Prickly Pear Betalain-Rich Extracts as New Promising Strategy for Intestinal Inflammation: Plant Complex vs. Main Isolated Bioactive Compounds

Recently, many studies have highlighted the health effects of betalains beyond their use as food dyes. The present study investigated betalain-rich extracts with different colors and their main bioactive compounds in order to provide first evidence as a new promising strategy for intestinal inflammation management. Prickly pear betalain–rich extracts, obtained by a QuEChERS method, have been characterized by LC-DAD-ESI-MS/MS analysis. The potential role of betanin, indicaxanthin, and prickly pear extracts in counteracting the antioxidant and anti-inflammatory events was evaluated by several in vitro cell-free and cell-based assays. Indicaxanthin and betanin represent the most abundant compounds (≥22.27 ± 4.50 and 1.16 ± 0.17 g/100 g dry extract, respectively). Prickly pear extracts showed the strongest antioxidant and anti-inflammatory activities with respect to the pure betalains both on in vitro cell-free and cell-based assays, demonstrating the occurrence of synergistic activity, without any cytotoxicity or alteration of the barrier systems. The release of reactive oxygen species (ROS) and key inflammatory markers (IL-6, IL-8, and NO) was strongly inhibited by both betalains and even more by prickly pear extracts, which showed a similar and sometimes better profile than the reference compounds trolox and dexamethasone in counteracting the IL-1β–induced intestinal inflammation.

Gene expression profile in metastatic and non-metastatic parathyroid carcinoma

Parathyroid carcinoma (PC) is one of the rarest and aggressive malignancies of the endocrine system. In some instances, the histological diagnosis remains uncertain unless there is evidence of gross local invasion or secondary spread. The identification of molecular markers could improve the diagnostic accuracy of these lesions. The expression of 740 genes involved in the tumor progression processes was assessed in 8 parathyroid adenomas (PAs), 17 non-metastatic and 10 metastatic PCs using NanoString technology. Clustering analysis and Ingenuity Pathway Analysis (IPA) were interrogated to compare the gene expression profiles among the three analyzed groups and to evaluate the potential role of differentially expressed genes, respectively. The 103 differentially expressed genes between metastatic PCs and PAs are able to discriminate perfectly the two groups from a molecular point of view. The molecular signatures identified in non-metastatic PCs vs PAs and in metastatic PCs vs non-metastatic PCs comparisons, although with some exceptions, seem to be histotype-specific IPA reveals that hepatic fibrosis/hepatic stellate cell activation and GP6 signaling pathway are involved in malignant behavior of parathyroid tumors, whereas the activation of the HOTAIR regulatory pathway are involved in the metastatization process. Our investigation identified differentially expressed genes in non-metastatic PCs mainly encoding ECM proteins and in metastatic PCs driving endothelial-to-mesenchymal transition or encoding mediators of angiogenesis. The identified genes might be promising molecular markers potentially useful in the clinical practice for the early diagnosis and prognosis of PC.

Immune Transcriptome of Cells Infected with Enterovirus Strains Obtained from Cases of Type 1 Diabetes

Enterovirus (EV) infection of insulin-producing pancreatic beta cells is associated with type 1 diabetes (T1D), but little is known about the mechanisms that lead the virus to cause a persistent infection and, possibly, to induce beta cell autoimmunity. A cell line susceptible to most enterovirus types was infected with EV isolates from cases of T1D and, for comparison, with a replication-competent strain of coxsackievirus B3. The transcription of immune-related genes and secretion of cytokines was evaluated in infected vs. uninfected cells. Acutely infected cells showed the preserved transcription of type I interferon (IFN) pathways and the enhanced transcription/secretion of IL6, IL8, LIF, MCP1, and TGFB1. On the other hand, infection by defective EV strains obtained from diabetic subjects suppressed IFN pathways and the transcription of most cytokines, while enhancing the expression of IL8, IL18, IL32, and MCP1. IL18 and IL32 are known for their pathogenic role in autoimmune diabetes. Thus, the cytokine profile of AV3 cells infected by diabetes-derived EV strains closely matches that observed in patients at the early stages of T1D. The concordance of our results with clinically verified information reinforces the hypothesis that the immune changes observed in type 1 diabetic patients are due to a hardly noticeable virus infection.

Myofibroblast Gene Expression Profile after Tooth Extraction in the Rabbit

After tooth extraction, the alveolar bone tends to shrink in volume, especially on the vestibular side. The role of myofibroblasts in bone remodeling has not been sufficiently investigated. The aim of the present study was to explore the gene expression related to myofibroblasts presence and activity during a 90-day healing period after tooth extraction. The study included 36 rabbits, and a single tooth extraction was performed on each rabbit. The extractive sockets were randomly distributed to natural healing or to scarification of the wound. The sacrifices were staggered in such a manner that animals contributed with sockets representing 2, 7, 15, 30, 60, and 90 days of healing. Nanostring technology was used to evaluate the expression of a wide panel consisting in 148 genes related to the activation, induction, and suppression of myofibroblasts, socket microenvironment, and autophagy. We found that the expression profile of this custom panel was time-related. The post-extractive socket was subjected to significant gene expression changes after 15 days: the genes involved in the induction of myofibroblasts were up-regulated in the first 15-day period and down-regulated during the rest of the follow-up. The study suggested that myofibroblasts play a major role in the immediate 15-day period following tooth extraction.

Junctional adhesion molecule-A is down-regulated in anaplastic thyroid carcinomas and reduces cancer cell aggressiveness by modulating p53 and GSK3 α/β pathways

Junctional adhesion molecule A (JAM-A) is a transmembrane protein that contributes to different biological process, including the epithelial to mesenchymal transition (EMT). Through an EMT profiler array, we explored the molecular players associated with human thyroid cancer progression and identified JAM-A as one of the genes mostly deregulated. The quantitative real-time polymerase chain reaction and immunohistochemistry analyses showed that downregulation of JAM-A occurred in anaplastic thyroid carcinoma (ATC) compared with normal thyroid (NT) and papillary thyroid carcinoma (PTC) tissues and correlated with extrathyroid infiltration, tumor size, and ATC histotype. In ATC cell lines, JAM-A restoration suppressed malignant hallmarks of transformation including cell proliferation, motility, and transendothelial migration. Accordingly, knockdown of JAM-A enhanced thyroid cancer cell proliferation and motility in PTC cells. Through the proteome profiler human phospho-kinase array, we demonstrated that higher expression of JAM-A was associated with a significant increased level of phosphorylation of p53 and GSK3 α/β proteins. In conclusion, our findings highlight a novel role of JAM-A in thyroid cancer progression and suggest that JAM-A restoration could have potential clinical relevance in thyroid cancer treatment.

