bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel cholesterol‐dependent regulation of cardioprotective KATP subunit expression in HL‐1 cardiomyocytes
Authors: Geiger Robert , Fatima Naheed , Flagg Thomas
Published: June 2021

Hypercholesterolemia is associated with poor cardiovascular health. In a recent study, we discovered that histone deacetylase inhibitors (HDIs) cause a significant depletion of cholesterol in HL‐1 cardiomyocytes that is associated with increased expression of the sulfonylurea receptor subunit (SUR2/ABCC9) of the ATP‐sensitive potassium (KATP) channel. This implies that cellular cholesterol levels modulate the number of KATP, which play a key role in protecting the heart from damage during stress. The mechanism by which cholesterol modulates SUR2 expression is unknown. Analysis of the sequence upstream of the SUR2 gene revealed binding sites for the cholesterol‐sensitive transcription factor, SREBP (Sterol Response Element Binding Protein), in the SUR2 promoter. Therefore, we tested the hypothesis that HDI‐dependent cholesterol depletion increases SUR2 by activating SREBP. As expected, treatment of HL‐1 cardiomyocytes with canonical HDI, trichostatin A (TSA; 30 ng/mL) for 72 hours caused a marked increase (20‐fold) of SUR2 mRNA expression compared to control. In addition, we observe increased activation of SREBP and marked increases in expression of selected SREBP‐target genes, including SCAP, IDOL, and PCSK9. Finally, in luciferase promoter assays, SREBP markedly increases reporter gene expression driven by the upstream SUR2 promoter (−510/−40) sequence, which contains a putative SREBP binding site. Taken together, our findings demonstrate a cholesterol‐dependent mechanism regulating expression of the cardioprotective KATP channel and suggest a novel mechanism by which hypercholesterolemia may promote poor cardiovascular health.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Dysfunction of Acid‐Sensing Ion Channel 5 (ASIC5) in Unipolar Brush Cells of the Vestibulocerebellum Causes Ataxia
Authors: Boiko Nina , Kucher Volodymyr , Stockand James D.
Published: June 2021

Acid‐sensing ion channels (ASICs) are ligand‐gated ion channels in the Degenerin/Epithelial Na+ channel (Deg/ENaC) family. ASIC proteins are richly expressed in mammalian neurons. Mammals express five ASIC genes: ASIC1‐5. The gene product of ASIC5 is an orphan member of the family about which little is known. To assess the function of ASIC5, we created ASIC5 reporter and knockout mice. We find that ASIC5 is chiefly expressed in the brain in the cerebellum, specifically in the ventral uvula and nodulus of the vestibulocerebellum. Here, ASIC5 is restrictively expressed in a subset of interneurons in the granular layer. The locale, distinctive shape and immunohistochemical properties of these ASIC5‐expressing interneurons identify them as unipolar brush cells (UBC). ASIC5 is richly expressed in a subset of UBCs that also express the metabotropic glutamate receptor 1α (mGluR1α). Such observations are consistent with ASIC5 playing a key role in the physiology of UBCs and in the function of the vestibulocerebellum, which is essential for normal balance and movement. Consistent with this, knockout of ASIC5 results in ataxia and uncoordinated bodily movements.

Support or Funding Information

This work was funded by a CPRIT IIRG grant (RP150408) and a NIH/NCI R21 grant (CA194138)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Mechanistic Study of Four Co‐Morbid Hyperlipidemia‐Related Pathologies Reveals NFκB and STAT3‐Mediated miR‐155 and miR‐221 Potentially Serve as Master Regulators, and Elucidates Metabolically Healthy Obese Model
Authors: Johnson Candice , Drummer Charles , Virtue Anthony , Gao Tracy , Hernandez Miguel , Singh Lexy , Wang Hong , Yang Xiao‐Feng
Published: June 2021

