthracite coal, and wood. Measurements were taken over two consecutive 24-h periods from 163 households in 30 villages. PM2.5 absorbance (PMabs ) was measured using an EEL 043 Smoke Stain Reflectometer. PMabs measurements were higher in wood burning households (16.3 × 10(-5) /m) than bituminous and anthracite coal households (12 and 5.1 × 10(-5) /m, respectively). Among bituminous coal users, measurements varied by a factor of two depending on the coal source. Portable stoves (which are lit outdoors and brought indoors for use) were associated with reduced PMabs levels, but no other impact of stove design was observed. Outdoor measurements were positively correlated with and approximately half the level of indoor measurements (r = 0.49, P < 0.01). Measurements of BC (as approximated by PMabs ) in this population are modulated by fuel type and source. This provides valuable insight into potential morbidity, mortality, and climate change contributions of domestic usage of solid fuels.

Lipid Accumulation Product: a Simple and Accurate Index for Predicting Metabolic Syndrome in Patients with Adult Growth Hormone Deficiency

PURPOSE

It has been demonstrated that metabolic risk factors were increased in adult growth hormone deficiency (AGHD) patients. Lipid accumulation product (LAP) is a novel biomarker of central lipid accumulation related to risk of metabolic syndrome (MS), diabetes and cardiovascular disease. The aim of this study was to investigate the ability of LAP to identify MS in AGHD Patients.

MATERIALS AND METHODS

In this cross-sectional study, 75 AGHD patients and 75 controls matched with age and gender were enrolled. The general anthropometries and blood biochemical indexes were measured. Body mass index(BMI), waist-hip ratio (WHR), LAP, HOMA-IR were calculated. Receiver operating characteristic (ROC) analysis was used to find out the cut-off points of LAP to predict MS.

RESULTS

Compared with control group, waist circumference (WC), WHR, Systolic blood pressure (SBP), Diastolic blood pressure (DBP), total cholesterol (TC), triglyceride (TG) and LAP were increased in AGHD group, while high density lipoprotein cholesterol (HDL-c) level was lower in AGHD group (P<0.05). The prevalence of MS was 41.3% in AGHD patients. AGHD patients with MS had significantly higher LAP levels compared to those without MS. LAP was highly correlated with components of MS. ROC analysis showed that LAP was a significant discriminator for MS in AGHD patients, and the optimal cutoff point of LAP to predict MS was 44.96 (96.8% sensitivity, 86.4% specificity).

CONCLUSIONS

LAP was associated with MS and had a strong and reliable diagnostic accuracy for MS in AGHD patients.

Construction of conditionally replicating adenovirus expressing staphylococcal enterotoxin A gene: potential usefulness for anti-tumor therapies

OBJECTIVE

The aim of this study was to construct a conditionally replicating adenovirus pPE3-SEA expressing staphylococcal enterotoxin A (SEA) gene.

MATERIALS AND METHODS

A full-length SEA gene fragment was cloned into pENTR12 plasmid to obtain a recombinant viral plasmid pENTR12-SEA. The pENTR12-SEA plasmid was co-transfected into HEK293 cells along with pPE3-ccdB, which encoded for the virus backbone, to generate recombinant adenovirus pPE3-SEA vector. Amplified pPE3-SEA vectors were purified, and viral titer was determined using the 50% tissue culture infective dose method.

RESULTS

The PCR, restriction enzyme digestion, and sequence analyses proved successful construction of replicating oncolytic adenovirus pENTR12-SEA and recombinant SEA expressing oncolytic adenovirus pPE3-SEA. The viral titer was 2.5 × 1010 pfu/ml.

CONCLUSIONS

We successfully constructed conditionally replicating adenovirus pPE3-SEA which can be utilized for experimental studies of tumor-targeted therapies.

Anatomic site variability in rat skeletal uptake and desorption of fluorescently labeled bisphosphonate

OBJECTIVES

Bisphosphonates commonly used to treat osteoporosis, Paget's disease, multiple myeloma, hypercalcemia of malignancy and osteolytic lesions of cancer metastasis have been associated with bisphosphonate-associated jaw osteonecrosis (BJON). The underlying pathogenesis of BJON is unclear, but disproportionate bisphosphonate concentration in the jaw has been proposed as one potential etiological factor. This study tested the hypothesis that skeletal biodistribution of intravenous bisphosphonate is anatomic site-dependent in a rat model system.