mRNA and miRNA expression profiling of follicular variant of papillary thyroid carcinoma with and without distant metastases

Follicular Variant of Papillary Thyroid Carcinoma (FVPTC) is usually associated with a good outcome. Nevertheless, in rare cases, it develops distant metastases (1-9%). Our goal was to investigate whether mRNA and miRNA expression profiles may help distinguish between metastatic versus non-metastatic FVPTCs. Twenty-four primary FVPTCs, 12 metastatic and 12 non-metastatic, with similar clinicopathological features were selected and analyzed by nanoString nCounter technology using two distinct panels for expression analysis of 740 mRNA and 798 miRNAs. Data analysis was performed using the nanoString nSolver 3.0 software. Forty-seven mRNA and 35 miRNAs were differentially expressed between the two groups. Using these mRNA and miRNAs, metastatic and non-metastatic FVPTCs were clearly divided into two distinct clusters. Our results indicate that FVPTCs with metastatic abilities have different expression profiles compared to the non-metastatic. A prospective validation is needed to evaluate the usefulness of this molecular approach in the early identification of high-risk FVPTCs.

Abstract 5402: A panel of miRNAs for diagnosis of wild-type thyroid nodules with pre-surgical indeterminate cytology

Fine-needle aspiration (FNA) cytology is the gold standard for the evaluation of thyroid nodules, but about 30% are cytologically indeterminate. The inability to resolve preoperative thyroid nodules as benign or malignant is therefore a challenge. Molecular tests in FNA are useful to assist the diagnosis and the management of patients. However, if a thyroid nodule is indeterminate and genetic tests are inconclusive, surgical excision may be considered for definitive diagnosis. To overcome these limitations, novel diagnostic procedures and molecular tests are required. Among these, miRNAs have been reported as promising molecular markers in thyroid cancer.

The aim of this study was to evaluate the potential diagnostic utility of miRNA expression in preoperative diagnosis of thyroid nodules with indeterminate cytology and wild type in RAS family genes and BRAF gene.

The miRNA expression profile was evaluated in a small cohort of 12 wild-type Follicular Adenomas (FAs) and 4 wild-type Infiltrative Follicular Variant of Papillary Thyroid Carcinomas (IFVPTCs) with pre-surgical indeterminate cytology or in patients with cytological diagnosis not available. The two groups have been selected with similar characteristics in terms of age of patients, nodules size and with a ratio Male-Female 1:3. The expression of 798 miRNAs has been evaluated by using nCounter Nanostring technology, a sensitive and reproducible method. The differential miRNAs expression between FAs and IFVPTCs was investigated by applying the non-parametric Mann-Whitney U-test. In addition, an unsupervised hierarchical clustering analysis by Pearson correlation was performed.

We found a set of 13 miRNAs differentially expressed between malignant and benign lesions. miR-222-3p, miR-30d-5p, miR-100-5p, miR-1972, miR-125b-5p, miR-155-5p were significantly up-regulated, whereas miR-574-5p, let-7f-5p, miR-148a-3p, miR-598-3p, miR-195-5p, miR-301a-3p, miR-5196-3p+hsa-miR-6732-3p were significantly down-regulated in IFVPTCs compared to FAs (p-value<0,05). The unsupervised hierarchical clustering analysis has identified 2 main clusters: the first one consisted of 9 FAs, whereas the second one consisted of 4 IFVPTCs and 3 FAs. The 4 IFVPTCs are grouped in an unique sub-cluster with a correlation of 0,74. This miRNA expression profile could distinguish malignant from benign lesions. If these results will be confirmed in a wide cohort of patients and in FNA cytology, this strategy could increase the diagnostic yield and improve the preoperative diagnosis of wild-type thyroid nodules with indeterminate cytology.

Although this is a preliminary study, the deregulation of this set of miRNAs might help identify malignant nodules that are negative for well-known gene alterations in preoperative FNAs.

Citation Format: Maria Denaro, Vincenzo Condello, Clara Ugolini, Elisabetta Macerola, Anello Marcello Poma, Gabriele Materazzi, Paolo Vitti, Fulvio Basolo. A panel of miRNAs for diagnosis of wild-type thyroid nodules with pre-surgical indeterminate cytology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5402.

The problem of misidentification between edible and poisonous wild plants: Reports from the Mediterranean area

Today, in many European countries, people are looking for wild edible plants to experience new tastes and flavors, by following the new trend of being green and environmentally friendly. Young borage and spinach leaves can be easily confused by inexpert pickers with those of other plants, including poisonous ones, such as Mandragora autumnalis Bertol. (mandrake) or Digitalis purpurea L. (foxglove), common in southern and northern Italy respectively. In the last twenty years, several cases of intoxication by accidental ingestion of mandrake and foxglove have been reported. The purpose of this work was to perform a pharmacognostic characterization of young leaves from borage, mandrake, foxglove and spinach, by micro-morphological, molecular and phytochemical techniques. The results showed that each of the three techniques investigated could be sufficient alone to provide useful information for the identification of poisonous species helping the medical staff to manage quickly the poisoned patients. However, the multi-disciplinary approach proposed could be very useful to asses the presence of poisonous plants in complex matrices, to build a database containing morphological, molecular and phytochemical data for the identification of poisonous species or in forensic toxicology, given their increasingly frequent use due to their low cost and relatively common availability.

Ex Vivo Selection of Transduced Hematopoietic Stem Cells for Gene Therapy of β-Hemoglobinopathies

Although gene transfer to hematopoietic stem cells (HSCs) has shown therapeutic efficacy in recent trials for several individuals with inherited disorders, transduction incompleteness of the HSC population remains a hurdle to yield a cure for all patients with reasonably low integrated vector numbers. In previous attempts at HSC selection, massive loss of transduced HSCs, contamination with non-transduced cells, or lack of applicability to large cell populations has rendered the procedures out of reach for human applications. Here, we fused codon-optimized puromycin N-acetyltransferase to herpes simplex virus thymidine kinase. When expressed from a ubiquitous promoter within a complex lentiviral vector comprising the βAT87Q-globin gene, viral titers and therapeutic gene expression were maintained at effective levels. Complete selection and preservation of transduced HSCs were achieved after brief exposure to puromycin in the presence of MDR1 blocking agents, suggesting the procedure's suitability for human clinical applications while affording the additional safety of conditional suicide.