Hyperlipidemia afflicts more than 70 million Americans and is commonly linked with atherosclerosis, obesity, non‐alcoholic fatty liver disease (NAFLD) and type II diabetes. In recent years, microRNAs (miRNAs) have been firmly established as important regulators in these hyperlipidemia‐related pathologies. However, much remains to be understood regarding miRNAs' overlap and function within these hyperlipidemia‐related pathologies. Our recent JBC paper (PMID: 27856635) has shown that miRNA‐155 is significantly increased in atherosclerosis but reduced in high‐fat diet‐induced obesity. We published the findings that global miR‐155 deficiency in an atherosclerotic mouse background yielded a novel metabolically healthy obese mouse model, which exhibits improved atherosclerosis but resulted in obesity, NAFLD, and hyperinsulinemia without insulin resistance. Such a finding implied 1) a potent role of a single miRNA to differentially affect hyperlipidemia‐related diseases such that miRNAs achieve master gene candidacy status; and 2) a differential expression of downstream targets of miRNA in different cell types. In our current study, we sought to expand our understanding of the various miRNAs in these hyperlipidemia‐related conditions, specifically in regards to their expression direction, regulation and function. We hypothesized that miRNAs function as a potent master regulator that directs pathogenesis of hyperlipidemia‐related diseases where only a few miRNAs are shared between two or more hyperlipidemia‐related conditions (e.g., atherosclerosis, obesity, insulin resistance/type II diabetes and NAFLD). Using microarray and other experimentally verified‐based datamining approaches, we found that, among nearly 150 miRNAs, miR‐155 and miR‐221 are significantly modulated in all four hyperlipidemia‐related diseases. Our results also show a significant role for NFκB and STAT3 as upstream regulators for these and other miRNAs. Our datamining results identified mRNA targets that could contribute to the disease manifestations. Additionally, we identified groups of miRNAs that are unique to one hyperlipidemia‐related disease type as well as miRNAs that were modulated in comorbidities, which may be useful as future disease biomarkers in differentiation, diagnosis and prognosis. Taken together, we are first to show that NFκB‐ and STAT3‐mediated miR‐155 and miR‐221 potentially serve as master regulators for four co‐morbid hyperlipidemia‐related diseases.

Support or Funding Information

NIH‐NHLBI

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Effects of Short Chain Fatty Acid Mixtures on Colonic Motility
Authors: Kendig Derek M. , Hurst Norman , Favreau Alexander
Published: June 2021

The effects of nutrients on a variety of colonic function has been well studied. Recent evidence has suggested that sensing of many different intraluminal nutrients (glucose, amino acids) is accomplished through plasma membrane receptors within the intestinal epithelium. These membrane receptors are often linked to hormone release from enteroendocrine cells. While many digested nutrients are present at higher intraluminal concentrations within the small intestine before they are absorbed, short chain fatty acids (SCFAs) in particular are generated by bacterial metabolism of nutrients within the colon. Based on previous studies, the most prominent individual SCFAs (butyrate, acetate, and propionate) have differential effects on cellular signaling and motility within the colon. However, the overall effects of mixtures of these SCFAs, which are more similar to intraluminal conditions, have not been elucidated. In this study, we measured colonic motility of both the proximal and distal colon in response to SCFA mixtures. Motility in the proximal colon of guinea pigs was measured as full‐propagating, shortpropagating, or non‐propagating contractions through video capture and subsequent generation of spatiotemporal maps. Motility in guinea pig distal colon was measured by velocity of fecal pellet propulsion. An 30mM SCFA mixture with a molar ratio of 3:2:1 (acetate: butyrate: propionate) increased velocity of fecal pellet propulsion. This increase in distal colonic motility was inhibited by GR113808, an antagonist of 5‐HT4 receptors, suggesting that mediation of motility effects was through serotonin. Statistical comparisons of pellet velocity were made by one‐way repeated measures ANOVA. In the proximal colon, the same SCFA mixture reduced the presence of short‐propagating contractions (<50% of the tissue length) while not affecting full‐propagating contractions. These results suggest that SCFA mixtures have differential effects on propulsive motility in the proximal and distal colon of guinea pigs. Future work will elucidate the presence of the FFAR2 and FFAR3 receptors in relation to enteroendocrine cells containing serotonin and other endocrine mediators of colonic function (peptide YY, neurotensin).