MATERIALS AND METHODS

Fluorescently labeled pamidronate was injected intravenously in athymic rats of equal weights followed by in vivo whole body fluorimetry, ex vivo optical imaging of oral, axial, and appendicular bones and ethylenediaminetetraacetic acid bone decalcification to assess hydroxyapatite-bound bisphosphonate.

RESULTS

Bisphosphonate uptake and bisphosphonate released per unit calcium were similar in oral and appendicular bones but lower than those in axial bones. Hydroxyapatite-bound bisphosphonate liberated by sequential acid decalcification was the highest in oral, relative to axial and appendicular bones (P < 0.05).

CONCLUSIONS

This study demonstrates regional differences in uptake and release of bisphosphonate from oral, axial, and appendicular bones of immune deficient rats.

Effects of cyclic AMP on development and secondary metabolites of Monascus ruber M-7

AIM

To study effects of cyclic adenosine monophosphate (cAMP) on development and secondary metabolites of Monascus ruber M-7.

METHODS AND RESULTS

Plate culture, liquid-state fermentation (LSF) and solid-state fermentation (SSF) were used to evaluate effects of cAMP on colonial growth, spore formation and polyketide production of Strain M-7. The results revealed that the variation trends of colonial sizes, numbers of sexual spores and red pigment contents of M-7 were in a dose-dependent manner. And generally they increased and decreased with cAMP concentrations in the ranges of low cAMP concentrations and high cAMP concentrations, respectively. But the variation trends of numbers of asexual spores and citrinin production in both LSF and SSF were opposite to those of colonial sizes, sexual sporulation and red pigment.

CONCLUSIONS

The regulation of cAMP on development and secondary metabolites in Strain M-7 was in a dose-dependent pattern. And red pigment might convert to citrinin under changing cAMP concentrations.

SIGNIFICANCE AND IMPACT OF THE STUDY

The effects of cAMP on Strain M-7 in SSF give a new clue to enhance beneficial polyketides and reduce citrinin produced by M. ruber.

First Report of Tobacco curly shoot virus Infecting Pepper in China

In recent years, whitefly-transmitted begomovirues (family Geminiviridae) have caused severe leaf curl disease on tobacco and tomato in southern China, but have not been found on pepper. In August 2009, pepper plants (Capsicum frutescens) grown in the field in Panzhihua City of Sichuan Province (southwestern China), from where the occurrence of begomoviruses has not been reported previously, showed stunting, leaf yellowing, and mild curling symptoms. To identify possible begomoviruses, total DNA was extracted from three infected pepper plants (SC117, SC118, and SC119) with typical symptoms. Using degenerate primer pair PA/PB specific for members of the genus Begomovirus (2), a 500-bp DNA fragment covering parts of the intergenic region and V2 gene of the genome of begomoviruses was amplified from all samples. No amplification was observed from healthy plant extracts. The PCR product from SC118 was cloned and two clones were chosen to be sequenced. Alignment of the partial DNA sequences revealed that the cloned products from isolate SC118 were nearly identical (98.5%) and most closely related to Tobacco curly shoot virus isolate Y35 (TbCSV-[China:Yunnan 35:2001]; Accession No. AJ420318) (96.9 and 97.3% identity, respectively). Therefore, the entire genome of isolate SC118 was sequenced. Overlap primers TbCSV-F(5'-CCGCCGTCTCAACTTCGACAG-3') and TbCSV-R(5'-ATCTGCTGGTCGCTTCGACAT-3') were designed to amplify the full-length genome of SC118. The complete genome sequence of SC118 was determined to be 2,746 nucleotides (Accession No. GU001879) long, with two open reading frames (ORFs) in the virion-sense strand and four ORFs in the complementary-sense strand, typical of the Old World begomoviruses. A comparison with other reported sequences of begomoviruses shows that the genome of SC118 shares the highest nucleotide sequence identity (99.7%) with TbCSV-[China:Yunnan 35:2001]. When PCR was used to detect TbCSV from the other two isolates (SC117 and SC119) with TbCSV specific primer pair Y35F1 and Y35+10R (4), which amplified the fragment covering the whole C2 and C3 genes and the partial C1 and V1 genes of the genome of TbCSV, an amplicon of approximately 1.0 kb was obtained from all samples. To determine whether a satellite molecule was associated with the three virus isolates, a universal betasatellite abutting primer pair (beta01 and beta02) was used (1). No amplification product was detected. In previous studies, it was demonstrated that only 11 isolates were associated with betasatellites among 39 TbCSV-infected, field-collected samples (3), and betasatellites could be associated with noncognate begomoviruses (4). Therefore, the three isolates examined in this study are too few to come to a conclusion that betasatellites are not associated with TbCSV infection of pepper plants. A detailed search for the presence of betasatellites needs to be conducted to draw a definitive conclusion. The above results confirmed that samples SC117, SC118, and SC119 were infected by TbCSV. To our knowledge, this is the first report of TbCSV on pepper in China. References: (1) R. W. Briddon et al. Mol. Biotechnol. 20:317, 2002. (2) D. Deng et al. Ann. Appl. Biol. 125:327, 1994. (3) Z. Li et al. Phytopathology 95:902, 2005. (4) L. Qing et al. Phytopathology 99:716, 2009.

