Principles and Practices Fostering Inclusive Excellence: Lessons from the Howard Hughes Medical Institute’s Capstone Institutions

Best-practices pedagogy in science, technology, engineering, and mathematics (STEM) aims for inclusive excellence that fosters student persistence. This paper describes principles of inclusivity across 11 primarily undergraduate institutions designated as Capstone Awardees in Howard Hughes Medical Institute’s (HHMI) 2012 competition. The Capstones represent a range of institutional missions, student profiles, and geographical locations. Each successfully directed activities toward persistence of STEM students, especially those from traditionally underrepresented groups, through a set of common elements: mentoring programs to build community; research experiences to strengthen scientific skill/ identity; attention to quantitative skills; and outreach/bridge programs to broaden the student pool. This paper grounds these program elements in learning theory, emphasizing their essential principles with examples of how they were implemented within institutional contexts. We also describe common assessment approaches that in many cases informed programming and created traction for stakeholder buy-in. The lessons learned from our shared experiences in pursuit of inclusive excellence, including the resources housed on our companion website, can inform others’ efforts to increase access to and persistence in STEM in higher education

Requirement of LaeA for Secondary Metabolism and Sclerotial Production in Aspergillus flavus

The nuclear regulator LaeA has been shown to govern production of multiple secondary metabolites in A. nidulans and A. fumigatus. Herein we examine the role of this protein in Aspergillus flavus. Similarly as in other Aspergilli, LaeA had a major effect on A. flavus secondary metabolism where ΔlaeA and over-expression laeA (OE::laeA) strains yielded opposite phenotypes resulting in decreased (increased) secondary metabolite production. The two mutant strains also exhibited striking morphological phenotypes in the loss (increase) of sclerotial production in comparison to wildtype. Growth on seed was marked by decreased (increased) conidial and aflatoxin production of the respective mutants; this was accompanied by decreased lipase activity in ΔlaeA, an enzymatic process correlated with seed maceration. Transcriptional examination of the mutants showed LaeA negatively regulates expression of its recently identified nuclear partner VeA, another global regulator of A. flavus secondary metabolites and sclerotia

NsdC and NsdD Affect Aspergillus flavus Morphogenesis and Aflatoxin Production.

The transcription factors NsdC and NsdD are required for sexual development in Aspergillus nidulans. We now show these proteins also play a role in asexual development in the agriculturally important aflatoxin (AF)-producing fungus Aspergillus flavus. We found that both NsdC and NsdD are required for production of asexual sclerotia, normal aflatoxin biosynthesis, and conidiophore development. Conidiophores in nsdC and nsdD deletion mutants had shortened stipes and altered conidial heads compared to those of wild-type A. flavus. Our results suggest that NsdC and NsdD regulate transcription of genes required for early processes in conidiophore development preceding conidium formation. As the cultures aged, the ΔnsdC and ΔnsdD mutants produced a dark pigment that was not observed in the wild type. Gene expression data showed that although AflR is expressed at normal levels, a number of aflatoxin biosynthesis genes are expressed at reduced levels in both nsd mutants. Expression of aflD, aflM, and aflP was greatly reduced in nsdC mutants, and neither aflatoxin nor the proteins for these genes could be detected. Our results support previous studies showing that there is a strong association between conidiophore and sclerotium development and aflatoxin production in A. flavus

High-Glucose-Induced Endothelial Cell Injury Is Inhibited by a Peptide Derived from Human Apolipoprotein E

lthough the importance of human apolipoprotein E (apoE) in vascular diseases has clearly been established, most of the research on apoE has focused on its role in cholesterol metabolism. In view of the observation that apoE and its functional domains impact extracellular matrix (ECM) remodeling, we hypothesized that apoE could also confer protection against ECM degradation by mechanisms independent of its role in cholesterol and lipoprotein transport. The ECM degrading enzyme, heparanase, is secreted by cells as pro-heparanase that is internalized through low-density lipoprotein (LDL) receptor-related protein-1 (LRP-1) to become enzymatically active. Both apoE and pro-heparanase bind the LRP-1. We further hypothesized that an apoE mimetic peptide (apoEdp) would inhibit the production of active heparanase by blocking LRP-1-mediated uptake of pro-heparanase and thereby decrease degradation of the ECM. To test this hypothesis, we induced the expression of heparanase by incubating human retinal endothelial cells (hRECs) with high glucose (30 mM) for 72 hours. We found that elevated expression of heparanase by high glucose was associated with increased shedding of heparan sulfate (ΔHS) and the tight junction protein occludin. Treatment of hRECs with 100 μM apoEdp in the presence of high glucose significantly reduced the expression of heparanase, shedding of ΔHS, and loss of occludin as detected by Western blot analysis. Either eye drop treatment of 1% apoEdp topically 4 times a day for 14 consecutive days or intraperitoneal injection (40 mg/kg) of apoEdp daily for 14 consecutive days in an in vivo mouse model of streptozotocin-induced diabetes inhibited the loss of tight junction proteins occludin and zona occludin- 1 (ZO-1). These findings imply a functional relationship between apoE and endothelial cell matrix because the deregulation of these molecules can be inhibited by a short peptide derived from the receptor-binding region of apoE. Thus, strategies targeting ECM-degrading enzymes could be therapeutically beneficial for treating diabetic retinopathy