Support or Funding Information

This work was supported by a summer research grant to DMK from Loyola University Maryland and a small grant by the VCU postdoctoral association. DMK was also partially supported by an NIGMS IRACDA grant GM093857 to VCU.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of Creatine Supplementation and Doxorubicin Treatment on Diaphragm Myogenic Regulatory Factor Expression
Authors: Jones Megan , Busekrus Raquel , Torok Zoltan , Hydock David
Published: June 2021

The purpose of this study was to explore the effects of creatine monohydrate (Cr) supplementation and the chemotherapy drug doxorubicin (DOX) on myogenic regulatory factor (MRF) expression in the diaphragm. Male Sprague‐Dawley rats were fed either a diet supplemented with 3% Cr or a standard control (CON) diet for two weeks. Animals were then randomly assigned to receive 15 mg/kg of DOX or saline (SAL) as a placebo. After five days, animals were anesthetized, diaphragms were removed, and expression of the primary MRFs MyoD and Myf5 were quantified using Western blotting. When compared to CON+SAL diaphragm, MyoD expression was 24% and 31% lower in diaphragms from CON+DOX and Cr+DOX, respectively. Myf5 expression was 15% and 41% higher in diaphragm from CON+DOX and Cr+DOX, respectively, when compared to CON+SAL diaphragm. A trend toward DOX decreasing MyoD and increasing Myf5 expression in diaphragm was observed, and the trend toward Cr increasing Myf5 expression with DOX treatment warrants further investigation.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The effects of natural products from a medicinal plant (Cinnamosma fragrans) on contractions of a visceral muscle in the Zika vector Aedes aegypti
Authors: DeLaat Andrew , Rakotondraibe Harinantenaina Liva , Piermarini Peter
Published: June 2021

Mosquito‐borne diseases such as malaria, dengue fever, and Zika, are a constantly evolving problem with newly emerging and reemerging pathogens threatening the health of millions of individuals worldwide. Prevention of these diseases relies on the effective control of mosquito populations with insecticides. Our group is developing new insecticides derived from natural products of the Madagascan medicinal plant Cinnamosma fragrans by understanding the interactions of these compounds with mosquitoes on a molecular and physiological level and how they exert their toxic effects. The goal of this study is to determine the effects of natural drimane sesquiterpene compounds isolated from the medicinal plant C. fragrans on the visceral muscle contractions of the ventral diverticulum (crop) in adult female yellow fever mosquitoes (Aedes aegypti), an important vector of Zika virus. Using an established bioassay, we evaluated the acute effects of several drimane sesquiterpenes on contraction rates of isolated crops in Ringer solution. Our results demonstrate that at least two insecticidal drimane sesquiterpenes significantly inhibit the spontaneous and serotonin‐stimulated contractions of the crop. The potency of their inhibition correlates with their potency as insecticides, suggesting that visceral muscle inhibition may be responsible for the toxic effects of the compounds on mosquitoes. Moreover, parallel experiments in the crop with a calcium ionophore (A23187) duplicate the effects of the natural compounds, suggesting that they may elicit muscle inhibition by modulating calcium permeability of the crop muscle cells. Future research will investigate the presence and roles of calcium channels within the crop, attempting to better understand their interaction with C. fragrans natural compounds.

