Teaching Gradually Armstrong, Kacie L; Genova, Lauren A; Greenlee, John Wyatt ...
Stylus Publishing LLC,
2021, 2021-09-27, 2023-07-03
eBook, Book
This book covers a wide range of topics designed to appeal to graduate student instructors across disciplines, from those teaching discussion sections, to those managing studio classes and lab ...sessions, to those serving as the instructor of record for their own course.
It is well established that mitogens inhibit differentiation of skeletal muscle cells, but the insulin-like growth factors (IGFs), acting through a single receptor, stimulate both proliferation and ...differentiation of myoblasts. Although the IGF-I mitogenic signaling pathway has been extensively studied in other cell types, little is known about the signaling pathway leading to differentiation in skeletal muscle. By using specific inhibitors of the IGF signal transduction pathway, we have begun to define the signaling intermediates mediating the two responses to IGFs. We found that PD098059, an inhibitor of mitogen-activated protein (MAP) kinase kinase activation, inhibited IGF-stimulated proliferation of L6A1 myoblasts and the events associated with it, such as phosphorylation of the MAP kinases and elevation of c-fos mRNA and cyclin D protein. Surprisingly, PD098059 caused a dramatic enhancement of differentiation, evident both at a morphological (fusion of myoblasts into myotubes) and biochemical level (elevation of myogenin and p21 cyclin-dependent kinase inhibitor expression, as well as creatine kinase activity). In sharp contrast, LY294002, an inhibitor of phosphatidylinositol 3-kinase, and rapamycin, an inhibitor of the activation of p70 S6 kinase (p70S6k), completely abolished IGF stimulation of L6A1 differentiation. We found that p70S6k activity increased substantially during differentiation, and this increase was further enhanced by PD098059. Our results demonstrate that the MAP kinase pathway plays a primary role in the mitogenic response and is inhibitory to the myogenic response in L6A1 myoblasts, while activation of the phosphatidylinositol 3-kinase/p70S6k pathway is essential for IGF-stimulated differentiation. Thus, it appears that signaling from the IGF-I receptor utilizes two distinct pathways leading either to proliferation or differentiation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Teaching Gradually is a guide for anyone new to teaching and learning in higher education. Written for graduate student instructors, by graduate students with substantive teaching experience, this ...resource is among the first of its kind to speak to graduate students as comrades-in-arms with voices from alongside them in the trenches, rather than from far behind the lines. Each author featured in this book was a graduate student at the time they wrote their contribution. Consequently, the following chapters give scope to a newer, diverse generation of educators who are closer in experience and professional age to the book's intended audience. The tools, methods, and ideas discussed here are ones that the authors have found most useful in teaching today's students. Each chapter offers a variety of strategies for successful classroom practices that are often not explicitly covered in graduate training.
Overall, this book consists of 42 chapters written by 51 authors who speak from a vast array of backgrounds and viewpoints, and who represent a broad spectrum of experience spanning small, large, public, and private institutions of higher education. Each chapter offers targeted advice that speaks to the learning curve inherent to early-career teaching, while presenting tangible strategies that readers can leverage to address the dynamic professional landscape they inhabit. The contributors' stories and reflections provide the context to build the reader's confidence in trying new approaches in their his or her teaching. This book covers a wide range of topics designed to appeal to graduate student instructors across disciplines, from those teaching discussion sections, to those managing studio classes and lab sessions, to those serving as the instructor of record for their own course. Despite the medley of content, two common threads run throughout this volume: a strong focus on diversity and inclusion, and an acknowledgment of the increasing shift to online teaching.A
It has long been known that nerves stimulate growth and maintenance of skeletal muscles in ways not dependent on physical
contacts, but numerous attempts to identify and characterize the myotrophic ...agent(s) secreted by nerves have been unsuccessful.
We here suggest that products of the neuregulin gene may be these agents. The neuregulins are a family of proteins made by
alternative splicing of a single transcript to give as many as 15 protein products. One member of this family, glial growth
factor 2 (rhGGF2) is a very potent stimulator of myogenesis in L6A1 myoblasts, giving a maximal stimulation of cell fusion
and creatine kinase elevation at a concentration of 1 ng/ml (18 p M ). The stimulation of myogenesis is not rapid, but it is prolonged, continuing over a period of at least 6 days. The effects
of rhGGF2 are additive with those of insulin-like growth factor I (IGF-I) or its analog R3-IGF-I, suggesting that the actions
of these two myotrophic agents differ in at least one rate-limiting step. We have observed one possible difference; unlike
the IGFs, rhGGF2 does not induce elevation of the steady state level of myogenin mRNA.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Multiple mitochondrial ATPase inhibitor genes have been identified in the rat-genome. The sequences of two genomic clones indicate that one encodes the functional gene, and the other is a processed ...pseudogene. The ATPase inhibitor gene isolated is about 1.5 kb long and the coding region contains three exons and two introns. The presence of multiple pseudogenes in the rat is suggested by this study and this is unique since in the bovine genome only a single gene has been found, which is also confirmed here. The presence of multiple inhibitor transcripts in the rat suggests that the functional gene might have multiple transcriptional start sites.