Principles and Practices Fostering Inclusive Excellence: Lessons from the Howard Hughes Medical Institute’s Capstone Institutions

Best-practices pedagogy in science, technology, engineering, and mathematics (STEM) aims for inclusive excellence that fosters student persistence. This paper describes prin- ciples of inclusivity across 11 primarily undergraduate institutions designated as Capstone Awardees in Howard Hughes Medical Institute’s (HHMI) 2012 competition. The Capstones represent a range of institutional missions, student profiles, and geographical locations. Each successfully directed activities toward persistence of STEM students, especially those from traditionally underrepresented groups, through a set of common elements: men- toring programs to build community; research experiences to strengthen scientific skill/ identity; attention to quantitative skills; and outreach/bridge programs to broaden the stu- dent pool. This paper grounds these program elements in learning theory, emphasizing their essential principles with examples of how they were implemented within institutional contexts. We also describe common assessment approaches that in many cases informed programming and created traction for stakeholder buy-in. The lessons learned from our shared experiences in pursuit of inclusive excellence, including the resources housed on our companion website, can inform others’ efforts to increase access to and persistence in STEM in higher education

ApoEdp inhibits diabetic endothelial cell injury:

<p>Working model of apoEdp-mediated inhibition of hyperglycemia-induced expression of active heparanase by hRECs and related degradation of ECM.</p

ApoEdp treatment prevents retinal tight junction protein loss diabetic mice.

<p>(<b>A</b>). RNA samples isolated from different experimental groups of mice retinas were assessed for occludin-specific mRNA using one-step real-time RT-PCR. ApoEdp treatment increased retinal occludin specific mRNA>2-fold in drop-treated eyes and >2.5 fold in animals given intraperitoneal injection. (<b>B</b>). ApoEdp treatment inhibits the loss of retinal occludin-specific protein expression in streptozotocin-induced diabetic mice as determined by Western blot analysis. Significantly upregulated expression of occludin was detected in both routes (topical and intraperitoneal) in the retinas of diabetic mice.</p

ApoEdp inhibits VEGF in the retinas of diabetic mice.

<p>Total protein extracts from the mouse retinas of diabetic mice were analyzed by Western blot to detect the VEGF expression. ApoEdp treatment significantly inhibited the expression of VEGF in diabetic mice retinas.</p

ApoEdp treatment restores retinal ZO-1 protein in diabetic mice as determined by immunohistochemistry.

<p>(<b>A</b>). Immunohistochemical analysis of formalin-fixed sections of mouse retinas were stained with zona occludin-1(ZO-1) specific antibody. Mean ±SEM of ZO-1 positive cells in five high power (×400) fields were counted. The arrows in the four photos indicate a ZO-1 positive cell. (<b>B</b>): The immunohistochemical quantitative analysis of ZO-1 protein in mouse retinas. Four treatment groups were used. The number of positive cells per high-power field is determined and the (mean ±SEM) of the ZO-1 positive cells are provided. The significant difference was detected in the ZO-1 cells between the diabetic, untreated eye, and the two groups of apoEdp treated mice retinas. Treatment with either topical 1% apoEdp drops or intraperitoneal injections of apoEdp for 14 consecutive days significantly improved the relationship of the number of increased positive cells compared to the untreated, diabetic retina.</p

The protective effect of apoEdp on hRECs injured by high glucose in the cell medium.

<p>(<b>A</b>). The hRECs were treated with varying doses of 25, 50, and 100 µM of apoEdp in the presence of 30 mM D-glucose or L-glucose (osmotic control). Western blot analysis of proteins extracted from high sugar-injured cells following 72 hours of apoEdp treatment revealed dose-dependent inhibition of heparanase expression. The 100 µM apoEdp treatment inhibited (*<i>P</i>≤0.05) heparanase expression to the lowest level of the 3 treatment groups assessed. (<b>B</b>). To detect the effect of hyperglycemia-induced HS loss (Δ-HS) in hRECs treated with 100 µM of apoEdp, a commercial monoclonal antibody (3G10) specific to neoepitope generated by heparanase digestion of HSPG was used. A 100 µM apoEdp treatment significantly inhibited (*<i>P</i>≤0.05) the loss of Δ-HS in hRECs after 72 hours of high glucose treatment compared to mock treatment (high glucose but no apoEdp treatment). (<b>C</b>). ApoEdp (100 µM) treatment prevented the loss of tight junction protein occludin in hRECs under hyperglycemic conditions. The hRECs were incubated for 72 hours with or without apoEdp (100 µM) in the presence of hyperglycemia and assayed for the expression of occludin. Each value represents the mean ± SE of results in three independent experiments (*<i>P</i>≤0.05). β-actin served as the loading control.</p