First Report of Tobacco mosaic virus in Abutilon theophrasti in China

Velvetleaf (Abutilon theophrasti Medic), a tall, fecund, self-fertile annual plant in the family Malvaceae, is widely grown in China as a fiber crop and for its medicinal properties. In July of 2008, we observed diffuse chlorotic and necrotic spots on the oldest leaves of velvetleaf plants in the field in Shanxi Province. Sap extracts from six symptomatic plants were tested by direct antigen coated ELISA using polyclonal antibodies specific to Potato virus Y (PVY) and monoclonal antibodies specific to Tomato mosaic virus (ToMV), Cucumber mosaic virus (CMV), and Tobacco mosaic virus (TMV). Five of the six samples were negative for ToMV, CMV, and PVY but positive for TMV. Double-stranded RNA extracted from leaves of the five velvetleaf plants was used as template for reverse transcription (RT)-PCR as described by Krajačića et al. (1) and Li et al. (2) with some modifications. One-step RT-PCR was performed using a Quant One Step RT-PCR Kit (TIANGEN BIOTECH CO., LTD., Beijing, China) with sense (5'-CTGTTTAGCCGGTTTGGT-3'), and antisense (5'-TCCCTTTACGGACATCAC-3') primers (3) designed to specifically amplify a fragment of the movement protein coding region of TMV. The expected 470-bp fragments were amplified from dsRNA from these five plants and the amplicon from each plant was cloned and sequenced (GenBank Accession No. FJ873800). Comparisons of a consensus sequence derived from the five amplicons with the nucleotide sequences available in the NCBI database using BLAST showed 99% identity with TMV from South Korea (GenBank Accession No. AB354955) and Spain (Accession No. AJ308692) and 98% with TMV from China (Accession No. AF165190). The serological, RT-PCR results and sequence data revealed that these velvetleaf plants were infected by TMV. On the basis of the serological analysis and genome sequence comparisons, this isolate was tentatively designated as TMV-Velvetleaf. To our knowledge, this is the first report of TMV in Abutilon theophrasti Medic in China. References: (1) M. Krajačić et al. J. Chromatogr A. 1144:111, 2007. (2) H. Li et al. Agric. Sci. Chin. 6:86, 2007. (3) Y. B. Niu et al. Chin. Biotechnol. 29:76, 2009.