Polyphenolic profile and biological activities of black carrot crude extract (Daucus carota L. ssp. sativus var. atrorubens Alef.)

Black carrot (Daucus carota L. ssp. sativus var. atrorubens Alef.) is a valuable source of carbohydrates, minerals and vitamins and contains also high amounts of anthocyanins giving the characteristic deep-purple color. These latter compounds are known as natural dyes used in the food and pharmaceutical industry that have recently attracted much attention for their healthful properties. The aim of this work was to investigate for the first time the polyphenolic profile and biological properties of a black carrot crude extract (BCCE) through an in-depth analysis of the main polyphenolic classes evaluating its antioxidant, cytoprotective and anti-angiogenic properties. Twenty five polyphenols were quantified by LC-DAD-FLD-MS/MS analysis (anthocyanins 78.06%, phenolic acids 17.89% and other flavonoids 4.06%) with polyglycosylated cyanidins as major components. In addition, BCCE showed a strong antioxidant and free radical scavenging activity particularly in the hydrogen transfer-based assays (ORAC and β-carotene bleaching) and a significant increase in the cell viability. Furthermore, BCCE exhibited a strong anti-angiogenic activity at the highest concentration assayed on the chick chorioallantoic membrane (50μg/egg). In conclusion, the obtained results demonstrated the antioxidant, cytoprotective and anti-angiogenic properties of BCCE, which highlight that the higher biological activity of BCCE is probably due to the synergic effects exerted by various polyphenolic classes.

Differences in miRNA expression profiles between wild-type and mutated NIFTPs

Noninvasive encapsulated follicular variants of papillary thyroid carcinomas have been recently reclassified as noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTPs). NIFTPs exhibit a behavior that is very close to that of follicular adenomas but different from the infiltrative and invasive follicular variants of papillary thyroid carcinomas (FVPTCs). The importance of miRNAs to carcinogenesis has been reported in recent years. miRNAs seem to be promising diagnostic and prognostic molecular markers for thyroid cancer, and the combination of miRNA expression and mutational status might improve cytological diagnosis. The aim of the present study was to evaluate the miRNA expression profile in wild-type, RAS- or BRAF-mutated NIFTPs, infiltrative and invasive FVPTCs, and follicular adenomas using the nCounter miRNA Expression assay (NanoString Technologies). To identify the significant Kyoto Encyclopedia of Genes and Genomes (KEGG) molecular pathways associated with deregulated miRNAs, we used the union of pathways option in DNA Intelligent Analysis (DIANA) miRPath software. We have shown that the miRNA expression profiles of wild-type and mutated NIFTPs could be different. The expression profile of wild-type NIFTPs seems comparable to that of follicular adenomas, whereas mutated NIFTPs have an expression profile similar to that of infiltrative and invasive FVPTCs. The upregulation of 4 miRNAs (miR-221-5p, miR-221-3p, miR-222-3p, miR-146b-5p) and the downregulation of 8 miRNAs (miR-181a-3p, miR-28-5p, miR-363-3p, miR-342-3p, miR-1285-5p, miR-152-3p, miR-25-3p, miR-30e-3) in mutated NIFTPs compared to wild-type ones suggest a potential invasive-like phenotype by deregulating the specific pathways involved in cell adhesion and cell migration (Hippo signaling pathway, ECM-receptor interaction, adherens junction, regulation of actin cytoskeleton, fatty acid biosynthesis and metabolism).

MET exon 14 mutations in advanced lung adenocarcinoma: Frequency and coexisting alterations

e20656

Background: In lung cancer the evaluation of MET, a tyrosine kinase receptor involved in tumor growth and invasiveness, for copy number amplification and point mutations is relevant for prognosis and therapy. In lung adenocarcinoma (ADC) MET amplification is observed in 1-2% and MET mutations in 3-4% of cases. Mutations mainly occur in exon 14 (ex14), which encodes for the juxtamembrane negative regulatory domain, including splice site alterations and missense mutations within the exon.Commonly, MET ex14 alterations, in particular splice site ones, are mutually exclusive with other driver mutations, but co-occurrence with MET and MDM2 amplification and KRAS mutations was described. We evaluated METex14 mutation frequency and coexistence with additional driver alterations in a prospective cohort of Italian ADC patients. Methods: 315 ADC patients were tested (January-December 2016) for MET ex14 alterations by Sanger Sequencing on formalin-fixed paraffin-embedded tissues and cytological smears (tumor cells > 40%). MET positive cases were screened also for other oncogenes, among which KRAS, BRAF and PIK3CA, using a MALDI-TOF platform, and for ROS1 translocations and MET amplification by FISH. Results: 16 patients (5%) were MET positive: 7 splice site mutations (43%) and 9 (57%) other alterations within ex14. Among splice site mutations 1 co-occurred with ROS1 translocation and 1 with MET amplification. Among other mutations we found 5 T1010I missense mutations: 3 co-occurring with G12D/G13C/Q61H KRAS, 1 with G469A BRAF and 1 with a MET intron 13 point mutation; 2 R988C mutations: 1 with G13C KRAS and 1 with G13C KRAS plus ROS1 translocation; 1 P1026S mutation and 1 frameshift deletion (p.A991del;R992fs*999), both with G12C KRAS. Conclusions: Splice site mutations cause MET activation by exon skipping and increase sensitivity to tyrosine-kinase inhibitors, whereas how other ex14 mutations affect MET function is not fully understood. In our cohort we found a high rate of METex14 mutations together with alterations in other oncogenes, mostly KRAS. The interaction of MET with cancer signaling pathways deserve further investigation in order to better define the role of ex14 mutations in the context of target therapy.

