Project description:Current human reproductive risk assessment methods rely on semen and serum hormone analyses, which are not easily comparable to the histopathological endpoints and mating studies used in animal testing. Because of these limitations, there is a need to develop universal evaluations that reliably reflect male reproductive function. We hypothesized that toxicant-induced testicular injury can be detected in sperm using mRNA transcripts as indicators of insult. To test this, we exposed adult male Fischer 344 rats to low doses of model testicular toxicants and classically characterized the testicular injury while simultaneously evaluating sperm mRNA transcripts from the same animals. Overall, this study aimed to: 1) identify sperm transcripts altered after exposure to the model testicular toxicant, 2,5-hexanedione (HD) using microarrays; 2) expand on the HD-induced transcript changes in a comprehensive time course experiment using qRT-PCR arrays; and 3) test these injury indicators after exposure to another model testicular toxicant, carbendazim (CBZ). Microarray analysis of HD-treated adult Fischer 344 rats identified 128 altered sperm mRNA transcripts when compared to control using linear models of microarray analysis (q < 0.05). All transcript alterations disappeared after 3 months of post-exposure recovery. In the time course experiment, time-dependent alterations were observed for 12 candidate transcripts selected from the microarray data based upon fold change and biological relevance, and 8 of these transcripts remained significantly altered after the 3-month recovery period (p < 0.05). In the last experiment, 8 candidate transcripts changed after exposure to CBZ (p < 0.05). The two testicular toxicants produced distinct molecular signatures with only 4 overlapping transcripts between them, each occurring in opposite directions. Overall, these results suggest that sperm mRNA transcripts are indicators of low dose toxicant-induced testicular injury in the rat. Rats were exposed to sub-chronic low doses of the Sertoli cell toxicant 2,5-hexanedione (HD) or water (control for HD) for 3 months. Some rats in each group underwent 3 months of post-exposure recovery.
Project description:Current human reproductive risk assessment methods rely on semen and serum hormone analyses, which are not easily comparable to the histopathological endpoints and mating studies used in animal testing. Because of these limitations, there is a need to develop universal evaluations that reliably reflect male reproductive function. We hypothesized that toxicant-induced testicular injury can be detected in sperm using mRNA transcripts as indicators of insult. To test this, we exposed adult male Fischer 344 rats to low doses of model testicular toxicants and classically characterized the testicular injury while simultaneously evaluating sperm mRNA transcripts from the same animals. Overall, this study aimed to: 1) identify sperm transcripts altered after exposure to the model testicular toxicant, 2,5-hexanedione (HD) using microarrays; 2) expand on the HD-induced transcript changes in a comprehensive time course experiment using qRT-PCR arrays; and 3) test these injury indicators after exposure to another model testicular toxicant, carbendazim (CBZ). Microarray analysis of HD-treated adult Fischer 344 rats identified 128 altered sperm mRNA transcripts when compared to control using linear models of microarray analysis (q < 0.05). All transcript alterations disappeared after 3 months of post-exposure recovery. In the time course experiment, time-dependent alterations were observed for 12 candidate transcripts selected from the microarray data based upon fold change and biological relevance, and 8 of these transcripts remained significantly altered after the 3-month recovery period (p < 0.05). In the last experiment, 8 candidate transcripts changed after exposure to CBZ (p < 0.05). The two testicular toxicants produced distinct molecular signatures with only 4 overlapping transcripts between them, each occurring in opposite directions. Overall, these results suggest that sperm mRNA transcripts are indicators of low dose toxicant-induced testicular injury in the rat.
Project description:Late-life intervention with a soy-enriched diet attenuated age-dependent changes in renal structure and dysfunction in male Fischer 344 rats.
Project description:Acute rejection episodes trigger chronic renal allograft vasculopathy. Numerous leukocytes, predominantly monocytes, accumulate in graft blood vessels during reversible acute rejection preceding chronic rejection of rat kidneys. We speculate that they contribute to transplant vasculopathy and set out to characterize them. Allogeneic renal transplantation was performed in the Fischer 344 to Lewis rat strain combination, Lewis isografts served as controls. Leukocytes were harvested by intensive perfusion of graft blood vessels and subjected to flow cytometry, quantitative RT-PCR and genome-wide transcriptional profiling.
