Embedding art in histology teaching: Visual thinking strategies (VTS) to enhance visual literacy

BACKGROUND/AIMS Histology is a visually challenging subject for novice students. Visual thinking strategies (VTS) uses the viewing of art to improve visual literacy in classroom settings (Housen, 2002), including medical programmes (Reilly, Ring, & Duke, 2005), but has not been evaluated in histology. This project assessed the impact of VTS on students' observational skills, perceptions of histological images, and practical report marks. METHODS Participants were third-year biomedical students (n=133) studying histology in 2021. Students were shown a novel histology image and wrote their observations (pre-VTS). An experienced VTS facilitator guided students through an approximately 20-minute session exploring a never-before-seen artwork. After the VTS-activity, students were shown a new histology image and wrote their observations (post-VTS). Pre- and post-VTS descriptions were scored for measures of observational richness and compared. Responses to open-ended reflective questions were analysed by inductive thematic analysis. Report marks were compared with those from a previous year. RESULTS/CONCLUSIONS While there was no significant effect of the VTS activity on the students’ pre-/post-VTS descriptions, nor on their practical report marks, 46% of students reported that VTS changed how they viewed histological images and improved their observational skills. This study suggests that a one-off VTS activity at the beginning of a histology class can benefit students’ experience of unfamiliar microscopic images and improve enjoyment of this challenging subject. REFERENCES Housen, A.C. (2002) Aesthetic thought, critical thinking and transfer. Arts and Learning Research Journal, 18, 99-132. Reilly, J. M., Ring, J., & Duke, L. (2005) Visual thinking strategies: a new role for art in medical education. Family Medicine, 37, 250-252

Nuclear Progestin Receptor (Pgr) Knockouts in Zebrafish Demonstrate Role for Pgr in Ovulation but Not in Rapid Non-Genomic Steroid Mediated Meiosis Resumption

Progestins, progesterone derivatives, are the most critical signaling steroid for initiating final oocyte maturation (FOM) and ovulation, in order to advance fully-grown immature oocytes to become fertilizable eggs in basal vertebrates. It is well-established that progestin induces FOM at least partly through a membrane receptor and a non-genomic steroid signaling process, which precedes progestin triggered ovulation that is mediated through a nuclear progestin receptor (Pgr) and genomic signaling pathway. To determine whether Pgr plays a role in a non-genomic signaling mechanism during FOM, we knocked out Pgr in zebrafish using transcription activator-like effector nucleases (TALENs) and studied the oocyte maturation phenotypes of Pgr knockouts (Pgr-KOs). Three TALENs-induced mutant lines with different frame shift mutations were generated. Homozygous Pgr-KO female fish were all infertile while no fertility effects were evident in homozygous Pgr-KO males. Oocytes developed and underwent FOM normally in vivo in homozygous Pgr-KO female compared to the wild-type controls, but these mature oocytes were trapped within the follicular cells and failed to ovulate from the ovaries. These oocytes also underwent normal germinal vesicle breakdown (GVBD) and FOM in vitro, but failed to ovulate even after treatment with human chronic gonadotropin (HCG) or progestin (17α,20β-dihydroxyprogesterone or DHP), which typically induce FOM and ovulation in wild-type oocytes. The results indicate that anovulation and infertility in homozygous Pgr-KO female fish was, at least in part, due to a lack of functional Pgr-mediated genomic progestin signaling in the follicular cells adjacent to the oocytes. Our study of Pgr-KO supports previous results that demonstrate a role for Pgr in steroid-dependent genomic signaling pathways leading to ovulation, and the first convincing evidence that Pgr is not essential for initiating non-genomic progestin signaling and triggering of meiosis resumption

Control of oocyte release by progesterone receptor-regulated gene expression

The progesterone receptor (PGR) is a nuclear receptor transcription factor that is essential for female fertility, in part due to its control of oocyte release from the ovary, or ovulation. In all mammals studied to date, ovarian expression of PGR is restricted primarily to granulosa cells of follicles destined to ovulate. Granulosa cell expression of PGR is induced by the pituitary Luteinizing Hormone (LH) surge via mechanisms that are not entirely understood, but which involve activation of Protein Kinase A and modification of Sp1/Sp3 transcription factors on the PGR promoter. Null mutations for PGR or treatment with PGR antagonists block ovulation in all species analyzed, including humans. The cellular mechanisms by which PGR regulates ovulation are currently under investigation, with several downstream pathways having been identified as PGR-regulated and potentially involved in follicular rupture. Interestingly, none of these PGR-regulated genes has been demonstrated to be a direct transcriptional target of PGR. Rather, in ovarian granulosa cells, PGR may act as an inducible coregulator for constitutively bound Sp1/Sp3 transcription factors, which are key regulators for a discrete cohort of ovulatory genes

Pgrmc1 Knockout Impairs Oocyte Maturation in Zebrafish

Recent investigations suggest progestin receptor membrane component 1 (PGRMC1) associates with and transports a wide range of molecules such as heme, cytochromes P450, steroids with 21 carbons, membrane progestin receptor alpha (mPRα/Paqr7), epidermal growth factor receptor (EGFR), and insulin receptor. It is difficult to discriminate the true functions of PGRMC1 from the functions of its associated molecules using biochemical and pharmacological approaches. To determine the physiological function(s) of PGRMC1, we generated global knockouts for pgrmc1 (pgrmc1−/−) in zebrafish. We found a reduction in both spawning frequency and the number of embryos produced by female mutants. We also observed reduced sensitivity of fully-grown immature oocytes to a progestin hormone and a reduced number of oocytes undergone meiotic maturation both in vivo and in vitro in pgrmc1−/−. This reduced sensitivity to progestin corresponds well with significant reduced expression of mPRα, the receptor mainly responsible for mediating oocyte maturation and meiosis resumption in fish. The results provide in vivo and in vitro evidence for the physiological functions of Pgrmc1 in oocyte maturation and fertility, as well as a plausible molecular mechanism via regulation of mPRα, which in turn directly regulates oocyte maturation and affects fertility in zebrafish

The role of nuclear progesterone receptor (PGR) in regulating gene expression, morphology and function in the ovary and oviduct during the periovulatory period.