Preclinical evaluation of efficacy and safety of an improved lentiviral vector for the treatment of β-thalassemia and sickle cell disease

A previously published clinical trial demonstrated the benefit of autologous CD34(+) cells transduced with a selfinactivating lentiviral vector (HPV569) containing an engineered β-globin gene (β(A-T87Q)-globin) in a subject with β thalassemia major. This vector has been modified to increase transduction efficacy without compromising safety. In vitro analyses indicated that the changes resulted in both increased vector titers (3 to 4 fold) and increased transduction efficacy (2 to 3 fold). An in vivo study in which 58 β-thalassemic mice were transplanted with vector- or mock-transduced syngenic bone marrow cells indicated sustained therapeutic efficacy. Secondary transplantations involving 108 recipients were performed to evaluate long-term safety. The six month study showed no hematological or biochemical toxicity. Integration site (IS) profile revealed an oligo/polyclonal hematopoietic reconstitution in the primary transplants and reduced clonality in secondary transplants. Tumor cells were detected in the secondary transplant mice in all treatment groups (including the control group), without statistical differences in the tumor incidence. Immunohistochemistry and quantitative PCR demonstrated that tumor cells were not derived from transduced donor cells. This comprehensive efficacy and safety data provided the basis for initiating two clinical trials with this second generation vector (BB305) in Europe and in the USA in patients with β-thalassemia major and sickle cell disease.

Association of the DNMT3B -579G>T polymorphism with risk of thymomas in patients with myasthenia gravis

Increasing evidence suggests a contribution of epigenetic processes in promoting cancer and autoimmunity. Myasthenia gravis (MG) is an autoimmune disease mediated, in approximately 80% of the patients, by antibodies against the nicotinic acetylcholine receptor (AChR+). Moreover, epithelial tumours (thymomas) are present in about 10-20% of the patients, and there is indication that changes in DNA methylation might contribute to the risk and progression of thymomas. However, the role of epigenetics in MG is still not completely clarified. In the present study we investigated if a common polymorphism (-579G>T: rs1569686) in the promoter of the DNMT3B gene coding for the DNA methyltransferase 3B, an enzyme that mediates DNA methylation, increases the risk to develop MG or MG-associated thymomas. The study polymorphism was selected based on recent reports and a literature meta-analysis suggesting association with increased risk of various types of cancer. We screened 324 AChR+ MG patients (140 males and 184 females, mean age 56.0 ± 16.5 years) and 735 healthy matched controls (294 males and 441 females, mean age 57.3 ± 15.6 years). 94 of the total MG patients had a thymoma. While there was no association with the whole cohort of MG patients, we found a statistically significant association of the DNMT3B-579T allele (OR = 1.51; 95% CI=1.1-2.1, P = 0.01) and the TT homozygous genotype (OR = 2.59; 95% CI=1.4-4.9, P = 0.006) with the risk of thymoma. No association was observed in MG patients without thymoma, even after stratification into clinical subtypes. Present results suggest that the DNMT3B-579T allele might contribute to the risk of developing thymoma in MG patients, particularly in homozygous TT subjects.

Transfusion independence and HMGA2 activation after gene therapy of human β-thalassaemia

The β-haemoglobinopathies are the most prevalent inherited disorders worldwide. Gene therapy of β-thalassaemia is particularly challenging given the requirement for massive haemoglobin production in a lineage-specific manner and the lack of selective advantage for corrected haematopoietic stem cells. Compound β(E)/β(0)-thalassaemia is the most common form of severe thalassaemia in southeast Asian countries and their diasporas. The β(E)-globin allele bears a point mutation that causes alternative splicing. The abnormally spliced form is non-coding, whereas the correctly spliced messenger RNA expresses a mutated β(E)-globin with partial instability. When this is compounded with a non-functional β(0) allele, a profound decrease in β-globin synthesis results, and approximately half of β(E)/β(0)-thalassaemia patients are transfusion-dependent. The only available curative therapy is allogeneic haematopoietic stem cell transplantation, although most patients do not have a human-leukocyte-antigen-matched, geno-identical donor, and those who do still risk rejection or graft-versus-host disease. Here we show that, 33 months after lentiviral β-globin gene transfer, an adult patient with severe β(E)/β(0)-thalassaemia dependent on monthly transfusions since early childhood has become transfusion independent for the past 21 months. Blood haemoglobin is maintained between 9 and 10 g dl(-1), of which one-third contains vector-encoded β-globin. Most of the therapeutic benefit results from a dominant, myeloid-biased cell clone, in which the integrated vector causes transcriptional activation of HMGA2 in erythroid cells with further increased expression of a truncated HMGA2 mRNA insensitive to degradation by let-7 microRNAs. The clonal dominance that accompanies therapeutic efficacy may be coincidental and stochastic or result from a hitherto benign cell expansion caused by dysregulation of the HMGA2 gene in stem/progenitor cells.

Idebenone in senile dementia of Alzheimer type: a multicentre study

Idebenone is a new cerebro-active drug, effective in dementia disorders, particularly indicated in primary degenerative dementias, i.e. Alzheimer's disease. This new molecule acts as an electron trapper and a free radical scavenger protecting mitochondrial membranes from lipid peroxidation. A multicentric, double-blind trial of idebenone (45 mg twice daily orally) vs. placebo was carried out on 102 elderly patients affected by Alzheimer-type dementia of mild or moderate severity. Idebenone was administered for 4 consecutive months, 45 mg twice daily. Clinical evaluations were performed at the time of enrollment (t0) and monthly thereafter (t30, t60, t90 and t120) and at follow-up (t150 ). Tolerability to idebenone treatment was good and was associated with a statistically significant improvement of memory, attention and behaviour. It is worthwhile noting that these cognitive and behavioral findings were observed after the first month of treatment with enhancement evident in the following period.

Bone marrow transplantation from alpha1,3-galactosyltransferase gene-knockout pigs in baboons

BACKGROUND

Successful hematopoietic cell allotransplantation results in donor-specific tolerance, but this approach has been unsuccessful in the wild-type pig-to-baboon xenotransplantation model, as pig cells were lost from the circulation within 5 days. However, after cessation of immunosuppressive therapy on day 28, all baboons demonstrated non-specific unresponsiveness on mixed leukocyte reaction (MLR) for at least 30 days. We have now investigated the transplantation of bone marrow (BM) cells from miniature swine homozygous for alpha1,3-galactosyltransferase gene-knockout (GalT-KO).