Support or Funding Information

Supported by NIH grant R21AI129951.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
LRRC8A/C Voltage‐Dependent Anion Channels Are Required for NADPH Oxidase 1 Activation in Response to TNFα
Authors: Choi Hyehun , Nguyen Hong N. , Dikalova Anna , Lamb Fred S.
Published: June 2021

Tumor necrosis factor‐α (TNFα), a pro‐inflammatory cytokine, is linked to cardiovascular risk. TNFα‐induced superoxide (O2−•) production by NADPH oxidase 1 (Nox1) is required for inflammatory signaling in vascular smooth muscle cells (VSMC). Leucine Rich Repeat Containing 8 (LRRC8) family proteins (LRRC8A, B, C, D and E) comprise volume‐regulated anion channels (VRACs) which are activated by TNFα. VRAC inhibitors suppress the inflammatory response to TNFα, however, the specific subtype of VRAC that is required for this remains to be determined. We hypothesized that a specific type of VRAC is required for Nox1 activation in TNFα signaling. Based upon PCR screening, VSMCs express all five LRRC8 subtypes. However, only knockdown (siRNA) of LRRC8A and C inhibited NF‐κB activation by TNFα (siLRRC8A 49 % decrease, siLRRC8C 31 % decrease). LRRC8D siRNA increased TNFα‐mediated NF‐κB activation (47 % increase). Heterologously expressed LRRC8A and C co‐localized at both the plasma membrane and in intracellular vesicles. LRRC8C knockdown reduced extracellular superoxide production (CAT1H spin trap; siControl+TNFα 1151±25, siLRRC8C+TNFα 774±27 pmol/mg of protein) in response to TNFα as well as TNFα receptor endocytosis (54.5% decrease), subsequent intra‐endosomal superoxide production (CAT1H; siControl+TNFα 201±8.2, siLRRC8C+TNFα 164±9.0 pmol/mg of protein) and proliferation (PCNA protein expression; 31.4 % decrease). These results demonstrate that LRRC8A/C VRACs supports TNFα‐induced Nox1 activity in VSMC. Selective LRRC8A/C inhibition may provide a novel and selective strategy for inhibition of TNFα signaling.

Support or Funding Information

American Heart Association, Scientist Development Grant, 16SDG30610002

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Development of a Self‐assessment Tool to Help Students Develop Metacognitive and Critical Reasoning Skills During High‐fidelity Medical Physiology Simulations
Authors: Kibble Jonathan D. , Harris David D. , Fiore Stephen D. , Garbayo Luciana D.
Published: June 2021

The UCF College of Medicine M.D. curriculum includes a 16‐week Structure and Function module in the first year in which students learn basic medical physiology. The module includes five high‐fidelity simulations that require students to apply physiological knowledge to develop treatment plans in acute care situations. Students work collaboratively in teams of six in a 15 min period to complete a simulation exercise, each of which is followed by debriefs on physiological reasoning and the effectiveness of team process. Past experience has shown that student teams often struggle to identify and organize information and to reach a group consensus about treatment. In this study we developed a survey tool for students to use during a simulation that provides a framework to organize thinking to decision making. The instrument was deployed on an iPad and required each student to first identify sources of information, to list problems requiring attention, to prioritize the problem list and to make a note of physiological rationale. Students could then discuss as group before proceeding to treatment decisions. Each item was followed by a self‐rating of confidence on a 7‐point Likert scale. Eighty out of 120 students gave informed consent for their data to be included in this IRB‐approved study. The most common errors were omission of key information, misconceptions of physiology and over‐treatment of the patient. Despite the prevalence of error students showed high levels of confidence, demonstrating an over‐confidence bias in their decision making. In conclusion the tool shows promise as a way to identify misconceptions in physiology and to reflect on errors in critical reasoning and decision making.

Support or Funding Information

UCF College of Medicine, Medical Education Grant

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Breaking Out From Tradition: Redesign of Large Physiology Lecture Increases Engagement, Inclusion, and Student Outcomes
Authors: Dickey Jordyn , Kimball Kristen , Redden John M.
Published: June 2021

Mounting evidence suggests that traditional lecturing is less effective, less engaging, and less inclusive than active learning. However, transitioning to active learning, particularly in a large science course, presents unique administrative and pedagogical challenges. In this study, we present the results of our recent effort to redesign and restructure our large human anatomy and physiology course at the University of Connecticut.

