Using cognitive load theory to evaluate and improve preparatory materials and study time for the flipped classroom.

BACKGROUND: Preclinical medical education is content-dense and time-constrained. Flipped classroom approaches promote durable learning, but challenges with unsatisfactory student preparation and high workload remain. Cognitive load theory defines instructional design as "efficient" if learners can master the presented concepts without cognitive overload. We created a PReparatory Evaluation Process (PREP) to systematically assess and measure improvement in the cognitive-load efficiency of preparatory materials and impact on study time (time-efficiency). METHODS: We conducted this study in a flipped, multidisciplinary course for ~ 170 first year students at Harvard Medical School using a naturalistic post-test design. For each flipped session (n = 97), we assessed cognitive load and preparatory study time by administering a 3-item PREP survey embedded within a short subject-matter quiz students completed before class. Over three years (2017-2019), we evaluated cognitive load- and time- based efficiency to guide iterative revisions of the materials by content experts. The ability of PREP to detect changes to the instructional design (sensitivity) was validated through a manual audit of the materials. RESULTS: The average survey response rate was ≥ 94%. Content expertise was not required to interpret PREP data. Initially students did not necessarily allocate the most study time to the most difficult content. Over time, the iterative changes in instructional design increased the cognitive load- and time-based efficiency of preparatory materials with large effect sizes (p < .01). Furthermore, this increased the overall alignment of cognitive load with study time: students allocated more time to difficult content away from more familiar, less difficult content without increasing workload overall. CONCLUSIONS: Cognitive load and time constraints are important parameters to consider when designing curricula. The PREP process is learner-centered, grounded in educational theory, and works independently of content knowledge. It can provide rich and actionable insights into instructional design of flipped classes not captured by traditional satisfaction-based evaluations.

A hierarchy of needs for remote undergraduate medical education: lessons from the medical student experience.

PURPOSE: The disruption of undergraduate medical education (UME) by the COVID-19 pandemic has sparked rapid, real-time adjustments by medical educators and students. While much is known about online teaching in general, little guidance is available to medical educators on how to adapt courses not originally designed for the online environment. To guide our faculty in this transition we conducted a needs assessment of students enrolled in virtual courses across all 4 years of UME training. METHODS: Using a mixed-methods approach, we conducted a single-institution virtual learning needs assessment in May and June of 2020. We developed and disseminated a survey to assess student experiences with virtual learning. We conducted quantitative and qualitative analysis of responses (n = 255 or 39%) to identify emergent themes. RESULTS: We identified six interdependent themes that need to be met for medical students to fully reach their learning potential: access to stable internet and quiet study spaces, flexible course design with asynchronous, self-paced components, clear expectations for engagement with content and each other, a sense of connectedness with faculty and peers, synchronous classes that maximize interactivity, and assessments that foster a sense of learning over performance. Interpersonal relationships with faculty and peers affected students' sense of learning more than any other factor. CONCLUSIONS: Based on our findings we propose a hierarchy of needs for virtual learning that provides guidance on adapting existing medical school courses to the remote setting and overcoming common challenges. We highlight opportunities for how virtual elements may enrich in-person courses going forward, including in the clinical setting. Although the solutions required to meet the threshold of need at each level may differ based on the context, attending to these same fundamental needs can be extrapolated and applied to learners across a range of environments beyond the virtual.

Advanced Integrated Science Courses: Building a Skill Set to Engage With the Interface of Research and Medicine.

Scientific research has been changing medical practice at an increasing pace. To keep up with this change, physicians of the future will need to be lifelong learners with the skills to engage with emerging science and translate it into clinical care. How medical schools can best prepare students for ongoing scientific change remains unclear. Adding to the challenge is reduced time allocated to basic science in curricula and rapid expansion of relevant scientific fields. A return to science with greater depth after clinical clerkships has been suggested, although few schools have adopted such curricula and implementation can present challenges. The authors describe an innovation at Harvard Medical School, the Advanced Integrated Science Courses (AISCs), which are taken after core clerkships. Students are required to take 2 such courses, which are offered in a variety of topics. Rather than factual content, the learning objectives are a set of generalizable skills to enable students to critically evaluate emerging research and its relationship to medical practice. Making these generalizable skills the defining principle of the courses has several important advantages: it allows standardization of acquired skills to be combined with diverse course topics ranging from basic to translational and population sciences; students can choose courses and projects aligned with their interests, thereby enhancing engagement, curiosity, and career relevance; schools can tailor course offerings to the interests of local faculty; and the generalizable skills delineate a unique purpose of these courses within the overall medical school curriculum. For the 3 years AISCs have been offered, students rated the courses highly and reported learning the intended skill set effectively. The AISC concept addresses the challenge of preparing students for this era of rapidly expanding science and should be readily adaptable to other medical schools.