Ovulation requires sequential molecular events and structural remodelling in the ovarian follicle for the successful release of a mature oocyte into the oviduct. Critical to this process is progesterone receptor (PGR), a transcription factor highly yet transiently expressed in granulosa cells (GC) of preovulatory follicles and abundant in the oviduct. Progesterone receptor knockout (PRKO) mice are anovulatory, with a specific and complete defect in follicle rupture. Therefore, this model was used to examine the critical molecular and biochemical mechanisms necessary for successful ovulation. Progesterone is known to affect oviductal cells in vitro, but how PGR regulates oviductal structure and function is poorly understood. A systematic evaluation of ovarian and oviductal morphology during the periovulatory period revealed no structural defects in PRKO mice relative to heterozygous (PR+/-) littermates. However, in response to the LH surge/hCG treatment, ovulation only occurred in PR+/- ovaries, with numerous corpora lutea observed and cumulus oocyte complexes (COCs) in oviducts, while PRKO ovaries did not ovulate and showed entrapped COCs within large, luteinising follicles. Transplantation of PRKO ovaries into wild-type mice (PRWT) did not rescue the infertility phenotype. Therefore, although PGR is expressed in other tissues, ovarian PGR is essential for ovulation. Further experiments identified PGR-regulated processes at multiple levels. In whole ovaries 10 h post-hCG, inflammatory genes were disrupted in PRKO mice, including cytokines, endothelial adhesion factors, vasoconstrictors, T-cell antigens, and the prostaglandin synthase, Ptgs2. In GCs and COCs isolated 8 h post-hCG, microarray analyses identified 296 and 44 differentially expressed genes respectively between PRKO and PR+/- samples. Gene ontology analysis revealed associations with the processes of proteolysis, vascular remodelling/angiogenesis, inflammatory responses, cell adhesion, migration and invasion. The latter three processes were characterised in periovulatory COCs using in vitro assays and were shown to be transiently activated, peaking at ovulation then declining dramatically in COCs collected from the oviduct immediately post-ovulation. However, periovulatory PRKO and PR+/- COCs showed similar rates of adhesion, migration and invasion in the presence of collagen I. Upregulation of the chemokine receptor, Cxcr4, by LH/hCG via PGR in both GCs and COCs was validated by RT-PCR and immunohistochemistry. Mitochondrial membrane potential was altered in PRKO oocytes compared to PR+/- and therefore their developmental potential may be reduced. Further, a bioassay measuring retention of prostaglandin (PGE2) within the matrix of expanded COCs suggested that the matrix integrity of PRKO COCs may be compromised. Therefore, PGR in granulosa cells appears to have down-stream impacts on COCs. In oviducts, microarray analysis comparing gene expression in PRKO and PR+/- mice 8 h post-hCG, when P4 levels are high, identified 1003 PGR-regulated genes. Gene ontology analysis identified significant associations with the functions of cell adhesion, migration, invasion, chemotaxis, muscle contraction and vasoconstriction. Several genes were confirmed to be PGR-regulated by RT-PCR (Adamts1, Itga8 and Edn3) and were induced by LH/hCG. Therefore, the identification of novel gene targets for PGR regulation in the ovary and oviduct exposes several new, down-stream influences of PGR on inflammation, the COC and oviductal function, highlighting the essential role of PGR as master regulator in the ovary and oviduct during the periovulatory period.Thesis (Ph.D.) -- University of Adelaide, School of Paediatrics and Reproductive Health, 201

Adverse reproductive outcomes associated with fetal alcohol exposure: A systematic review

Fetal alcohol exposure results in well-characterised neuro-behavioural deficits in offspring, which form the basis for diagnosing fetal alcohol spectrum disorder. However, there is increasing interest in the full range of health complications that can arise in children and adults with this disorder. We used a systematic review approach to locate all clinical and preclinical studies across a broad range of health outcomes in offspring exposed to prenatal alcohol. Our search encompassed four databases (PubMed, CINAHL, Embase and Web of Science) and titles/abstracts from retrieved studies were screened against strict inclusion/exclusion criteria. This review specifically evaluated studies reporting on reproductive outcomes in both males and females. A total of 23 studies were included, 5 clinical and 18 preclinical. Although there was a wide range in the quality of reporting across both clinical and preclinical studies, and variable results, trends emerged amongst the reproductive measures that were investigated. In females, most studies focussed on age at first menarche/puberty onset, with evidence for a significant delay in alcohol-exposed offspring. In males, offspring exposed to prenatal alcohol had altered testosterone levels, reduced testes and accessory gland weights and reduced sperm concentration and semen volume. However, further studies are required due to the paucity of clinical studies, the narrow scope of female reproductive outcomes examined and inconsistencies in outcomes across preclinical studies. We recommend that adolescents and individuals of reproductive age diagnosed with fetal alcohol spectrum disorder be assessed for reproductive dysfunction to allow appropriate management of their reproductive health and fertility