In place of a traditional lecture, we developed an active instructional model that subdivided hundreds of students into “break out” groups of no more than five students. Breakout groups met concurrently in multiple classrooms during the scheduled lecture time to work through modules in the renal and digestive systems with an undergraduate peer facilitator. Modules were designed with input from undergraduate facilitators, with attention to scientific teaching techniques (active learning, inclusive teaching, assessment). Students concept mapped the molecular basis of urine formation in nephrons and the regulation of acid secretion in the gastric pit; worked through an interrupted case study on ulcer formation and modified think‐pair‐share question sets on renal and gastric pharmacology; and practiced critical reflection on the clinical and socioeconomic factors influencing the incidence and treatment of disease.

At the end of the semester, students registered in the redesigned course were compared to peers registered in another section, taught by the same instructors, that followed a traditional large lecture format. This assessment involved an analysis of student performance on paired exam questions of varied difficulty, a modified SALG (Student Assessment of Learning Gains), and solicited and unsolicited student feedback. Our results indicate that, on average, students in the redesigned course performed better on exam questions related to the renal and digestive systems. Furthermore, many of these questions were found to be less “discriminating”, indicating less disparity between higher performing and lower performing students. The vast majority (95%) of students gave positive feedback on the redesigned classes, and nearly 90% reported learning gains related to the major concepts from the digestive and renal system. Summarily, our study describes and evaluates a new instructional model for large, undergraduate anatomy and physiology courses that has been developed and implemented using undergraduate students. Most importantly, we offer preliminary evidence supporting the conclusion that this model is more inclusive, more effective, and better liked than traditional lecturing.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Multiple Choice Questions to Assess Content‐Specific Critical Thinking in Second‐Year Medical Students
Authors: Yarbrough Tracy L. , Ceryak Susan
Published: June 2021

Background

The need for development of critical thinking skills within future medical practitioners is uniformly appreciated among medical educators, as clinical decision‐making represents a somewhat unique and high‐level application of critical reasoning. Therefore, recent efforts have focused on ways to incorporate critical thinking skill‐building into medical curricula. However, the availability of effective and easily translatable methods to assess content‐specific critical thinking skills, particularly in preclinical curricula, have lagged behind; use of observational assessments such as structured observations of performance is limited by the need for significant faculty time and effort. The objective of this study was to develop and evaluate written assessments (in particular, multiple choice questions) designed to assess students' critical thinking in the context of an organ systems‐based preclinical course. Secondarily, we sought to characterize in‐house questions with regard to their correlation with student performance on a norm‐referenced assessment of critical thinking.

Methods

Students (n=183) enrolled in a second‐year medical school course were recruited for participation. Of these, 19 consented. Student performance on three locally developed multiple choice assessments (CTAs, total of 31 items) was evaluated. In addition, participants completed a pre‐ and post‐course administration of the California Critical Thinking Skills Test for healthcare students (HSRT‐N). Results of multiple choice assessments, HSRT‐N, and overall student performance in the course were analyzed.

Results

Of the eight critical thinking skill components assessed by the HSRT‐N, student performance on CTAs correlated strongly with the analysis component score of the HSRT‐N only (r=0.601). Those questions on the CTAs specifically designed to test critical thinking (n=13) correlated weakly with overall HSRT‐N score, while CTA questions not designed to assess critical thinking (n=18) did not correlate with HSRT‐N score (r=0.298 and 0.097, respectively). Student past course performance and overall CTA score predicted global performance in the course (p<0.001, R^2=0.908), though HSRT‐N score did not.