METHODS

Baboons (n = 3) were pre-treated with whole body and thymic irradiation, anti-thymocyte globulin, and splenectomy, and received immunosuppressive and supportive therapy for 28 days. BM was harvested from GalT-KO swine (n = 3). The baboons were monitored for the presence of pig cells by flow cytometry and colony-forming units (CFUs), and for cellular reactivity by MLR.

RESULTS

A mean of 11 x 10(8) BM cells/kg was infused into each baboon. The mean absolute numbers and percentages of pig cells detected in the blood at 2 h and on days 1, 2 and 4, respectively, were 641/microl (9.5%), 132/microl (3.4%), 242/microl (3.9%), and 156/microl (2.9%). One baboon died (from accidental hemorrhage) on day 6, at which time chimerism was present in the blood (2.0%) and BM (6.4%); pig cell engraftment in the BM was confirmed by polymerase chain reaction (PCR) of CFUs. In the two other baboons, blood chimerism was lost after day 5 but returned at low levels (<1%) between days 9 to 16 and 7 to 17, respectively, indicating transient BM engraftment. Both surviving baboons showed non-specific unresponsiveness on MLR until they were euthanized on days 85 and 110, respectively.

CONCLUSIONS

By using BM cells from GalT-KO pigs, chimerism was detected at levels comparable with previous studies when 30-fold more growth factor-mobilized peripheral blood progenitor cells had been transplanted. In addition, cellular hyporesponsiveness was prolonged. However, long-term engraftment and chimerism were not achieved.

Production of alpha-1,3-galactosyltransferase null pigs by means of nuclear transfer with fibroblasts bearing loss of heterozygosity mutations

Hyperacute rejection of porcine organs by old world primate recipients is mediated through preformed antibodies against galactosyl-alpha-1,3-galactose (Galalpha-1,3-Gal) epitopes expressed on the pig cell surface. Previously, we generated inbred miniature swine with a null allele of the alpha-1,3-galactosyltransferase locus (GGTA1) by nuclear transfer (NT) with gene-targeted fibroblasts. To expedite the generation of GGTA1 null pigs, we selected spontaneous null mutant cells from fibroblast cultures of heterozygous animals for use in another round of NT. An unexpectedly high rate of spontaneous loss of GGTA1 function was observed, with the vast majority of null cells resulting from loss of the WT allele. Healthy piglets, hemizygous and homozygous for the gene-targeted allele, were produced by NT by using fibroblasts that had undergone deletional and crossover/gene conversion events, respectively. Aside from loss of Galalpha-1,3-Gal epitopes, there were no obvious phenotypic differences between these null piglets and WT piglets from the same inbred lines. In fact, congenital abnormalities observed in the heterozygous NT animals did not reappear in the serially produced null animals.

Engraftment of retroviral EGFP-transduced bone marrow in mice prevents rejection of EGFP-transgenic skin grafts

We have investigated whether a state of tolerance toward EGFP-expressing skin tissue can be induced by prior establishment of EGFP molecular chimerism by transplant of gene-transduced bone marrow in mice. Irradiated (10 Gy) C57BL/6J mice were transplanted with bone marrow cells transduced with two different retroviral vectors encoding EGFP. EGFP-transduced, mock-transduced, and age-matched control mice received skin grafts from both C57BL/6 EGFP-transgenic (B6-EGFP. Tg) and MHC-mismatched B10.A donor mice at 8, 29, or 39 weeks after bone marrow transplantation. Although 14 of 17 control mice rejected EGFP.Tg skin grafts within 100 days, 24 of 25 mice receiving EGFP-expressing bone marrow cells accepted their B6-EGFP.Tg grafts out to 200 days after skin grafting, including animals with undetectable levels of EGFP expression in blood cells. The EGFP-transduced animals rejected third-party grafts from MHC-mismatched mice within 20 days, indicating that acceptance of the EGFP-expressing skin grafts was the result of the induction of specific and operational immune tolerance. Thus, our data indicate that (a) EGFP-expressing tissue elicits an immunological rejection in C57BL/6 mice and (b) tolerance can be induced by engrafting relatively small numbers of EGFP-transduced hematopoietic cells. These experiments utilizing EGFP as an immunogen point to the wider therapeutic potential of employing transplantation of gene-transduced hematopoietic cells for establishing immunological tolerance and thereby preventing rejection of gene-corrected cells and tissues.

Expression of xenogeneic MHC class II molecules in HLA-DR(+) and -DR(-) cells: influence of retrovirus vector design and cellular context

We recently established that molecular chimeras of major histocompatibility complex (MHC) class II molecules, created via retroviral transfer of allogeneic class II cDNAs into bone marrow cells (BMCs), alleviated complications associated with mixed BMC chimeras while leading to T cell tolerance to renal grafts sharing the transferred class II. Initially demonstrated for allogeneic transplants in miniature swine, this concept was extended to T-dependent antibody (Ab) responses to xenogeneic antigens (Ags) in the pig --> baboon combination. Successful down-regulation of T cell responses appeared, however, to be contingent on a tight lineage-specific expression of transferred class II molecules. The present studies were, therefore, designed to evaluate the influence of construct design and cellular environment on expression of retrovirally transferred xenogeneic class II cDNAs. Proviral genomes for pig class II SLA-DR expression, differing only at the marker neo(r) or enhanced green fluorescent protein (EGFP) gene, showed increased membrane SLA-DR density on HLA-DR(-) fibroblasts as well as HLA-DR(+), TF-1 erythroleukemia cells. More importantly, HLA-DR(+) human B cell lines, although efficiently transduced with pig DR retroviruses, exhibited unstable surface pig DR. Surface pig DR- B cells, nevertheless, stimulated autologous human T cells pre-sensitized to pig Ags, a proliferation likely occurring through presentation of class II-derived peptides. Collectively, these data suggest that surface expression of transferred class II molecules is not related to the ability of recipient cells to synthesize xenogeneic class II molecules but rather to their Ag processing capacities.