The Harvard Medical School Pathways Curriculum: Reimagining Developmentally Appropriate Medical Education for Contemporary Learners.

As the U.S. health care system changes and technology alters how doctors work and learn, medical schools and their faculty are compelled to modify their curricula and teaching methods. In this article, educational leaders and key faculty describe how the Pathways curriculum was conceived, designed, and implemented at Harvard Medical School. Faculty were committed to the principle that educators should focus on how students learn and their ability to apply what they learn in the evaluation and care of patients. Using the best evidence from the cognitive sciences about adult learning, they made major changes in the pedagogical approach employed in the classroom and clinic. The curriculum was built upon 4 foundational principles: to enhance critical thinking and provide developmentally appropriate content; to ensure both horizontal integration between courses and vertical integration between phases of the curriculum; to engage learners, foster curiosity, and reinforce the importance of student ownership and responsibility for their learning; and to support students' transformation to a professional dedicated to the care of their patients and to their obligations for lifelong, self-directed learning.The practice of medicine is rapidly evolving and will undoubtedly change in multiple ways over the career of a physician. By emphasizing personal responsibility, professionalism, and thinking skills over content transfer, the authors believe this curriculum will prepare students not only for the first day of practice but also for an uncertain future in the biological sciences, health and disease, and the nation's health care system, which they will encounter in the decades to come.

Autoubiquitination of the 26S proteasome on Rpn13 regulates breakdown of ubiquitin conjugates.

Degradation rates of most proteins in eukaryotic cells are determined by their rates of ubiquitination. However, possible regulation of the proteasome's capacity to degrade ubiquitinated proteins has received little attention, although proteasome inhibitors are widely used in research and cancer treatment. We show here that mammalian 26S proteasomes have five associated ubiquitin ligases and that multiple proteasome subunits are ubiquitinated in cells, especially the ubiquitin receptor subunit, Rpn13. When proteolysis is even partially inhibited in cells or purified 26S proteasomes with various inhibitors, Rpn13 becomes extensively and selectively poly-ubiquitinated by the proteasome-associated ubiquitin ligase, Ube3c/Hul5. This modification also occurs in cells during heat-shock or arsenite treatment, when poly-ubiquitinated proteins accumulate. Rpn13 ubiquitination strongly decreases the proteasome's ability to bind and degrade ubiquitin-conjugated proteins, but not its activity against peptide substrates. This autoinhibitory mechanism presumably evolved to prevent binding of ubiquitin conjugates to defective or stalled proteasomes, but this modification may also be useful as a biomarker indicating the presence of proteotoxic stress and reduced proteasomal capacity in cells or patients.

Cancer vulnerabilities unveiled by genomic loss.

Due to genome instability, most cancers exhibit loss of regions containing tumor suppressor genes and collateral loss of other genes. To identify cancer-specific vulnerabilities that are the result of copy number losses, we performed integrated analyses of genome-wide copy number and RNAi profiles and identified 56 genes for which gene suppression specifically inhibited the proliferation of cells harboring partial copy number loss of that gene. These CYCLOPS (copy number alterations yielding cancer liabilities owing to partial loss) genes are enriched for spliceosome, proteasome, and ribosome components. One CYCLOPS gene, PSMC2, encodes an essential member of the 19S proteasome. Normal cells express excess PSMC2, which resides in a complex with PSMC1, PSMD2, and PSMD5 and acts as a reservoir protecting cells from PSMC2 suppression. Cells harboring partial PSMC2 copy number loss lack this complex and die after PSMC2 suppression. These observations define a distinct class of cancer-specific liabilities resulting from genome instability.

Affinity purification of mammalian 26S proteasomes using an ubiquitin-like domain.

The standard methods for the isolation of the 26S proteasomes from mammalian tissues have long involved multiple chromatographic steps. This process led to loss of loosely associated regulatory proteins or cofactors and yielded particles with low functional capacity. Here, we describe a single-step affinity purification of 26S proteasome complexes that preserves the association with many 26S proteasome-interacting proteins. Our approach uses the ubiquitin-like domain of human RAD23B as an affinity bait, which allows the rapid and gentle isolation of 26S proteasomes with high purity. This strategy does not require the genetic introduction of tagged subunits nor expensive antibodies, and therefore can be used to isolate 26S proteasomes from any mammalian tissue or yeast. This method, therefore, is an important new tool to study 26S proteasome function in various models of human diseases that are linked to changes in the ubiquitin proteasome system, for example the increased proteasomal proteolysis seen in muscle wasting or the decreased proteasomal capacity that has been reported in various neurodegenerative diseases.