Conclusion

While critical reasoning can be appraised through observational assessments, its evaluation with written selected response (multiple choice) exams has proven difficult for medical educators; in particular, the development of exams locally to assess specific content and skills. Herein we demonstrate early success with developing multiple choice questions aimed at assessing critical thinking, with correlation to a norm‐referenced assessment. Future efforts may focus on outlining a method for generalizable question development that can predictably assess reasoning as related to medical and biomedical content.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A Byzantine Tarsal Coalition From A Byzantine Monastery
Authors: Throckmorton Zach , Sheridan Susan G.
Published: June 2021

First described by Buffon in 1796, tarsal coalitions encompass any abnormal fibrous, cartilaginous, or bony coalition of any adjacent tarsal bones. Tarsal coalition results from developmental error or injury. Congenital tarsal coalitions arise early in gestation when fibrocartilaginous precursor tarsals fail to completely separate, with more extreme cases rarely occurring when the coalesced cartilage ossifies into fused bones during skeletal maturation (Cowell and Elener 1983). Milder, more common forms are subclinical and are often detected only as an incidental finding of medical imaging ordered for unrelated reasons, therefore the prevalence of tarsal coalition is unknown (Zaw and Calder 2010). However, large‐scale skeletal surveys of recent European‐Americans, recent South Africans of variable ancestry, and medieval Danes all yielded frequencies less than 4% (Case and Burnett 2012). More severe forms can entirely compromise normal mid‐ and rearfoot function and therefore disrupt gait and other locomotor behaviors (Zaw and Calder 2010, Case and Burnett 2012). We report here specimen EBND 6122, a nearly complete and totally, intricately synostotically fused left tarsus and metatarsals I–III recovered from the Byzantine monastery of St. Stephen's in Jerusalem (now the École Biblique et Archéologique Française and Couvent‐Saint Étienne), dating to the Fifth and Sixth Centuries CE. Because of the commingled skeletal deposition at this site, no other skeletal elements can be confidently associated with this individual's foot. We describe how this remarkable pathology affected the individual's gait; succinctly, lack of rear‐ and mid‐foot flexibility likely compromised the normal heel strike and midstance phases of the gait cycle. This specimen adds to the existing archaeological record of tarsal coalitions and is one of the most extreme examples of osseous tarsal coalition in either the clinical or archaeological literature.

Support or Funding Information

This work was supported by the University of Notre Dame and the Arkansas College of Osteopathic Medicine.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Comparative anatomy and development of zebrafish fin muscles: basis for functional, developmental, and macroevolutionary studies
Authors: Siomava Natalia , Shkil Fedor , Voronezhskaya Elena , Diogo Rui
Published: June 2021

Dario rerio is a model organism extensively used in numerous evo‐devo studies devoted to the fin skeletal anatomy and fin‐limb transition. While the skeleton of the paired and median fins of the zebrafish have been described in great detail, little is known about the anatomy and development of the appendicular musculature of this fish. In order to provide a basis for myological, comparative and evolutionary studies, we described for the first time the development, identity, overall configuration, and attachments of all appendicular muscles of D. rerio. We show that the muscle pattern of the caudal fin differs from patterns seen in other zebrafish fins but it is very similar among teleosts in general. This finding supports the idea that developmentally and evolutionary this fin is very peculiar. We describe for the first time interhypural muscles present in the caudal fin of young fishes and absent in adults. The musculature of the adult zebrafish pectoral and pelvic fins is very similar in general, but we note marked differences concerning the development of these muscles. We therefore discuss whether the pectoral appendage might be evolutionary closer to the head than to the pelvic appendage. We provide the anatomical and developmental description of the dorsal and anal fin muscles in zebrafish and describe homologies between the appendicular structures of zebrafish and other fish taxa. We discuss evolutionary trends within these clades to investigate whether the zebrafish is a good model for teleosts in particular and actinopterygians in general. Lastly, we discuss examples of phylo‐devo parallelism that links evolution and development. Our data on the adult phenotype and myogenesis in the zebrafish provide a basis for more integrative developmental, functional, evolutionary, and pathological studies.