Estimation of lead intake from crystalware under conditions of consumer use

The purpose of this study was to estimate the lead intake from crystalware resulting from short-term contacts with beverages, under conditions that are likely to occur to a consumer. The extraction ability of different kinds of beverages was estimated by comparison with 4% acetic acid under conditions of continuous contact for 3 h. It was found that lead release increased in the following order: cola drink > HAc > whisky > white wine. Under conditions of repeated use under different scenarios, lead release showed a steep decrease with increasing number of contacts, for both wine and cola drink. The maximum lead intake resulted from the cola drink, corresponding to an ingestion of 14.5 micrograms Pb for consumption of 350 ml beverage. Assuming a fixed contribution from the diet of 71 micrograms/day, in the six scenarios taken into consideration, total daily lead intake levels ranged from a minimum of about 76 micrograms up to a maximum of 86 micrograms lead. As these values, converted on a weekly basis, would correspond to 35% and 40% PTWI respectively, significant health risks resulting from the ingestion of beverages in contact with crystalware can be excluded. Finally it was found that the use of a dishwater did not affect significantly the release of lead into wine, while release into cola drink was slightly but significantly increased after the third cycle.

Glucose-lowering and insulin-sensitizing actions of exendin-4: studies in obese diabetic (ob/ob, db/db) mice, diabetic fatty Zucker rats, and diabetic rhesus monkeys (Macaca mulatta)

Exendin-4 is a 39 amino acid peptide isolated from the salivary secretions of the Gila monster (Heloderma suspectum). It shows 53% sequence similarity to glucagon-like peptide (GLP)-1. Unlike GLP-1, exendin-4 has a prolonged glucose-lowering action in vivo. We compared the potency and duration of glucose-lowering effects of exendin-4 and GLP-1 in hyperglycemic db/db and ob/ob mice. Whereas reductions in plasma glucose of up to 35% vanished within 1 h with most doses of GLP-1, the same doses of exendin-4 resulted in a similar glucose-lowering effect that persisted for >4 h. Exendin-4 was 5,530-fold more potent than GLP-1 in db/db mice (effective doses, 50% [ED50s] of 0.059 microg/kg +/-0.15 log and 329 microg/kg+/-0.22 log, respectively) and was 5,480-fold more potent in ob/ob mice (ED50s of 0.136 microg/kg+/-0.10 log and 744 microg/kg+/-0.21 log, respectively) when the percentage fall in plasma glucose at 1 h was used as the indicator response. Exendin-4 dose-dependently accelerated glucose lowering in diabetic rhesus monkeys by up to 37% with an ED50 of 0.25 microg/kg +/-0.09 log. In two experiments in which diabetic fatty Zucker rats were injected subcutaneously twice daily for 5-6 weeks with doses of exendin-4 up to 100 microg x rat(-1) x day(-1) (approximately 250 microg/kg), HbA1c was reduced relative to saline-injected control rats. Exendin-4 treatment was also associated in each of these experiments with weight loss and improved insulin sensitivity, as demonstrated by increases of up to 32 and 49%, respectively, in the glucose infusion rate (GIR) in the hyperinsulinemic euglycemic clamp. ED50s for weight loss and the increase in clamp GIR were 1.0 microg/kg+/-0.15 log and 2.4 microg/kg+/-0.41 log, respectively. In conclusion, acute and chronic administration of exendin-4 has demonstrated an antidiabetic effect in several animal models of type 2 diabetes.

Roles of amylin in diabetes and in regulation of nutrient load

In summary, amylin, via its hormonal actions, may be relevant to the treatment of both forms of diabetes, and, paradoxically, via its amyloidogenic properties, may also be relevant to the pathogenesis of NIDDM. Amylin potently inhibits postprandial glucagon secretion. The absence of this action could contribute to the hyperglucagonemia and subsequently, excessive endogenous glucose production, fasting hyperglycemia, and propensity to ketosis seen in insulinopenic diabetes. Restoration of normal glucagon secretion by amylin replacement therapy could therefore be therapeutically important in treatment of insulin-dependent diabetes mellitus. Amylin potently inhibits gastric emptying. This action is consistent with a physiologic role of amylin to regulate carbohydrate absorption. Of peptides known to be secreted in response to ingested carbohydrate, only amylin and glucagon-like peptide-1 are reported to inhibit gastric emptying at near-physiologic concentrations, and could therefore participate in nutrient-mediated feedback control of carbohydrate release from the stomach. Amylin reduces food intake in rodents. This action, which synergizes with a similar action of CCK, could reflect a role as short-term peripheral satiety agent. Amylin alone or in combination with CCK may be useful in moderating caloric intake in obesity and other metabolic disorders. Although insulin has been extensively studied as a therapy and as a controller of nutrient storage and metabolism, the role of its beta-cell partner, amylin, has been largely unrecognized. In contrast to the nutrient disposal and storage role of insulin, amylin appears to more generally address the opposite side of the energy balance equation, the assimilation of nutrient.

Identification of a full-length cDNA for an endogenous retrovirus of miniature swine

Endogenous retroviruses of swine are a concern in the use of pig-derived tissues for xenotransplantation into humans. The nucleotide sequence of porcine endogenous retrovirus taken from lymphocytes of miniature swine (PERV-MSL) has been characterized. PERV-MSL is a type C retrovirus of 8,132 bp with the greatest nucleic acid sequence identity to gibbon ape leukemia virus and murine leukemia virus. Constitutive production of PERV-MSL RNA has been detected in normal leukocytes and in multiple organs of swine. The copy numbers of full-length PERV sequences per genome (approximately 8 to 15) vary among swine strains. The open reading frames for gag, pol, and env in PERV-MSL have over 99% amino acid sequence identity to those of Tsukuba-1 retrovirus and are highly homologous to those of endogenous retrovirus of cell line PK15 (PK15-ERV). Most of the differences in the predicted amino acid sequences of PK15-ERV and PERV-MSL are in the SU (cell attachment) region of env. The existence of these PERV clones will enable studies of infection by endogenous retroviruses in xenotransplantation.

Gel permeation chromatography (GPC) of repeatedly extruded polyethylene terephthalate (PET)

The paper deals with gel permeation chromatography (GPC) monitoring of the behaviour of PET (polyethylene terephthalate) after repeated extrusions. Virgin PET was submitted to three successive extrusion/drying cycles and then the samples were swelled with hexafluoroisopropanol and treated with chloroform. GPC analysis was carried out at room temperature on a B.C.S. Serial LC 2000 GPC system equipped with a series of four GPC columns with UV detection at 254 nm and chloroform as eluent. GPC results showed that after each extrusion step the molecular weight distribution of the PET was different and Mw, Mn and Mz decreased. These findings suggest that during each extrusion degradation occurs and that repeated extrusions, as in the case of the recycling PET, may cause an alteration of the molecular weight distribution of the original PET.

