Huntington's disease is a severely disabling and lethal neurodegenerative disorder The development of a non-human primate model for the disease would be invaluable in understanding its pathology and in developing therapeutic strategies, and this paper reports a significant step towards that goal is reported in this issue Transgenic rhesus macaque monkeys that express the first exon of the polyglutamine-expanded human huntingtin gene develop key features of Huntington's disease, including dystonia and chorea The data suggest that it will be feasible to generate non-human primate models for Huntington's disease and possibly for other neurodegenerative disorders, where rodent models may not reflect the brain changes and behavioural features of the human disease Non-human primates are valuable for modelling human disorders and for developing therapeutic strategies; however, little work has been reported in establishing transgenic non-human primate models of human diseases Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder characterized by motor impairment, cognitive deterioration and psychiatric disturbances followed by death within 10–15 years of the onset of the symptoms1,2,3,4 HD is caused by the expansion of cytosine-adenine-guanine (CAG, translated into glutamine) trinucleotide repeats in the first exon of the human huntingtin (HTT) gene5 Mutant HTT with expanded polyglutamine (polyQ) is widely expressed in the brain and peripheral tissues2,6, but causes selective neurodegeneration that is most prominent in the striatum and cortex of the brain Although rodent models of HD have been developed, these models do not satisfactorily parallel the brain changes and behavioural features observed in HD patients Because of the close physiological7, neurological and genetic similarities8,9 between humans and higher primates, monkeys can serve as very useful models for understanding human physiology and diseases10,11 Here we report our progress in developing a transgenic model of HD in a rhesus macaque that expresses polyglutamine-expanded HTT Hallmark features of HD, including nuclear inclusions and neuropil aggregates, were observed in the brains of the HD transgenic monkeys Additionally, the transgenic monkeys showed important clinical features of HD, including dystonia and chorea A transgenic HD monkey model may open the way to understanding the underlying biology of HD better, and to the development of potential therapies Moreover, our data suggest that it will be feasible to generate valuable non-human primate models of HD and possibly other human genetic diseases

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Towards a transgenic model of Huntington’s disease in a non-human primate

This review is a short update on the diversity of swine biomedical models and the importance of genomics in their continued development. The swine has been used as a major mammalian model for human studies because of the similarity in size and physiology, and in organ development and disease progression. The pig model allows for deliberately timed studies, imaging of internal vessels and organs using standard human technologies, and collection of repeated peripheral samples and, at kill, detailed mucosal tissues. The ability to use pigs from the same litter, or cloned or transgenic pigs, facilitates comparative analyses and genetic mapping. The availability of numerous well defined cell lines, representing a broad range of tissues, further facilitates testing of gene expression, drug susceptibility, etc. Thus the pig is an excellent biomedical model for humans. For genomic applications it is an asset that the pig genome has high sequence and chromosome structure homology with humans. With the swine genome sequence now well advanced there are improving genetic and proteomic tools for these comparative analyses. The review will discuss some of the genomic approaches used to probe these models. The review will highlight genomic studies of melanoma and of infectious disease resistance, discussing issues to consider in designing such studies. It will end with a short discussion of the potential for genomic approaches to develop new alternatives for control of the most economically important disease of pigs, porcine reproductive and respiratory syndrome (PRRS), and the potential for applying knowledge gained with this virus for human viral infectious disease studies.

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Advances in swine biomedical model genomics.

Alzheimer's disease is the most common cause of senile dementia in the United States and Europe. At present, there is no effective treatment. Given the disease's prevalence and poor prognosis, the development of animal models has been a high research priority. Transgenic modeling has been pursued on the basis of the amyloid hypothesis and has taken advantage of mutations in the amyloid precursor protein and the presenilins that cause familial forms of Alzheimer's disease. Modeling has been most aggressively pursued in mice, for which the techniques of genetic modification are well developed. Transgenic mouse models now exist that mimic a range of Alzheimer's disease–related pathologies. Although none of the models fully replicates the human disease, the models have contributed significant insights into the pathophysiology of β-amyloid toxicity, particularly with respect to the effects of different β-amyloid species and the possible pathogenic role of β-amyloid oligomers. They have also been widely used in the preclinical testing of potential therapeutic modalities and have played a pivotal role in the development of immunotherapies for Alzheimer's disease that are currently in clinical trials. These models will, without a doubt, continue to play central roles in preclinical testing and be used as tools for developing insights into the biological basis of Alzheimer's disease. Mt Sinai J Med 77:69&–81, 2010. © 2010 Mount Sinai School of Medicine

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Transgenic mouse models of Alzheimer's disease.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/j.febslet.2013.05.010

The amyloid precursor protein: a biochemical enigma in brain development, function and disease.