Support or Funding Information

This work was supported by Russian Foundation for Basic Research, project nos. 14‐04‐00590 and 17‐04‐01617. The research was done using equipment of the Core Centrum of Insitute of Developmental Biology RAS.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Abnormal development of the paired and median fins in the hyperthyroidism case series of the zebrafish (Danio rerio)
Authors: Siomava Natalia , Shkil Fedor , Voronezhskaya Elena , Diogo Rui
Published: June 2021

Hypo‐ and hyperthyroidism are severe medical conditions frequently found in humans living all over the globe. These diseases are caused by the dysfunction of the thyroid gland and lead to the abnormal embryonic development, various neurological problems, and brain damage. In order to better understand these two conditions in humans, we used zebrafish (Danio rerio) as a model to study the variability of effects of thyroid hormones. We compared normal development of zebrafish fins with pathological series of fishes extensively treated with triiodothyronine (T3) hormone.

Analysis of the fish hyperthyroidism case series revealed certain symptoms similar to those present in human patients. Namely, we observed malformations of the appendicular skeleton and fusion of bones, likely occurred due to the late ossification, as well as significant underdevelopment of the appendicular musculature. Surprisingly, T3 hormone treatment induced excessive myogenesis in the dorsal and anal fin folds where muscles do not normally develop. In addition to various anatomical defects, hyperthyroidism resulted into accelerated growth of fishes in general and led to heterochrony. Interestingly, defects found in our pathological series seem to be similar to defects caused in zebrafishes by stress of the environmental change. These similarities between defects caused by completely different conditions support Pere Alberch's idea of ‘logic of monsters', according to which evolution is so constrained that even when it goes ‘wrong’ ‐ e.g. in cases of severe defects ‐ the resulting phenotypes mirror those seen in other abnormal conditions as well as those seen in the natural variations and/or normal phenotype of other taxa.

These results have crucial implications for both Evo‐Devo research and evolutionary developmental medicine, or ‘Evo‐Devo‐Path’. Specifically, because hyper‐ and hypothyroidism are two disorders frequently found in humans, and because such conditions are deeply connected with heterochrony and thus with micro‐ and macroevolution.

Support or Funding Information

This work was supported by Russian Foundation for Basic Research, project nos. 14‐04‐00590 and 17‐04‐01617. The research was done using equipment of the Core Centrum of Institute of Developmental Biology RAS.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Six2 paralogs are required for proximal tubule development in the Zebrafish pronephros
Authors: Camarata Troy , Hall Corbett , Weyer Alyssa , Drummond Iain , Vasilyev Alexandr
Published: June 2021

The mammalian metanephric kidney develops from reciprocal interactions between the metanephric mesenchyme and ureteric bud (UB) to give rise to a variety of cell types and structures including interstitial cells, vasculature, and epithelial tubules. Progenitor cells adjacent to the UB, termed cap mesenchyme (CM), undergo mesenchymal‐to‐epithelial transition (MET) to form epithelial structures called renal vesicles before elongating and differentiating into nephrons, the functional unit of the kidney. Several genes are expressed in the CM that are required for proper kidney development. One gene encodes the transcription factor Six2, which is known to play a role in self‐renewal of the CM and is turned off in differentiated nephron epithelium. Loss of Six2 in mammals results in renal hypodysplasia due to premature loss of CM. However, Six2 expression persists as cells undergo MET from the CM to form renal vesicles, a structural precursor to differentiated nephrons. Currently, it is not known what role Six2 may play in the differentiation program required to form new nephron epithelium. The zebrafish embryonic pronephros shares features with mammalian nephrons including a similar developmental genetic program and conserved segmentation of the epithelial tubule. Unlike mammals however, the zebrafish pronephros develops directly from the intermediate mesoderm without the need for a continuous population of progenitor cells. This allows the functional study of genes which play a role in CM self‐renewal but also may have roles in cellular differentiation during nephron development. Here we have cloned and characterized the zebrafish Six2 homologs during pronephric development. The zebrafish six2a and six2b genes show conserved expression in the intermediate mesoderm, although with slight differences between the two paralogs. Gene knock‐down, by injection of specific anti‐sense morpholino oligonucleotides (MO) results in kidney cysts and aberrant expression of glomerular and proximal tubule markers, such as wt1a and slc20a1a. Interestingly, distal segments remain intact suggesting Six2 plays a role in cell differentiation of proximal elements of the pronephric nephron.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Comparative Neuroanatomical Study of the Amygdala and Fear Conditioning in Nigerian Breeds of Artiodactyla: Sheep (Uda) and Goats (Red Sokoto)
Authors: Alawa Judith Nkiruka , George Itoro , Hamman Wilson O. , Iliya Ibrahim , Akpulu Peter , Alawa Clement Barikuma
Published: June 2021