Relationships between processing-structure-migration properties for recycled polypropylene in food packaging

In this work the relationships between processing, structure and migration properties of recycled polypropylene (PP) were analysed in relation to the possible use of recycled PP in food packaging applications. PP containers used in food packaging were contaminated with food and then washed, reduced into a processable size, dried and reprocessed by injection moulding. Gel Permeation Chromatography (GPC) analysis, mechanical, and total migration tests were performed on injection moulded samples to verify the effect of the recycling process on the structure and properties of PP. In order to evaluate the effect of the molecular weight on the properties of the recycled polymer, the study was conducted on containers produced by injection moulding made from a low molecular weight (LMW) PP and on containers produced by thermoforming made from a high molecular weight (HMW) PP.

Regulation of the third member of the uncoupling protein family, UCP3, by cold and thyroid hormone

Uncoupling protein (UCP1) is a transmembrane proton transporter present in the mitochondria of brown adipose tissue (BAT), a specialized tissue which functions in temperature homeostasis and energy balance (Nicholls, D. G., and Locke, R. M. (1984) Physiol. Rev. 64, 2-40; Lowell, D. D., and Flier, J. S. (1997) Annu. Rev. Med.). UCP1 mediates the thermogenesis that is characteristic of BAT by uncoupling mitochondrial oxidation of substrates from ATP synthesis. Recently, two proteins related to UCP1 have been identified and designated UCP2 (Fleury, C., et al. (1997) Nature Genetics 15, 269-272) or UCP homolog (UCPH) (Gimeno, R. E., et al. (1997) Diabetes 46, 900-906) and UCP3 (Boss, O., et al. (1997) FEBS Lett. 408, 39-42; Vidal-Puig, A., et al. (1997) Biochem. Biophys. Res. Commun. 235, 79-82). We investigated the regulation in rats of UCP3, which is expressed primarily in skeletal muscle and BAT. Expression of rat UCP3 mRNA in BAT was upregulated by in vivo treatment with triiodothyronine (T3) and by exposure to cold, suggesting that UCP3 is active in thermogenesis and energy expenditure. In skeletal muscle, UCP3 mRNA was also upregulated by T3 but, surprisingly, not by cold exposure. A hypothesis is proposed to account for this differential regulation.

Inhibitors of type-I interleukin-1 receptor from microbial metabolites

We describe here the results of a screening program conducted to discover inhibitors of the type-I interleukin-1 receptor (IL-1RI) from samples of microbial origin. An innovative approach, based on automated, nonradioactive receptor binding assays has been employed. Specially prepared cell-free systems have allowed the use of high concentrations of microbial metabolites in the reaction mixtures with a low percentage of false positives. More than 30,000 microbial samples from different species of soil isolates have been tested and two interesting activities have been purified and characterized. One of these, isolated from Streptomyces sp. GE48009, was identified as niphimycin, an antifungal agent also known as scopafungin. Preliminary evidence suggests that this molecule and azalomycin F, a structural analogue, inhibit IL-IRI by virtue of their long-chain guanidinium moiety. The other activity, isolated from Aspergillus sp. GE49752, was identified as flavipin, a substituted o-phthalaldehyde.

Antimicrobial activities of chemically modified thiazolyl peptide antibiotic MDL 62,879 (GE2270A)

MDL 62,879 (GE2270A) 1 is a new inhibitor of elongation factor-Tu (EF-Tu) and belongs to the class of thiazolyl peptide antibiotics. Controlled acid hydrolysis of 1 followed by treatment with base resulted in the lost of the two terminal amino acids and in the formation of water-soluble MDL 62,935 2. Although less active in vitro than its parent compound, 2 was able to inhibit by 50% an Escherichia coli cell-free protein synthesis system at roughly the same concentration of 1. MDL 62,935 2 was subjected to further modification at the beta-phenylserine residue. Derivatives obtained from 2 were less active in both antimicrobial (MIC) and enzymatic (IC50) assays. This suggests that beta-phenylserine plays an important role for the inhibition of EF-Tu by 1 and 2.

Targeted screening for elongation factor Tu binding antibiotics

The development of a screen targeted to antibiotics which bind elongation factor Tu (EF-Tu) is described. The method was based on selection of antimicrobial activities which were antagonized by exogenous EF-Tu. Kirromycin, a known inhibitor of EF-Tu, was positive in this screen. Among 47,000 microorganisms screened, several producers of kirromycin-type antibiotics were detected and the novel antibiotics GE2270 and GE37468 were discovered. These thiopeptide molecules constitute, along with amithiamycin, a novel class of antibiotics acting on EF-Tu.

A cell-free, nonisotopic, high-throughput assay for inhibitors of type-I interleukin-1 receptor

A cell-free, nonisotopic assay has been developed to discover molecules that compete with the natural ligands for binding to the active site of the Type-I interleukin-1 receptor. The key reagents are the interleukin-1 receptor antagonist, a recombinant soluble form of the receptor (sIL-1R), and a specific anti-sIL-1R nonneutralizing monoclonal antibody (MAb79). With these molecules a sensitive assay has been developed using a reversed format: the ligand is immobilized and the receptor is in solution. The ligand-bound receptor is detected using MAb79 and an enzyme-linked secondary antibody. Since no cells or cell membranes are used, the assay is very robust, with no interference from membrane-perturbing agents and high resistance to the organic solvents normally used to resuspend compounds of chemical libraries. The microplate format and colorimetric detection have allowed the complete automation of the immobilized-ligand IL-1 receptor binding assay, which has been used for high-throughput screening of synthetic compounds and natural products.

In vitro activity of MDL 62,879 against gram-positive bacteria and Bacteroides species

The new thiazolyl peptide antibiotic MDL 62,879 (GE2270 A) showed excellent in vitro activity in testing against staphylococci and streptococci, with MIC90s ranging from 0.23 to 0.9 mg/l. It was very active against Clostridium difficile and Propionibacterium acnes (MIC90 0.06 mg/l in each case) and had variable activity against Bacteroides spp. MDL 62,879 had exceptionally good activity against Enterococcus faecalis, including against a collection of high-level aminoglycoside-resistant isolates where it had an MIC90 of 0.047. The antibiotic was bacteriostatic for enterococcal isolates but bactericidal for a methicillin-resistant isolate of Staphylococcus aureus.

