The K-INBRE symposium: a 10-institution collaboration to improve undergraduate education.

The Kansas-IDeA Network of Biomedical Research Excellence (K-INBRE) is an infrastructure-building program funded by the National Institute of General Medical Sciences. Undergraduate education, through undergraduate research, is a key component of the program. The K-INBRE network includes 10 higher education institutions in Kansas and northern Oklahoma, with over 1,000 student participants in 16 yr. Since 2003, the K-INBRE has held an annual state-wide research symposium that includes national and regional speakers and provides a forum for undergraduates to give platform and poster presentations. The symposium is well attended by K-INBRE participants and has grown to a size of over 300 participants per year from all 10 K-INBRE schools. Two surveys were distributed to students and mentors to assess the impact of the symposium on student learning. Surveys (153) were distributed to students who participated in K-INBRE from 2013 through 2015 with a 51% response rate. Mentors were surveyed with a response of 111 surveys out of 161. Survey results indicate that students and mentors alike find the symposium to be beneficial and enriching of the student experience. Almost 80% of student respondents indicated that their participation in the symposium fostered appreciation of research. In short, the K-INBRE symposium provides a unique opportunity for students to gain experience in collecting, preparing, and communicating research in a professional environment. The collaborative experience of the annual K-INBRE symposium, the impact it has on student learning, and how it has influenced the research culture at our 10 institutions will be described.

Altered microRNA expression patterns during the initiation and promotion stages of neonatal diethylstilbestrol-induced dysplasia/neoplasia in the hamster (Mesocricetus auratus) uterus.

Treatment of Syrian hamsters on the day of birth with the prototypical endocrine disruptor and synthetic estrogen, diethylstilbestrol (DES), leads to 100% occurrence of uterine hyperplasia/dysplasia in adulthood, a large proportion of which progress to neoplasia (endometrial adenocarcinoma). Consistent with our prior gene expression analyses at the mRNA and protein levels, we now report (based on microarray, real-time polymerase chain reaction, and in situ hybridization analyses) that progression of the neonatal DES-induced dysplasia/neoplasia phenomenon in the hamster uterus also includes a spectrum of microRNA expression alterations (at both the whole-organ and cell-specific level) that differ during the initiation (upregulated miR-21, 200a, 200b, 200c, 29a, 29b, 429, 141; downregulated miR-181a) and promotion (downregulated miR-133a) stages of the phenomenon. The biological processes targeted by those differentially expressed miRNAs include pathways in cancer and adherens junction, plus regulation of the cell cycle, apoptosis, and miRNA functions, all of which are consistent with our model system phenotype. These findings underscore the need for continued efforts to identify and assess both the classical genetic and the more recently recognized epigenetic mechanisms that truly drive this and other endocrine disruption phenomena.

Altered gene expression patterns during the initiation and promotion stages of neonatally diethylstilbestrol-induced hyperplasia/dysplasia/neoplasia in the hamster uterus.

Neonatal treatment of hamsters with diethylstilbestrol (DES) induces uterine hyperplasia/dysplasia/neoplasia (endometrial adenocarcinoma) in adult animals. We subsequently determined that the neonatal DES exposure event directly and permanently disrupts the developing hamster uterus (initiation stage) so that it responds abnormally when it is stimulated with estrogen in adulthood (promotion stage). To identify candidate molecular elements involved in progression of the disruption/neoplastic process, we performed: (1) immunoblot analyses and (2) microarray profiling (Affymetrix Gene Chip System) on sets of uterine protein and RNA extracts, respectively, and (3) immunohistochemical analysis on uterine sections; all from both initiation stage and promotion stage groups of animals. Here we report that: (1) progression of the neonatal DES-induced hyperplasia/dysplasia/neoplasia phenomenon in the hamster uterus involves a wide spectrum of specific gene expression alterations and (2) the gene products involved and their manner of altered expression differ dramatically during the initiation vs. promotion stages of the phenomenon.

Neonatal diethylstilbestrol exposure disrupts female reproductive tract structure/function via both direct and indirect mechanisms in the hamster.

We assessed neonatal diethylstilbestrol (DES)-induced disruption at various endocrine levels in the hamster. In particular, we used organ transplantation into the hamster cheek pouch to determine whether abnormalities observed in the post-pubertal ovary are due to: (a) a direct (early) mechanism or (b) an indirect (late) mechanism that involves altered development and function of the hypothalamus and/or pituitary. Of the various disruption endpoints and attributes assessed: (1) some were consistent with the direct mechanism (altered uterine and cervical dimensions/organization, ovarian polyovular follicles, vaginal hypospadius, endometrial hyperplasia/dysplasia); (2) some were consistent with the indirect mechanism (ovarian/oviductal salpingitis, cystic ovarian follicles); (3) some were consistent with a combination of the direct and indirect mechanisms (altered endocrine status); and (4) the mechanism(s) for one (lack of corpora lutea) was uncertain. This study also generated some surprising observations regarding vaginal estrous assessments as a means to monitor periodicity of ovarian function in the hamster.

Differential progression of neonatal diethylstilbestrol-induced disruption of the hamster testis and seminal vesicle.

