Improving Instructional Fitness Requires Change.

Transmission of information has benefitted from a breathtaking level of innovation and change over the past 20 years; however, instructional methods within colleges and universities have been slow to change. In the article, we present a novel framework to structure conversations that encourage innovation, change, and improvement in our system of higher education, in general, and our system of biology education, specifically. In particular, we propose that a conceptual model based on evolutionary landscapes in which fitness is replaced by educational effectiveness would encourage educational improvement by helping to visualize the multidimensional nature of education and learning, acknowledge the complexity and dynamism of the educational landscape, encourage collaboration, and stimulate experimental thinking about how new approaches and methodology could take various fields associated with learning, to more universal fitness optima.

Chick Embryonic Primary Astrocyte Cultures Provide an Effective and Scalable Model for Authentic Research in a Laboratory Class.

Cell culture provides an impactful tool for undergraduates to study a range of neurobiological processes. While immortalized or cancer cell lines offer a level of convenience for undergraduate research, particularly for larger scale course-based undergraduate research experiences (CUREs) or project-based learning (PBL), primary cell cultures more closely retain the characteristics of the tissue of origin, allowing students to engage in a wider range of authentic research projects. Astrocytes have gained increasing attention for their role in modulating neuronal viability and are at the forefront of neuroprotection research.

Spatial, temporal, and quantitative manipulation of intracellular hydrogen peroxide in cultured cells.

Hydrogen peroxide (H2O2) is produced endogenously in a number of cellular compartments, including the mitochondria, the endoplasmic reticulum, peroxisomes, and at the plasma membrane, and can play divergent roles as a second messenger or a pathological toxin. It is assumed that the tuned production of H2O2 within neuronal and nonneuronal cells regulates a discreet balance between survival and death. However, a major challenge in understanding the physiological versus pathological role of H2O2 in cells has been the lack of validated methods that can spatially, temporally, and quantitatively modulate H2O2 production.

Recent advances in hydrogen peroxide imaging for biological applications.

Mounting evidence supports the role of hydrogen peroxide (H2O2) in physiological signaling as well as pathological conditions. However, the subtleties of peroxide-mediated signaling are not well understood, in part because the generation, degradation, and diffusion of H2O2 are highly volatile within different cellular compartments. Therefore, the direct measurement of H2O2 in living specimens is critically important.

Two-photon fluorescence imaging of intracellular hydrogen peroxide with chemoselective fluorescent probes.

We present the application of two-photon fluorescence (TPF) imaging to monitor intracellular hydrogen peroxide (H₂O₂) production in brain cells. For selective imaging of H₂O₂ over other reactive oxygen species, we employed small-molecule fluorescent probes that utilize a chemoselective boronate deprotection mechanism. Peroxyfluor-6 acetoxymethyl ester detects global cellular H₂O₂ and mitochondria peroxy yellow 1 detects mitochondrial H₂O₂.

15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) protects neurons from oxidative death via an Nrf2 astrocyte-specific mechanism independent of PPARγ.

Astrocytes are critical for the antioxidant support of neurons. Recently, we demonstrated that low level hydrogen peroxide (H(2) O(2) ) facilitates astrocyte-dependent neuroprotection independent of the antioxidant transcription factor Nrf2, leaving the identity of the endogenous astrocytic Nrf2 activator to question. In this study, we show that an endogenous electrophile, 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), non-cell autonomously protects neurons from death induced by depletion of the major antioxidant glutathione.

CD36 is involved in astrocyte activation and astroglial scar formation.

Inflammation is an essential component for glial scar formation. However, the upstream mediator(s) that triggers the process has not been identified. Previously, we showed that the expression of CD36, an inflammatory mediator, occurs in a subset of astcotyes in the peri-infarct area where the glial scar forms.

Development of Neh2-luciferase reporter and its application for high throughput screening and real-time monitoring of Nrf2 activators.

The NF-E2-related factor 2 (Nrf2) is a key transcriptional regulator of antioxidant defense and detoxification. To directly monitor stabilization of Nrf2, we fused its Neh2 domain, responsible for the interaction with its nucleocytoplasmic regulator, Keap1, to firefly luciferase (Neh2-luciferase). We show that Neh2 domain is sufficient for recognition, ubiquitination, and proteasomal degradation of Neh2-luciferase fusion protein.

Hypo-osmotic swelling modifies glutamate-glutamine cycle in the cerebral cortex and in astrocyte cultures.

In our previous work, we found that perfusion of the rat cerebral cortex with hypo-osmotic medium triggers massive release of the excitatory amino acid L-glutamate but decreases extracellular levels of L-glutamine (R. E. Haskew-Layton et al.

Controlled enzymatic production of astrocytic hydrogen peroxide protects neurons from oxidative stress via an Nrf2-independent pathway.

Neurons rely on their metabolic coupling with astrocytes to combat oxidative stress. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) appears important for astrocyte-dependent neuroprotection from oxidative insults. Indeed, Nrf2 activators are effective in stroke, Parkinson disease, and Huntington disease models.

Two distinct modes of hypoosmotic medium-induced release of excitatory amino acids and taurine in the rat brain in vivo.

A variety of physiological and pathological factors induce cellular swelling in the brain. Changes in cell volume activate several types of ion channels, which mediate the release of inorganic and organic osmolytes and allow for compensatory cell volume decrease. Volume-regulated anion channels (VRAC) are thought to be responsible for the release of some of organic osmolytes, including the excitatory neurotransmitters glutamate and aspartate.

Two conventional protein kinase C isoforms, alpha and beta I, are involved in the ATP-induced activation of volume-regulated anion channel and glutamate release in cultured astrocytes.

Volume-regulated anion channels (VRACs) are activated by cell swelling and are permeable to inorganic and small organic anions, including the excitatory amino acids glutamate and aspartate. In astrocytes, ATP potently enhances VRAC activity and glutamate release via a P2Y receptor-dependent mechanism. Our previous pharmacological study identified protein kinase C (PKC) as a major signaling enzyme in VRAC regulation by ATP.

Hydrogen peroxide potentiates volume-sensitive excitatory amino acid release via a mechanism involving Ca2+/calmodulin-dependent protein kinase II.

Excessive excitatory amino acid (EAA) release in cerebral ischemia is a major mechanism responsible for neuronal damage and death. A substantial fraction of ischemic EAA release occurs via volume-regulated anion channels (VRACs). Hydrogen peroxide (H2O2), which is abundantly produced during ischemia and reperfusion, activates a number of protein kinases critical for VRAC functioning and has recently been reported to activate VRACs.