Muscle wasting in aged, sarcopenic rats is associated with enhanced activity of the ubiquitin proteasome pathway.

Among the hallmarks of aged organisms are an accumulation of misfolded proteins and a reduction in skeletal muscle mass ("sarcopenia"). We have examined the effects of aging and dietary restriction (which retards many age-related changes) on components of the ubiquitin proteasome system (UPS) in muscle. The hindlimb muscles of aged (30 months old) rats showed a marked loss of muscle mass and contained 2-3-fold higher levels of 26S proteasomes than those of adult (4 months old) controls. 26S proteasomes purified from muscles of aged and adult rats showed a similar capacity to degrade peptides, proteins, and an ubiquitylated substrate, but differed in levels of proteasome-associated proteins (e.g. the ubiquitin ligase E6AP and deubiquitylating enzyme USP14). Also, the activities of many other deubiquitylating enzymes were greatly enhanced in the aged muscles. Nevertheless, their content of polyubiquitylated proteins was higher than in adult animals. The aged muscles contained higher levels of the ubiquitin ligase CHIP, involved in eliminating misfolded proteins, and MuRF1, which ubiquitylates myofibrillar proteins. These muscles differed from ones rapidly atrophying due to disease, fasting, or disuse in that Atrogin-1/MAFbx expression was low and not inducible by glucocorticoids. Thus, the muscles of aged rats showed many adaptations indicating enhanced proteolysis by the UPS, which may enhance their capacity to eliminate misfolded proteins and seems to contribute to the sarcopenia. Accordingly, dietary restriction decreased or prevented the aging-associated increases in proteasomes and other UPS components and reduced muscle wasting.

Ubiquitinated proteins activate the proteasome by binding to Usp14/Ubp6, which causes 20S gate opening.

In eukaryotic cells, ubiquitination of proteins leads to their degradation by the 26S proteasome. We tested if the ubiquitin (Ub) chain also regulates the proteasome's capacity for proteolysis. After incubation with polyubiquitinated proteins, 26S proteasomes hydrolyzed peptides and proteins 2- to 7-fold faster. Ub conjugates enhanced peptide hydrolysis by stimulating gate opening in the 20S proteasome. This stimulation was seen when this gate was closed or transiently open, but not maximally open. Gate opening requires conjugate association with Usp14/Ubp6 and also occurs if Ub aldehyde occupies this isopeptidase's active site. No stimulation was observed with 26S from Ubp6Delta mutants, but this effect was restored upon addition of Usp14/Ubp6 (even an inactive Ubp6). The stimulation of gate opening by Ub conjugates through Usp14/Ubp6 requires nucleotide binding to the gate-regulatory ATPases. This activation enhances the selectivity of the 26S proteasome for ubiquitinated proteins and links their deubiquitination to their degradation.

Getting to first base in proteasome assembly.

Assembly of complex structures such as the eukaryotic 26S proteasome requires intricate mechanisms that ensure precise subunit arrangements. Recent studies have shed light on the pathway for ordered assembly of the base of the 19S regulatory particle of the 26S proteasome by identifying new precursor complexes and four dedicated chaperones involved in its assembly.

Isolation of mammalian 26S proteasomes and p97/VCP complexes using the ubiquitin-like domain from HHR23B reveals novel proteasome-associated proteins.

Recent studies, mainly in yeast, have identified various cofactors that associate with the 26S proteasome and appear to influence its function. To identify these proteins in different cells and physiological states, we developed a method to gently and rapidly isolate 26S proteasomes and associated proteins without the need for genetic modifications of the proteasome. This method is based on the affinity of this complex for the ubiquitin-like (UBL) domain of hHR23B and elution with a competing polypeptide containing a ubiquitin-interacting motif. Associated with 26S proteasomes from rat muscle were a variety of known proteasome-interacting proteins, activators, and ubiquitin conjugates. In addition, we identified over 40 proteins not previously known to associate with the 26S proteasome, some of which were tightly associated with the proteasome in a substoichiometric fashion, e.g., the deubiquitinating enzymes USP5/isopeptidase T and USP7/HAUSP and the ubiquitin ligases ARF-BP1/HUWE1 and p600/UBR4. By altering buffer conditions, we also purified by this approach complexes of the ATPase p97/VCP associated with its adaptor proteins Ufd1-Npl4, p47, SAKS1, and FAF1, all of which contain ubiquitin-binding motifs. These complexes were isolated with ubiquitin conjugates bound and were not previously known to bind to the UBL domain of hHR23B. These various UBL-interacting proteins, dubbed the UBL interactome, represent a network of proteins that function together in ubiquitin-dependent proteolysis, and the UBL method offers many advantages for studies of the diversity, functions, and regulation of 26S proteasomes and p97 complexes under different conditions.