It has long been known that nerves stimulate growth and maintenance of skeletal muscles in ways not dependent on physical contacts, but numerous attempts to identify and characterize the myotrophic ...agent(s) secreted by nerves have been unsuccessful. We here suggest that products of the neuregulin gene may be these agents. The neuregulins are a family of proteins made by alternative splicing of a single transcript to give as many as 15 protein products. One member of this family, glial growth factor 2 (rhGGF2) is a very potent stimulator of myogenesis in L6A1 myoblasts, giving a maximal stimulation of cell fusion and creatine kinase elevation at a concentration of 1 ng/ml (18 pM). The stimulation of myogenesis is not rapid, but it is prolonged, continuing over a period of at least 6 days. The effects of rhGGF2 are additive with those of insulin-like growth factor I (IGF-I) or its analog R3-IGF-I, suggesting that the actions of these two myotrophic agents differ in at least one rate-limiting step. We have observed one possible difference; unlike the IGFs, rhGGF2 does not induce elevation of the steady state level of myogenin mRNA.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Introduction Armstrong, Kacie L.; Genova, Lauren A.; Greenlee, John Wyatt ...
Teaching Gradually,
2021
Book Chapter
Teaching is a craft that one never truly perfects. Effective teaching does not always come naturally, and for this reason, many educators seek some degree of pedagogical training throughout their ...careers. It is worth noting, however, that such training is often delivered by seasoned professionals whose vast experience and accomplishments can distance them from the immediate needs of graduate student instructors. This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book offers targeted advice that speaks to the learning curve inherent to early career teaching, while presenting tangible strategies that readers can leverage to navigate the dynamic professional landscape they inhabit. It encounters a series of engaging stories, anecdotes, and reflections that will help clarify our path forward and inspire us to try new skills in the experimental setting that is the college classroom.
Our previous work has demonstrated that the insulin-like growth factors (IGFs), acting through a single receptor, stimulate both proliferation and differentiation of L6A1 myoblasts. This unique model ...system has enabled us to closely examine the switch that regulates these two opposing responses. We have previously shown, using specific inhibitors of the IGF-I signal transduction pathway, that the mitogenic response is mediated by the Ras/Raf/MAP kinase pathway and the myogenic response by the PI 3-kinase/p70s6k pathway (Coolican SA, Samuel DS, Ewton DZ, McWade FJ, Florini JR, J Biol Chem 1997; 272: 6653-62). In that study we found that PD098059, an inhibitor of MEK activation, inhibited the proliferative response, but dramatically enhanced IGF-stimulated differentiation which was associated with elevation of p70s6k activity. Since there have been reports of elevation of Raf-1 activity in PD098059-treated L6 myoblasts, and stimulation of p70s6k activity in cells expressing an activated Raf-1, it was important to determine whether or not Raf-1 elevation plays a role in the myogenic response. To test this, we have transfected L6A1 myoblasts with delta Raf-1:ER, an estradiol-regulated form of oncogenic Raf-1. We found that activation of Raf-1 by estradiol resulted in increased phosphorylation of p42 and p44 MAP kinases and stimulation of proliferation. In contrast, Raf-1 activation inhibited all measured aspects of the myogenic response: myogenin expression, creatine kinase elevation, and fusion of myoblasts to form myotubes. In addition, we found no elevation of p70s6k activity upon Raf-1 activation. These results indicate the following: (1) stimulation of myogenic differentiation by PD098059 treatment is not simply due to the elevation of Raf-1, (2) Raf-1 has a positive role in the MAP kinase pathway and myoblast proliferation, and (3) Raf-1 activation inhibits myogenesis, possibly by forcing cells to remain in the proliferative state.
Multiple mitochondrial ATPase inhibitor genes have been identified in the rat genome. The sequences of two genomic clones indicate that one encodes the functional gene, and the other is a processed ...pseudogene. The ATPase inhibitor gene isolated is about 1.5 kb long and the coding region contains three exons and two introns. The presence of multiple pseudogenes in the rat is suggested by this study and this is unique since in the bovine genome only a single gene has been found, which is also confirmed here. The presence of multiple inhibitor transcripts in the rat suggests that the functional gene might have multiple transcriptional start sites.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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