Project description:The study sought to investigate differences in onset and progression of renal disease in the Dahl salt-sensitive (S), S.SHR(2) congenic, and spontaneously hypertensive rat (SHR) using a time-course. The data clearly demonstrates that the locus on chromosome 2 has a major and sustained ability to attenuate renal damage. As early as week 4, significant interstitial changes were observed between the S and the congenic which preceded any significant difference in proteinuria. Gene expression profiling was performed at week 4, 12, and 20 using kidney from the S and S.SHR(2) congenic to: (1) identify expression differences of positional candidates within the QTL region; (2) correlate temporal gene expression changes between the S and congenic with degree of renal damage; and (3) identify biochemical pathways potentially involved in the attenuated renal damaged observed in the congenic. Gene pathway analysis (IngenuityÂ® Systems) performed at week 4, 12, and 20 revealed that pathways involved in cellular assembly and organization, cellular movement, and immune response were controlled differently between the S and congenic. Considering all the data, the chromosome 2 congenic appears to attenuate renal damage primarily through an altered fibrotic response. Experiment Overall Design: DNA microarray analysis was performed using Affymetrix GenechipÂ® Rat Genome 230 2.0 array at three timepoints. The chip contains 31,000 probe sets from more than 30,000 transcripts on one array. Three male S and three male S.SHR(2) congenic were selected at random from each group test for proteinruia at week 4, 12 and 20. Kidney was cut into ~ 0.5cM size cubes, suspended in RNAlater (Ambion, Austin, TX) and stored overnight at 4ÂºC. RNA was extracted using TrizolÂ® reagent (Invitrogen, Carlsbad, CA) and purified using Mini RNeasy kit (Qiagen,Valencia, CA ) according to manufacturerâs protocols. RNA quality was assessed by an OD260/280 ratio > 2.0 and visually by ethidium bromide staining on an agarose gel. Experiment Overall Design: Biotinylated cRNA was synthesized from 10 ug of total RNA using the One-Cycle Target Labeling Kit (Affymetrix, Santa Clara, CA) as directed by the user manual. cRNA quality for each sample was assessed by hybridization of 5ug adjusted kidney cRNA to Affymetrix GenechipÂ® Test3 array. Subsequently, 15ug adjusted kidney cRNA was hybridized to the GenechipÂ® Rat 230 2.0 array. Hybridized chips were automatically washed, stained and scanned at the Medical University of Ohio Bioinformatics & Proteomics/Genomics Program gene array facility using Affymetrix equipment.

Project description:Banking of high-quality placental tissue specimens will enable biomarker discovery and molecular studies on diseases involving placental dysfunction. Systematic studies aimed at developing feasible standardized methodology for placental collection for genomic analyses are lacking. To determine the acceptable timeframe for placental collection, we collected multiple samples from first and third trimester placentas at serial time points 0-120 minutes after delivery, simultaneously comparing the traditional snap-freeze technique to collection in commercial solutions designed to preserve RNA (RNAlaterTM, Ambion), and DNA (DNAgard®, Biomatrica). The performance of RNAlater for preserving DNA was also tested. Nucleic acid quality was assessed by determining the RNA integrity number (RIN) and genome-wide expression and DNA methylation microarray profiling. We found that samples collected in RNAlater had higher and more consistent RINs compared to snap frozen tissue, with similar RINs obtained for tissue collected in RNAlater as large (1 cm3) and small (~0.1 cm3) tissue pieces. RNAlater appeared to better stabilize the time zero gene expression pattern compared to snap freezing for first trimester placenta. Microarray DNA methylation analysis showed that overall the DNA methylation profiles remained quite stable over a two hour time period after removal of the placenta from the uterus, with the DNAgard condition being superior to both snap freezing and RNAlater. The collection of placental samples in RNAlater and DNAgard is simple, and eliminates the need for liquid nitrogen or a freezer on-site. Moreover, the quality of the nucleic acids and the resulting data from samples collected in these preservation solutions is actually higher than that from samples collected using the traditional snap-freeze method. Thus, this new approach to placental sample collection is both easier to implement in busy clinical environments and yields higher quality data. 72 samples

Project description:Banking of high-quality placental tissue specimens will enable biomarker discovery and molecular studies on diseases involving placental dysfunction. Systematic studies aimed at developing feasible standardized methodology for placental collection for genomic analyses are lacking. To determine the acceptable timeframe for placental collection, we collected multiple samples from first and third trimester placentas at serial time points 0-120 minutes after delivery, simultaneously comparing the traditional snap-freeze technique to collection in commercial solutions designed to preserve RNA (RNAlaterTM, Ambion), and DNA (DNAgard®, Biomatrica). The performance of RNAlater for preserving DNA was also tested. Nucleic acid quality was assessed by determining the RNA integrity number (RIN) and genome-wide expression and DNA methylation microarray profiling. We found that samples collected in RNAlater had higher and more consistent RINs compared to snap frozen tissue, with similar RINs obtained for tissue collected in RNAlater as large (1 cm3) and small (~0.1 cm3) tissue pieces. RNAlater appeared to better stabilize the time zero gene expression pattern compared to snap freezing for first trimester placenta. Microarray DNA methylation analysis showed that overall the DNA methylation profiles remained quite stable over a two hour time period after removal of the placenta from the uterus, with the DNAgard condition being superior to both snap freezing and RNAlater. The collection of placental samples in RNAlater and DNAgard is simple, and eliminates the need for liquid nitrogen or a freezer on-site. Moreover, the quality of the nucleic acids and the resulting data from samples collected in these preservation solutions is actually higher than that from samples collected using the traditional snap-freeze method. Thus, this new approach to placental sample collection is both easier to implement in busy clinical environments and yields higher quality data. 48 samples

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Next Generation Sequencing Facilitates Quantitative Analysis of Normal Human Kidney Transcriptomes

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