The recombinant nonstructural polyprotein NS1 of porcine parvovirus (PPV) as diagnostic antigen in ELISA to differentiate infected from vaccinated pigs

To differentiate pigs infected with porcine parvovirus (PPV) from those vaccinated with inactivated whole-virus vaccine, an enzyme-linked immunosorbent assay (ELISA) based on detection of a nonstructural polyprotein 1 (NS1) was developed. A threshold of 0.23 optical density units was established and the assay had high specificity (100), sensitivity (88), accuracy (90) and positive predictive value (100) using haemagglutination inhibition as the standard method. A reproducibility test revealed that the coefficients of variation of sera within-plates and between-run were less than 10%. The assay showed no cross-reactivity with antibodies to porcine reproductive respiratory syndrome virus, pseudorabies virus, foot and mouth disease virus, Actinobacillus pleuropneumoniae, Toxoplasma or Chlamydia. Sera obtained from pigs infected with PPV reacted with recombinant NS1 protein in the ELISA. Sera from pigs vaccinated with inactivated whole virus did not recognize this protein in the ELISA. In contrast, antibodies against PPV whole virus were present in both PPV-infected and vaccinated animals. Serum conversion against NS1 was first detected 10 days after infection and NS1-specific antibodies were detectable up to half a year post infection. In conclusion, the PPV-NS1 ELISA can differentiate PPV-infected versus inactivated PPV-vaccinated pigs and could be applied in disease diagnosis and surveillance.

OxLDL upregulates growth-regulation oncogene alpha expression in human endothelial cells

OBJECTIVE

To explore the effect of oxLDL on CXC chemokine growth-regulated oncogene alpha (GRO alpha) expression in human endothelial cells and the possible functional significance of the effect.

METHODS

LDL was isolated by sequential ultracentrifugation and oxidized to oxLDL. Reverse transcription-polymerase chain reaction with GAPDH as internal standard was applied and CXC chemokine GRO alpha mRNA in endothelial ECV304 cells was examined. ELISA was used to determine GRO alpha protein expression on ECV304 cells surface and in the medium. With static cell adhesion assays, the physiological significance of elevated GRO alpha expression was tested.

RESULTS

OxLDL, not LDL, treatment of ECV304 cells significantly induced the expression of GRO alpha mRNA that was not detectable in untreated cells. Induction of expression was first evident at 1 h, became maximal at 2 h, and was substantially decreased by 4 h. In a concentration- and time-dependent manner, oxLDL, and not LDL, induced a significant upregulation of GRO alpha surface expression in ECV304 cells that was at a barely detectable level in unstimulated ECV304 cells. GRO alpha protein in the medium did not change significantly. Exposure of ECV304 cells to 40 micrograms protein/ml oxLDL for 24 h resulted in a marked increase in the number of U937 cells bound to ECV304 cells and antibodies to GRO alpha inhibited adhesion.

CONCLUSION

OxLDL functionally upregulated GRO alpha expression in endothelial cells.

[Production of monoclonal antibodies to broad bean wilt virus and application in virus detection]

Six hybridoma cell lines secretion monoclonal antibodies(MAbs) against broad bean wilt virus(BBWV) were produced by fusing mouse myeloma cells(SP 2/0) with spleen cells from BAL B/c immunized by the BBWV particles. The hybridoma cell lines secreted MAbs stably after cultured in vitro for 3 months or stored in liquid nitrogen and then revived for several times. The titres of ascitic fluids of six MAbs ranged from 1:256,000 to 1:640,000 when measured by indirect ELISA. In agarose gel immunodiffusion test, it showed that the six MAbs represented the same isotype of murine antibodies, IgG1. Six MAbs could detect 4 tested BBWV isolates, but didn't crossreact with other 5 plant viruses. The result of Western blot showed that all the six MAbs can react with the 44.7 kD large coat protein subunit of BBWV. This is the first report of production of MAbs against BBWV.

Ultrastructural localization of insulin-like growth factor-2 (IGF-2) to the secretory granules of insulin cells: a study in normal and diabetic (GK) rats