Background: Global analysis of the genome, transcriptome, and proteome is facilitated by the recent development of tools for large-scale, highly parallel analysis. We describe a novel nucleic acid amplification system that generates products by several methods. 3′-Ribo-SPIA™ primes cDNA synthesis at the 3′ polyA tail, and whole transcript (WT)-Ribo-SPIA primes cDNA synthesis across the full length of the transcripts and thus provides whole-transcriptome amplification, independent of the 3′ polyA tail. Methods: We developed isothermal linear nucleic acid amplification systems, which use a single chimeric primer, for amplification of DNA (SPIA) and RNA (Ribo-SPIA). The latter allows mRNA amplification from as little as 1 ng of total RNA. Amplification efficiency was calculated based on the delta threshold cycle between nonamplified cDNA targets and amplified cDNA. The amounts and quality of total RNA and amplification products were determined after purification of the amplification products. GeneChip® array gene expression profiling and real-time PCR were used to test the accuracy and reproducibility of the method. Quantification of cDNA products (before and after amplification) at the 2 loci along the transcripts was used to assess product length (for evaluation of the 3′-initiated Ribo-SPIA) and equal representation throughout the length of the transcript (for evaluation of the whole transcript amplification system, WT-Ribo-SPIA™). Results: Ribo-SPIA–based global RNA amplification exhibited linearity over 6 orders of magnitude of transcript abundance and generated microgram amounts of amplified cDNA from as little as 1 ng of total RNA. Conclusions: The described methods enable comprehensive gene expression profiling and analysis from limiting biological samples. The WT-Ribo-SPIA procedure, which enables amplification of non–polyA-tailed RNA, is suitable for amplification and gene expression analysis of both eukaryotic and prokaryotic biological samples.

Novel Isothermal, Linear Nucleic Acid Amplification Systems for Highly Multiplexed Applications

Differential mRNA expression patterns were evaluated between germinal vesicle oocytes (pgvo), four-cell (p4civv), blastocyst (pblivv), and in vitro-produced four-cell (p4civp) and in vitro-produced blastocyst (pblivp) stage embryos to determine key transcripts responsible for early embryonic development in the pig. Five comparisons were made: pgvo to p4civv, p4civv to pblivv, pgvo to pblivv, p4civv to p4civp, and pblivv to pblivp. ANOVA (P < 0.05) was performed with the Benjamini and Hochberg false-discovery-rate multiple correction test on each comparison. A comparison of pgvo to p4civv, p4civv to pblivv, and pgvo to pblivv resulted in 3214, 1989, and 4528 differentially detected cDNAs, respectively. Real-time PCR analysis on seven transcripts showed an identical pattern of changes in expression as observed on the microarrays, while one transcript deviated at a single cell stage. There were 1409 and 1696 differentially detected cDNAs between the in vitro- and in vivo-produced embryos at the four-cell and blastocyst stages, respectively, without the Benjamini and Hochberg false-discovery-rate multiple correction test. Real-time polymerase chain reaction (PCR) analysis on four genes at the four-cell stage showed an identical pattern of gene expression as found on the microarrays. Real-time PCR analysis on four of five genes at the blastocyst stage showed an identical pattern of gene expression as found on the microarrays. Thus, only 1 of the 39 comparisons of the pattern of gene expression exhibited a major deviation between the microarray and the real-time PCR. These results illustrate the complex mechanisms involved in pig early embryonic development.

https://bioone.org/journals/Biology-of-Reproduction/volume-72/issue-6/biolreprod.104.037952/Transcriptional-Profiling-of-Pig-Embryogenesis-by-Using-a-15-K/10.1095/biolreprod.104.037952.pdf

Transcriptional Profiling of Pig Embryogenesis by Using a 15-K Member Unigene Set Specific for Pig Reproductive Tissues and Embryos