Project description:Transcriptomic data obtained by RNA-seq from male Fischer 344 rats treated with furan and 3-methylfuran were compared and contrasted. Microarray data from the same rats treated with furan was also used to compare microarray to RNA seq analysis.
Project description:This study was performed to characterize the gene expression profile of rat peritoneal mesothelioma (RPM) formation following treatment of Fischer 344 rats with o-nitrotoluene (o-NT) or bromochloracetic acid (BCA). Keywords: Rat, Mesotheliomas, Bromochloractetic acid, o-Nitrotoluene, Carcinogenesis, Microarray
Project description:Cannabis is commonly used amongst reproductive age males. Our group and others have shown that chronic delta-9-tetrahydrocannabinol (THC) use adversely impacts male fertility, but less is known about the potential reversibility of these changes. Our study’s objective was to determine if THC discontinuation mitigates THC-associated changes in male reproductive health using a rhesus macaque (RM) model of daily THC edible consumption over a 280-day period (4 spermatogenic cycles). Testicular volume, serum male hormones, semen parameters, sperm DNA fragmentation, seminal fluid proteomics, and whole genome bisulfite sequencing (WGBS) of sperm DNA were assessed at pre-THC, moderate-THC, and heavy-THC dosing, and at 70 and 140 days after THC discontinuation. Chronic THC use resulted in significant testicular atrophy, increased gonadotropins, decreased serum sex steroids, and increased DNA fragmentation. THC discontinuation led to partial recovery of testicular volume, sex steroids and sperm DNA integrity. Seminal fluid proteome analysis revealed differential expression of proteins enriched for processes related to cellular secretion, immune response, and fibrinolysis. WGBS identified significant differential methylation in heavy-THC versus pre-THC sperm, with partial restoration of methylation after discontinuation of THC. Genes associated with differentially methylated regions (DMRs) were enriched for pathways involved in nervous system development and function. This is the first study demonstrating that chronic THC use in RMs adversely impacts male reproductive health, methylation of genes involved in development, and expression of proteins important for male fertility. THC discontinuation improves impacts to male fertility, including partial restoration of THC-associated sperm DMRs in genes important for development.
Project description:We used Reduced Representation Bisulfite Sequencing (RRBS) to comprehensively investigate the impact of chronic, low-dose Cd exposure on mice spermatozoa DNA methylation. Adult male C57BL/J6 mice were provided water with or without cadmium chloride. We purified genomic DNA from sperm samples collected after nine weeks of treatment. We found 1,788 differentially methylated sites present at regulatory regions in sperm of mice exposed to chronic, low-dose of Cd compared to vehicle (control) mice. Our results present a comprehensive analysis of the sperm methylome in response to chronic Cd exposure
Project description:This study assessed the implications of a 14 day sub-chronic exposure of ethinylestradiol (EE2; 1.0 or 10.0 µg/L EE2) on male medaka fertility, testicular histology and testicular gene expression. The findings demonstrate that a 14 day exposure to EE2 induced impaired male reproductive capacity and time- and dose-dependent alterations in testicular morphology and gene expression. The average fertilization rate/day following the exposure for control, 1.0 and 10.0 µg/L EE2 was 91.3% (±4.4), 62.8% (±8.3) and 28.8% (±5.8), respectively. The testicular morphologic alterations observed include increased germ cell apoptosis, decreased germinal epithelium and thickening of the interstitium. The morphologic changes observed were highly associated with gene expression changes observed using a medaka-specific microarray. A pathway analysis of the differentially expressed genes emphasized genes and pathways associated with apoptosis, cell cycle and proliferation, collagen production/extracellular matrix organization, hormone signaling, male reproduction and protein ubiquitination among others.
Project description:Acute rejection episodes trigger chronic renal allograft vasculopathy. Numerous leukocytes, predominantly monocytes, accumulate in graft blood vessels during reversible acute rejection preceding chronic rejection of rat kidneys. We speculate that they contribute to transplant vasculopathy and set out to characterize them. Allogeneic renal transplantation was performed in the Fischer 344 to Lewis rat strain combination, Lewis isografts served as controls. Leukocytes were harvested by intensive perfusion of graft blood vessels and subjected to flow cytometry, quantitative RT-PCR and genome-wide transcriptional profiling. Kidneys of LEW and F344 rats were transplanted in LEW rats. Five biological replicates were performed for both isogenic and allogenic transplantation. Transcriptomes of allogenics were compared to isogenics on 5 dual-color hybridizations.