3'-immature tRNA(Trp) is required for ribosome inactivation by gelonin,a plant RNA N-glycosidase

Inactivation of ribosomes by gelonin, a ribosome-inactivating protein with RNA N-glycosidase activity on 28 S rRNA, requires macromolecular cofactors present in post-ribosomal supernatants. One of these cofactors has been purified from a rat liver extract and identified as an RNA about 70 nt long which in sequence analysis shows a high level of similarity with mammalian (bovine) tRNA(Trp). The pattern of the sequencing gel is consistent with the co-existence in the preparation of two 3'-immature tRNA(Trp) species, missing only A75, or both A75 and C74. In the presence of ATP, CTP and tRNA nucleotidyltransferase, the gelonin-stimulating RNA is a good acceptor of tryptophan. An oligodeoxynucleotide complementary to positions 55 to 72 of mammalian (bovine) tRNA(Trp) hybridizes with the gelonin-stimulating RNA as demonstrated by gel mobility shift and ribonuclease H digestion. The oligodeoxynucleotide-directed ribonuclease H treatment also abolishes the gelonin-promoting activity of crude preparations of RNA, giving strong evidence that the only active RNA is a tRNA(Trp)-like molecule.

New semisynthetic glycopeptides MDL 63,246 and MDL 63,042, and other amide derivatives of antibiotic A-40,926 active against highly glycopeptide-resistant VanA enterococci

A series of amide derivatives of natural glycopeptide A-40,926 (A), its 6B-methyl ester (MA) and 6B-decarboxy-6B-hydroxymethyl derivative (RA) were prepared with the aim of obtaining activity against glycopeptide-resistant enterococci. These compounds are structurally related to a class of amides of 34-de(acetylglucosaminyl)-34-deoxy teicoplanin which showed interesting activity against strains of Enterococcus faecalis and E. faecium highly resistant to both vancomycin and teicoplanin. Among them, RA-amides MDL 63,246 and MDL 63,042 were the most active derivatives against several Gram-positive bacteria, including VanB and VanC enterococci, and were moderately active (MIC range 0.5 approximately 64 micrograms/ml) against strains of Enterococcus for which vancomycin and teicoplanin MICs were > or = 128 micrograms/ml. The chemical rationale and the synthesis of these new series of glycopeptide derivatives are described. Preliminary in vitro data are reported and structure-activity relationships are discussed.

Solubilization and identification of essential functional groups of Candida albicans oxidosqualene cyclase

The enzyme properties and location of essential functional groups of solubilized oxidosqualene cyclase of Candida albicans have been studied. We show that the C. albicans enzyme is much more heat-labile compared with Saccharomyces cerevisiae and rat liver cyclases, requires a histidyl residue for enzyme activity, contains an essential thiol residue either close to or in the active site and exhibits a carbocationic mechanism for catalysis, as the enzyme-bound substrate protects the enzyme from inactivation by a site-directed inactivator.

Amides of de-acetylglucosaminyl-deoxy teicoplanin active against highly glycopeptide-resistant enterococci. Synthesis and antibacterial activity

Removal, by selective reduction, of the acetylglucosamine from teicoplanin A2-2 (CTA/2) produced the 34-de(acetylglucosaminyl)-34-deoxy pseudoaglycone (II). This compound was more active in vitro than CTA/2 against coagulase-negative staphylococci (CNS). Amide derivatives obtained by condensation of the carboxyl group of II with primary amines were particularly active against Streptococcus pyogenes and had some in vitro activity against VanA enterococci highly resistant to both teicoplanin and vancomycin. Among them, a carboxamide (VII) with a branched tetramine also had better activity than the corresponding amide of teicoplanin against CNS. In contrast, the dimethylamide (VIII) of II had little activity against VanA enterococci. While the overall structure of the heptapeptide backbone of the secondary carboxamides of II is the same as in CTA/2 and its amide derivatives, in deoxy pseudoaglycone II and its tertiary amide VIII the 51,52-peptide bond undergoes a conformational change from the original cisoid to the transoid orientation. This difference between the secondary amides of II and dimethylamide VIII is reflected in their different antibacterial spectrum. The direct synthesis of the amides of deoxy pseudoaglycone II from parent CTA/2-amides by reaction with sodium borohydride is also described.

Epitope mapping of a monoclonal antibody which binds HIV-1 Gag and not the Gag-derived proteins

Monoclonal antibody (MAb) 1G12 binds the uncleaved HIV-1 Gag polypeptide (p55), but fails to recognize the final products of the proteolytic processing [Sarubbi, E. et al. (1991) FEBS Lett. 279, 265-269]. In this report we show that binding of MAb 1G12 to a 110-residue Gag fragment containing the p17-p24 cleavage site prevents proteolysis of this site by the HIV-1 protease. Competition studies with synthetic peptides have been performed to map the binding site of MAb 1G12 on Gag. The antibody recognizes a sequential epitope that spans the HIV-1 protease cleavage site; determinants located on both p17 and p24 are required for antibody binding. MAb 1G12 is also shown to lack any cross-reactivity with other HIV-1 protease cleavage sites.

Oligonucleotides complementary to the alpha-sarcin domain of 28S rRNA inhibit cell-free protein synthesis

Oligodeoxynucleotides complementary to the alpha-sarcin domain of rat 28S rRNA inhibit cell-free protein synthesis. The poly(U) translation system containing Artemia salina ribosomes was more sensitive to inhibition than the system containing rat liver ribosomes. The 21-mer, which was the most effective of the 7 oligonucleotides tested, hybridized with naked 28S rRNA. Hybridization with whole ribosomes, assayed by S1 nuclease protection, occurred only at high ionic strength or with ribosomes actively engaged in protein synthesis.

In vitro antimicrobial activity of a new antibiotic, MDL 62,879 (GE2270 A)

MDL 62,879 (GE2270 A) is a new peptide antibiotic that inhibits protein synthesis through an interaction with elongation factor Tu. MDL 62,879 was very active against gram-positive clinical isolates, particularly staphylococci and enterococci, for which MICs for 90% of isolates were < or = 0.13 micrograms/ml. It was equally active against isolates resistant to beta-lactams, erythromycin, gentamicin, and glycopeptides. It also had activity against Mycobacterium tuberculosis. MDL 62,879 had moderate bactericidal activity against staphylococci.