Alzheimer's disease (AD) is a devastating neurodegenerative disorder that affects a large and growing number of elderly individuals. In addition to idiopathic disease, AD is also associated with autosomal dominant inheritance, which causes a familial form of AD (FAD). Some instances of FAD have been linked to mutations in the β-amyloid protein precursor (APP). Although there are numerous mouse AD models available, few rat AD models, which have several advantages over mice, have been generated. Fischer 344 rats expressing human APP driven by the ubiquitin-C promoter were generated via lentiviral vector infection of Fischer 344 zygotes. We generated two separate APP-transgenic rat lines, APP21 and APP31. Serum levels of human amyloid-beta (Aβ)40 were 298 pg/ml for hemizygous and 486 pg/ml for homozygous APP21 animals. Serum Aβ42 levels in APP21 homozygous rats were 135 pg/ml. Immunohistochemistry in brain showed that the human APP transgene was expressed in neurons, but not in glial cells. These findings were consistent with independent examination of enhanced green fluorescent protein (eGFP) in the brains of eGFP-transgenic rats. APP21 and APP31 rats expressed 7.5- and 3-times more APP mRNA, respectively, than did wild-type rats. Northern blots showed that the human APP transgene, driven by the ubiquitin-C promoter, is expressed significantly more in brain, kidney and lung compared to heart and liver. A similar expression pattern was also seen for the endogenous rat APP. The unexpected similarity in the tissue-specific expression patterns of endogenous rat APP and transgenic human APP mRNAs suggests regulatory elements within the cDNA sequence of APP. This manuscript describes the generation of APP-transgenic inbred Fischer 344 rats. These are the first human AD model rat lines generated by lentiviral infection. The APP21 rat line expresses high levels of human APP and could be a useful model for AD. Tissue-specific expression in the two transgenic rat lines and in wild-type rats contradicts our current understanding of APP gene regulation. Determination of the elements that are responsible for tissue-specific expression of APP may enable new treatment options for AD.

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Development of transgenic rats producing human β-amyloid precursor protein as a model for Alzheimer's disease: Transgene and endogenous APP genes are regulated tissue-specifically

Motility and acrosomal integrity comparisons between electro-ejaculated and epididymal ram sperm after exposure to a range of anisosmotic solutions, cryoprotective agents and low temperatures

The objective of this study was to determine the effects of various physical interventions such as centrifugation regimes, Percoll gradient separation, and repeated pipetting on various viability parameters of epididymal sperm of Fischer 344 (F-344) and Sprague-Dawley (SD) rat strains. Three experiments were conducted. In experiment 1, sperm motility and acrosomal and membrane integrity were compared after exposing sperm samples to 200, 400, 600, and 800 x g centrifugal forces for 5, 10, or 15 minutes. In experiment 2, sperm motility and acrosomal and membrane integrity were compared after passing them through a Percoll separation using centrifugal forces of 600, 800, 1000, and 1200 x g for either 15 or 30 minutes. In experiment 3, the effect of repeated pipetting (2, 4, 6, 8, and 10 times) on motility and membrane integrity of rat sperm was compared with that on mouse, ram, bull, and boar sperm. The results revealed that both F-344 and SD rat sperm motility and membrane integrity were significantly affected by centrifugation (P .05). Sperm from SD rats also had higher motility and membrane integrity loss than did sperm from F-344 rats after centrifugation and pipetting (P .05). Repeated pipetting had a dramatic adverse effect on both rat and mouse sperm motility (P .05). These data suggest that rat sperm have unique properties that need to be considered during centrifugation, Percoll gradient separation, and pipetting procedures.

https://onlinelibrary.wiley.com/doi/pdf/10.2164/jandrol.107.004333

Cansu Agca

Papers

Transcriptional Profiling of Pig Embryogenesis by Using a 15-K Member Unigene Set Specific for Pig Reproductive Tissues and Embryos

Development of transgenic rats producing human β-amyloid precursor protein as a model for Alzheimer's disease: Transgene and endogenous APP genes are regulated tissue-specifically

Motility and acrosomal integrity comparisons between electro-ejaculated and epididymal ram sperm after exposure to a range of anisosmotic solutions, cryoprotective agents and low temperatures

Various Physical Stress Factors on Rat Sperm Motility, Integrity of Acrosome, and Plasma Membrane

Effects of nonylphenol on motility and subcellular elements of epididymal rat sperm.