By using biochemical and light-microscopical techniques, insulin-like growth factor-2 (IGF-2) has recently been found in adult pancreas, co-localized immunohistochemically with insulin in the islet B-cells. The purpose of this study was to trace IGF-2 immunoreactivity (IR) at the ultrastructural level in normal and diabetic Goto-Kakizaki (GK) rats. Using a pre-embedding technique and immuno-gold-silver staining, IGF-2 antibody binding was localized exclusively to the halo of a subset of secretory beta-granules in normal rats. Insulin IR occurred more frequently in the granules. GK rats had, in addition to normal-looking islets, some islets with irregular shape and an increased amount of fibrous tissue, so-called "starfish-shaped" islets. In these, beta-granules were usually found, but most of the B-cells were also occupied by large, usually electron-translucent vesicles, some resembling crinophagic bodies, i.e., the sign of intracellular degradation of secretory granules. In starfish-shaped islets, IGF-2 IR was localized to the halo of beta-granules, as in GK islets with normal appearance. Occasionally, IGF-2 IR was also found in the cytoplasm and even in adjacent fibroblasts. Insulin IR was restricted to beta-granules. Because the lysosomes have IGF-2 receptors, the presence of IGF-2 peptide in secretory granules could explain why some granules are guided to lysosomes for degradation.

Generalized immune activation in pulmonary tuberculosis: co-activation with HIV infection

Parameters of immune activation/differentiation were studied in a group of newly diagnosed HIV- and HIV+ pulmonary tuberculosis (TB) patients. Compared with controls, HLA-DR expression on both CD4 and CD8 T cells from the HIV- TB patients was approximately doubled; HLA-DR on T cells from the HIV+ group was tripled. The monocytes from both groups of patients expressed abnormally high levels of the Fc gamma receptors I and III. Serum levels of tumour necrosis factor-alpha (TNF-alpha), neopterin and beta 2-microglobulin were increased in HIV- and even more so in HIV+ TB patients. The expression of HLA-DR on T cell subsets and of Fc gamma R on monocytes correlated with each other, but not with serum activation markers. This pattern of non-specific activation during TB infection may be associated with enhanced susceptibility to HIV infection.

Primary isolates of human immunodeficiency virus type 1 are relatively resistant to neutralization by monoclonal antibodies to gp120, and their neutralization is not predicted by studies with monomeric gp120

A panel of anti-gp120 human monoclonal antibodies (HuMAbs), CD4-IgG, and sera from people infected with human immunodeficiency virus type 1 (HIV-1) was tested for neutralization of nine primary HIV-1 isolates, one molecularly cloned primary strain (JR-CSF), and two strains (IIIB and MN) adapted for growth in transformed T-cell lines. All the viruses were grown in mitogen-stimulated peripheral blood mononuclear cells and were tested for their ability to infect these cells in the presence and absence of the reagents mentioned above. In general, the primary isolates were relatively resistant to neutralization by the MAbs tested, compared with the T-cell line-adapted strains. However, one HuMAb, IgG1b12, was able to neutralize most of the primary isolates at concentrations of < or = 1 microgram/ml. Usually, the inability of a HuMAb to neutralize a primary isolate was not due merely to the absence of the antibody epitope from the virus; the majority of the HuMAbs bound with high affinity to monomeric gp120 molecules derived from various strains but neutralized the viruses inefficiently. We infer therefore that the mechanism of resistance of primary isolates to most neutralizing antibodies is complex, and we suggest that it involves an inaccessibility of antibody binding sites in the context of the native glycoprotein complex on the virion. Such a mechanism would parallel that which was previously postulated for soluble CD4 resistance. We conclude that studies of HIV-1 neutralization that rely on strains adapted to growth in transformed T-cell lines yield the misleading impression that HIV-1 is readily neutralized. The more relevant primary HIV-1 isolates are relatively resistant to neutralization, although these isolates can be potently neutralized by a subset of human polyclonal or monoclonal antibodies.

Restriction fragment length polymorphisms of Anisakinae larvae

The analysis of restriction fragment length polymorphisms (RFLPs) was applied to distinguish several kinds of Anisakinae larvae, Anisakis larvae (type I) collected from two different paratenic hosts, Anisakis larvae (type II) and Contracaecum larvae. The patterns of the two different paratenic host-derived DNA of Anisakis larva (I) were exactly the same in hybridized fragments generated by six endonucleases. The quite different patterns in RFLPs of genomic DNA were observed among the Anisakis larva (I), Anisakis larva (II) and Contracaecum larvae. The results suggest that the RFLPs analysis may be useful for distinguishing Anisakinae larvae and clarifying the relationships between Anisakis larvae and their adult worms.