The synthetic estrogen diethylstilbestrol (DES) is now recognized as the prototypical endocrine disruptor. Using a hamster experimental system, we performed a detailed temporal assessment of how neonatal DES-induced disruption progresses in the testis compared to the seminal vesicle. Both morphological and Western blot analyses confirmed that neonatal DES exposure alters androgen responsiveness in the male hamster reproductive tract. We also determined that the disruption phenomenon in the male hamster is manifest much earlier in the seminal vesicle than in the testis and that testis disruption often occurs differently between the pair of organs in a given animal. In the neonatally DES-exposed seminal vesicle, histopathological effects included: (1) general atrophy, (2) lack of exocrine products, (3) epithelial dysplasia, (4) altered organization of stromal cells and extracellular matrix, and (5) striking infiltration with polymorphonuclear leukocytes. Also, the morphological disruption phenomenon in the seminal vesicle was accompanied by a range of up-regulation and down-regulation responses in the whole organ levels of various proteins.

Neonatal exposure to diethylstilbestrol leads to impaired action of androgens in adult male hamsters.

Neonatal treatment with diethylstilbestrol (DES) leads to disruption of spermatogenesis in adult animals after apparently normal testicular development during puberty indicating aberrant androgen action in DES-exposed adult hamsters. The present study determined the effects of exogenous androgens in neonatally DES-exposed hamsters. Exogenous androgens failed to reverse the disruption of spermatogenesis in DES-exposed animals. Neonatal DES exposure caused a significant decrease in seminal vesicle weight, and abnormal histology. While exogenous androgens caused a significant increase in seminal vesicle weight in control animals, they failed to restore the seminal vesicle weight and normal histology in DES-exposed animals. Northern blot and/or RT-PCR analysis revealed that (1) AR, ERalpha and ERbeta mRNA levels were unchanged in DES-exposed animals, and (2) mRNA levels for the AR-responsive genes calreticulin, SEC-23B, and ornithine decarboxylase were significantly decreased in DES-exposed animals. Our results suggest that neonatal DES exposure impairs the action of androgens on target organs in male hamsters.

Diethylstilbestrol versus estradiol as neonatal disruptors of the hamster (Mesocricetus auratus) cervix.

The synthetic estrogen diethylstilbestrol (DES) is an established, estrogenic endocrine disruptor (ED). The Syrian golden hamster (Mesocricetus auratus) offers some unique advantages as an experimental system to investigate the perinatal ED action of DES and other estrogenic EDs. Previous analyses regarding the consequences of neonatal administration (100 microg) of DES versus estradiol-17beta (E2) showed that DES had a more potent disruptive effect on morphogenesis and gene expression in the uterus, oviduct, and ovary as well as in the testis and male accessory organs. The objectives of the present study were to describe the histopathological consequences of the two neonatal treatment regimens in the hamster cervix and to compare them with our previous observations in the hamster uterus. As previously found in the hamster uterus, DES was more potent than E2 as a neonatal disruptor of the hamster cervix in prepubertal animals and in ovarian-intact adult animals. However, the cervix-versus-uterus scenario diverged in animals that were ovariectomized prepubertally and then chronically stimulated with natural estrogen (E2). We confirmed previous observations that neonatal exposure to DES, but not to E2, permanently alters estrogen responsiveness in the adult hamster uterus, but neither neonatal treatment regimen affected estrogen responsiveness in the adult hamster cervix. These results suggest that an unidentified ovarian factor influences the extent of neonatal DES-induced disruption of the cervix, but not of the uterus, in hamsters.

Gene discovery in the hamster: a comparative genomics approach for gene annotation by sequencing of hamster testis cDNAs.

BACKGROUND: Complete genome annotation will likely be achieved through a combination of computer-based analysis of available genome sequences combined with direct experimental characterization of expressed regions of individual genomes. We have utilized a comparative genomics approach involving the sequencing of randomly selected hamster testis cDNAs to begin to identify genes not previously annotated on the human, mouse, rat and Fugu (pufferfish) genomes. RESULTS: 735 distinct sequences were analyzed for their relatedness to known sequences in public databases. Eight of these sequences were derived from previously unidentified genes and expression of these genes in testis was confirmed by Northern blotting. The genomic locations of each sequence were mapped in human, mouse, rat and pufferfish, where applicable, and the structure of their cognate genes was derived using computer-based predictions, genomic comparisons and analysis of uncharacterized cDNA sequences from human and macaque. CONCLUSION: The use of a comparative genomics approach resulted in the identification of eight cDNAs that correspond to previously uncharacterized genes in the human genome. The proteins encoded by these genes included a new member of the kinesin superfamily, a SET/MYND-domain protein, and six proteins for which no specific function could be predicted. Each gene was expressed primarily in testis, suggesting that they may play roles in the development and/or function of testicular cells.

Developing a laboratory animal model for perinatal endocrine disruption: the hamster chronicles.

At the biomedical, regulatory, and public level, considerable concern surrounds the concept that inappropriate exposure to endocrine-disrupting chemicals, especially during the prenatal and/or neonatal period, may disrupt normal reproductive tract development and adult function. The intent of this review was to 1. Describe some unique advantages of the hamster for perinatal endocrine disruptor (ED) studies, 2. Summarize the morphological and molecular consequences of exposure to the established perinatal ED, diethylstilbestrol, in the female and male hamster, 3. Present some new, histomorphological insight into the process of neonatal diethylstilbestrol-induced disruption in the hamster uterus, and 4. Introduce recent efforts and future plans to evaluate the potency and mechanism of action of other putative EDs in the hamster experimental system. Taken together, the findings indicate that the hamster represents a unique and sensitive in vivo system to probe the phenomenon of endocrine disruption. The spectrum of candidate endpoints includes developmental toxicity, neoplasia, and more subtle endpoints of reproductive dysfunction.