Inhibition of Multidrug Resistance by SV40 Pseudovirion Delivery of an Antigene Peptide Nucleic Acid (PNA) in Cultured Cells

Peptide nucleic acid (PNA) is known to bind with extraordinarily high affinity and sequence-specificity to complementary nucleic acid sequences and can be used to suppress gene expression. However, effective delivery into cells is a major obstacle to the development of PNA for gene therapy applications. Here, we present a novel method for the in vitro delivery of antigene PNA to cells. By using a nucleocapsid protein derived from Simian virus 40, we have been able to package PNA into pseudovirions, facilitating the delivery of the packaged PNA into cells. We demonstrate that this system can be used effectively to suppress gene expression associated with multidrug resistance in cancer cells, as shown by RT-PCR, flow cytometry, Western blotting, and cell viability under chemotherapy. The combination of PNA with the SV40-based delivery system is a method for suppressing a gene of interest that could be broadly applied to numerous targets

CNS Delivery Via Adsorptive Transcytosis

Adsorptive-mediated transcytosis (AMT) provides a means for brain delivery of medicines across the blood-brain barrier (BBB). The BBB is readily equipped for the AMT process: it provides both the potential for binding and uptake of cationic molecules to the luminal surface of endothelial cells, and then for exocytosis at the abluminal surface. The transcytotic pathways present at the BBB and its morphological and enzymatic properties provide the means for movement of the molecules through the endothelial cytoplasm. AMT-based drug delivery to the brain was performed using cationic proteins and cell-penetrating peptides (CPPs). Protein cationization using either synthetic or natural polyamines is discussed and some examples of diamine/polyamine modified proteins that cross BBB are described. Two main families of CPPs belonging to the Tat-derived peptides and Syn-B vectors have been extensively used in CPP vector-mediated strategies allowing delivery of a large variety of small molecules as well as proteins across cell membranes in vitro and the BBB in vivo. CPP strategy suffers from several limitations such as toxicity and immunogenicity—like the cationization strategy—as well as the instability of peptide vectors in biological media. The review concludes by stressing the need to improve the understanding of AMT mechanisms at BBB and the effectiveness of cationized proteins and CPP-vectorized proteins as neurotherapeutics

Novel systemic therapies in atopic dermatitis : what do we need to fulfil the promise of a treatment revolution?

Patients with atopic dermatitis (AD) who do not adequately respond to topical therapy and phototherapy often need systemic immunomodulatory treatment to control their symptoms. Conventional systemic agents, such as ciclosporin, azathioprine, and methotrexate, have been used for decades, but there are concerns about their safety profile. There are now many novel systemic agents emerging through clinical trials, which may have great potential in the treatment of AD. Despite this, there are very few data comparing the performance of these drugs against each other. The purpose of this article is to review the current systemic therapies in AD and present an indirect comparison of systemic AD treatments using effectiveness and safety data from published randomised controlled trials, highlighting important remaining gaps in knowledge. Although the latest developments in systemic AD treatments are exciting and dearly needed, further work is required before the promise of a therapeutic revolution becomes reality

Physiological Parameters Affecting the Chemosensory Response of Tetrahymena

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Validity of first-time diagnoses of congenital epidermolysis bullosa in the Danish National Patient Registry and the Danish Pathology Registry

