TNFα Induces DNA and Histone Hypomethylation and Pulmonary Artery Smooth Muscle Cell Proliferation Partly via Excessive Superoxide Formation

Objective: The level of tumor necrosis factor-α (TNF-α) is upregulated during the development of pulmonary vascular remodeling and pulmonary hypertension. A hallmark of pulmonary arterial (PA) remodeling is the excessive proliferation of PA smooth muscle cells (PASMCs). The purpose of this study is to investigate whether TNF-α induces PASMC proliferation and explore the potential mechanisms. Methods: PASMCs were isolated from 8-week-old male Sprague-Dawley rats and treated with 0, 20, or 200 ng/mL TNF-α for 24 or 48 h. After treatment, cell number, superoxide production, histone acetylation, DNA methylation, and histone methylation were assessed. Results: TNF-α treatment increased NADPH oxidase activity, superoxide production, and cell numbers compared to untreated controls. TNF-α-induced PASMC proliferation was rescued by a superoxide dismutase mimetic tempol. TNF-α treatment did not affect histone acetylation at either dose but did significantly decrease DNA methylation. DNA methyltransferase 1 activity was unchanged by TNF-α treatment. Further investigation using QRT-RT-PCR revealed that GADD45-α, a potential mediator of DNA demethylation, was increased after TNF-α treatment. RNAi inhibition of GADD45-α alone increased DNA methylation. TNF-α impaired the epigenetic mechanism leading to DNA hypomethylation, which can be abolished by a superoxide scavenger tempol. TNF-α treatment also decreased H3-K4 methylation. TNF-α-induced PASMC proliferation may involve the H3-K4 demethylase enzyme, lysine-specific demethylase 1 (LSD1). Conclusions: TNF-α-induced PASMC proliferation may be partly associated with excessive superoxide formation and histone and DNA methylation

Abstract 508: TNFα Downregulates DNA Methylation and Increases Pulmonary Arterial Smooth Muscle Cell (PASMC) Proliferation

Background: Chronic cold exposure triggers robust TNFα production in the lungs and pulmonary arteries (PAs) and causes PA remodeling in rats. A hallmark of the PA remodeling is the over-proliferation of PASMCs. The purpose of this experiment was to investigate potential mechanisms of TNF-alpha induced PASMC proliferation. Methods and Results: PASMCs were isolated from 8-week-old male Sprague Dawley rats and treated with 0, 20 or 200 ng/ml TNFα for 24 or 48 hours. After treatment, cell number, superoxide production, histone acetylation and DNA methylation were assessed. TNFα treatment significantly increased the number of PASMCs, indicating excessive proliferation. TNFα also increased NADPH oxidase activity and superoxide production compared with untreated controls. TNFα treatment however did not affect histone acetylation at either dose. Interestingly, DNA methylation was significantly decreased by TNFα treatment compared to controls. Unexpectedly, the activity of DNA methyltransferase-1, the major enzyme for DNA methylation, was not altered by TNFα treatment. Further investigation using QRT-RT-PCR revealed that TNFα upregulated several factors including Gadd45α that regulate DNA de-methylation. Conclusions: Our results show that TNFα treatment induced cell proliferation and increased superoxide production in PASMCs. TNFα decreased DNA methylation and upregulated mediators of de-methylation in PASMCs. These findings suggest that TNF-alpha induced PASMCs proliferation may involve the DNA methylation mechanism. (Supported by NIH HL077490 and AHA 11PRE7830040). </jats:p

Physiology core concepts in the classroom: reflections from faculty

It is increasingly difficult for faculty to cover all of the content in a physiology course. Given this constraint, recent efforts in the physiology teaching community, and in particular the Physiology Majors Interest Group (P-MIG), have promoted using core concepts to help students master key physiological principles. This report summarizes the experiences of four faculty members who teach physiology using the core concepts in various educational environments and identifies several common strengths and challenges they have encountered thus far. Strengths of using the core concepts include the transfer of knowledge to solve unknown problems and providing a framework to build a course. Challenges include applying them in a teach-taught course and balancing time spent on content and the core concepts. This is the first report to document the use of the physiology core concepts in a course, and the authors encourage additional faculty to not only adopt the core concepts for their own use, but share their approaches and experiences with the entire teaching community. </jats:p

Advising physiology students: perceptions from the programs

Academic advising outcomes can be linked to both student success and retention. Yet relatively little is known specifically related to advising in physiology programs. Professional organizations dedicated to academic advising in general, and more specifically advising future health professional students exist, yet, whether current physiology programs utilize these resources remains unknown, as does a number of other demographic information about advising in physiology programs. Here we present data gathered from a sample of physiology educators to inform what current advising practices of physiology students are. Forty-five respondents from a variety of institutions and programs provided information on advising structures, resources utilized, student populations, and concerns. While programs may differ, many of the concerns regarding advising physiology students are the same. </jats:p

Advising Physiology Students: Perceptions from the Programs

Academic advising outcomes can be linked to both student success and retention. Yet relatively little is known specifically related to advising in physiology programs. Pro- fessional organizations dedicated to academic advising in general, and more specifically advising future health professional students exist, yet, whether current physiology programs utilize these resources remains unknown, as does a number of other demographic informa- tion about advising in physiology programs. Here we present data gathered from a sample of physiology educators to inform what current advising practices of physiology students are. Forty-five re- spondents from a variety of institutions and programs provided information on advising structures, resources utilized, student popu- lations, and concerns. While programs may differ, many of the concerns regarding advising physiology students are the same

The 2019 P-MIG Student Survey Report and Capturing the Undergraduate Perspective of Physiology Programming

The aim of the 2019 Student Survey was to inform the Physiology Majors Interest Group (PMIG) of characteristics of undergraduates enrolled in physiology courses or degree programs from across the United States, to be used as one input source for development of program-level guidelines. 1389 participants from seven universities completed the 2019 P-MIG Student Survey. 37% reported enrollment in a physiology/human physiology major; allied health related programs were the second most common (24%). 61% of respondents reported attending a community college, the majority of whom enrolled in one or more courses at a community college while in high school (44%). Of participants who reported transferring coursework from one institution to another, 72% reported coursework transferred as expected. Homeostasis and Structure/Function were the two core concepts common to the top rankings for self-reported mastery, the expectation to be remembered in five years, and deemed to be career-relevant. Survey respondents indicated high engagement in co-curricular activities, with 72% participating or planning to participate in job shadowing opportunities followed by volunteering (57%) and internships (50%). Over half of all survey participants indicated they “strongly agree” that their coursework and undergraduate programming has prepared them for success in their field of study. While the majority of respondents were satisfied with the academic advising received, additional guidance with regard to career choices and non-coursework professional development opportunities may be beneficial. Taken together, the collective data provides information from current physiology students that may inform development of consensus guidelines regarding curriculum, professional skills, and advising for undergraduate physiology degree programs