Mattias Hedegaard Kristensen,1 Sigrún Alba Jóhannesdóttir Schmidt,2 Line Kibsgaard,1 Mette Mogensen,3 Mette Sommerlund,1 Uffe Koppelhus1 1Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark; 2Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 3Department of Dermatology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark Purpose: Congenital epidermolysis bullosa (CEB) is a group of rare monogenic genodermatoses. Phenotypically, the diseases vary in both severity and dissemination, which complicates studies of their epidemiology. To investigate the potential of using the Danish National Patient Registry (DNPR) for epidemiological research on CEB, we examined the positive predictive value (PPV) of a first-time diagnosis of CEB.Methods: We identified patients with a record of CEB in DNPR and the Danish Pathology Registry (DPR) during January 1, 1977, until December 31, 2015. We restricted diagnoses from two dermatological departments and one regional hospital. Diagnoses in the DNPR are coded by the eighth and tenth revisions of the ICD (ICD-8 and ICD-10) and in the DPR by the Systematized Nomenclature of Medicine (SNOMED). We used clinical description in medical records, family history, histological findings, and molecular genetic investigations to validate diagnoses and classified them as rejected and confirmed. We estimated PPVs for any diagnosis, according to coding systems used, and for additional subdivisions of ICD-10 codes.Results: We identified 116 cases from the hospital departments investigated and evaluated 96 medical records for validity. The overall PPV for probable CEB was 62.5% (95% CI: 52.5–71.5). For ICD-8, ICD-10, and SNOMED codes, the PPVs were 30.8% (95% CI: 11.4–57.7), 76.7% (95% CI: 65.8–84.9), and 0.0% (95% CI: 0.0–21.7), respectively. For the ICD-10 codes, we found the highest PPVs for diagnoses arising from the dermatological departments. For subdivisions of ICD-10 codes, PPVs were high for epidermolysis bullosa simplex and dystrophica.Conclusion: The PPVs for first-time diagnoses of CEB registered in the two Danish nationwide registries investigated, DNPR and DPR, ranged from low to average. We therefore recommend that these data be used with caution and restricted to ICD-10 diagnoses from specialized dermatological departments. Keywords: Denmark, diagnosis, epidermolysis bullosa, health administrative data, registration, validit

Chemokine receptor CCR2b 64I polymorphism and its relation to CD4 T-cell counts and disease progression in a Danish cohort of HIV-infected individuals. Copenhagen AIDS cohort.

We have investigated the role of the recently described mutation in CCR2b named 64I in relation to HIV resistance, CD4 T-cell counts, and disease progression in Danish individuals by polymerase chain reaction (PCR)-based methods as well as sequenced full-length CXCR4 and CCR5 genes from HIV-infected long-term nonprogressors for possible mutations. In total, 215 Danish individuals were analyzed for 64I allele frequency; disease progression was followed in 105 HIV-1-positive homosexual Danish men from their first known positive HIV-1 test result and up to 11 years. In 87 individuals, the CD4 T-cell count was monitored closely. We found no significant difference in 64I allele frequency between HIV-1-seropositive persons (0.08), high-risk HIV-1-seronegative persons (0.11), and blood donors (0.06). No significant difference was observed in annual CD4 T-cell decline, CD4 T-cell counts at the time of AIDS, in AIDS-free survival as well as survival with AIDS, between 64I allele carriers and wild-type individuals. Among 9 long-term nonprogressors, 2 carried the 64I allele, while none of 9 fast progressors carried the 64I allele. However, this was not significantly different (p=.47). Long-term nonprogression could not be explained by CXCR4 polymorphism or other polymorphisms in the CCR5 gene than the CCR5delta32 allele. Furthermore, we were not able to detect any significant independent effect of the 64I allele on development to AIDS, overall survival, and annual CD4 T-cell decline in this cohort

Efficient in vitro inhibition of HIV-1 gag reverse transcription by peptide nucleic acid (PNA) at minimal ratios of PNA/RNA.

We have tested the inhibitory potential of peptide nucleic acid (PNA) on in vitro reverse transcription of the HIV-1 gag gene. PNA was designed to target different regions of the HIV-1 gag gene and the effect on reverse transcription by HIV-1, MMLV and AMV reverse transcriptases (RTs) was investigated. We found that a bis-PNA (parallel antisense 10mer linked to antiparallel antisense 10mer) was superior to both the parallel antisense 10mer and antiparallel antisense 10mer in inhibiting reverse transcription of the gene, thus indicating triplex formation at the target sequence. A complete arrest of reverse transcription was obtained at approximately 6-fold molar excess of the bis-PNA with respect to the gag RNA. At this molar ratio we found no effect on in vitro translation of gag RNA. A 15mer duplex-forming PNA was also found to inhibit reverse transcription at very low molar ratios of PNA/ gag RNA. Specificity of the inhibition of reverse transcription by PNA was confirmed by RNA sequencing, which revealed that all tested RTs were stopped by the PNA/RNA complex at the predicted site. We propose that the effect of PNA is exclusively due to steric hindrance, as we found no signs of RNA degradation that would indicate PNA-mediated RNase H activation of the tested RTs. In conclusion, PNA appears to have a potential to become a specific and efficient inhibitor of reverse transcription in vivo , provided sufficient intracellular levels are achievable