Fear conditioning is a behavioural paradigm controlled by the amygdala, in which animals learn to distinguish safety cues from threats and thereby eliciting a range of defensive responses aimed at escaping from the threat. Defensive response to threat occurs either as an active coping strategy involving fight‐or‐flight response or a passive coping strategy involving immobilization‐or‐freezing response. Type of response elicited depends on the repertoire of the specie. This study hypothesized that there will be differences in the defensive response of goats and sheep to threat and these may be related to differences in the neuroarchitecture of the amygdala in these classes of artiodactyla. Fear conditioning was induced by associating the tone of a car horn (neutral stimuli) with water spray (aversive stimuli) and the response to the threat was determined by observation and measuring the flight distances. Furthermore, morphology and morphometry of the neurons in the amygdala was analysed using Toluidine blue and Golgi techniques. Results demonstrated that differences exist in their defensive responses and goats showed stronger active coping strategy with concomitant intense flight distances (p<0.001) compared to the sheep. Histologically, goats showed significantly more densely distributed spiny neurons and packed neuropil in the central amygdala while sheep showed more aspiny neurons in the basolateral complex. Morphometrically, sheep showed greater soma sizes of the pyramidal neurons than goats. These neuroanatomical differences in the amygdala were positively correlated with the defensive responses. This may be the basis for the higher incidence of the sheep in automobile accidents than goats in developing countries especially Africa.

Support or Funding Information

Study was supported by Ahmadu Bello Univesity.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Saphenous nerve morphometry and aging: experimental study in rats.
Authors: Campos Stella Andrade Rodrigues , Neri Letícia Oliveira , Sanada Luciana Sayuri , Fazan Valéria Paula Sassoli
Published: June 2021

The saphenous nerve is a sensory nerve of the leg and foot, being the terminal branch of the femoral nerve, from the lumbar plexus. Because it is long and constant and presents a superficial pathway, it becomes a good experimental model for investigations of neuropathies. We know that the peripheral nerves undergo morphological and functional changes with aging. However, changes in the saphenous nerve as a consequence of aging have not been widely investigated. We investigated the probable changes in saphenous nerve morphology and morphometry in Wistar rats with different ages: 180 (n = 6), 360 (n = 6) and 720 (n = 6) days of life. Semithin cross sections (0.5 μm) of the nerves, stained with toluidine blue, were observed with a light microscope and the morphometry of fascicles and myelin fibers was performed through a computer program, taking into account the area and diameter of the fascicles, myelin fibers and their respective axons, number of myelin fibers and their density, and the myelin sheath area and G ratio of myelinated fibers. Statistical comparisons were performed between proximal and distal segments on the same side and between sides for segments of the same level at the same age, and between ages. Differences were considered significant when p <0.05. The presence of morphological changes in the myelin fibers (loss of circularity, demyelination, presence of myelin folds and balls) and in the endoneural capillaries (basement membrane thickening and endothelial hyperplasia) were visually detected in the nerves of 720 days old animals. Morphometry showed a reduction in the size of the axon and the G ratio, with a shift to the left of the G rate distribution histograms in animals with 720 days of life. Our results suggest the presence of axonal neuropathy due to aging.

Support or Funding Information

FAEPA, CAPES and CNPq

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Decreased Density of Cholinergic Interneurons in the Medial Caudate Nucleus in Humans with Williams Syndrome
Authors: Hanson Kari L. , Cuevas Deion L. , Groeniger Kimberly M. , Lew Caroline H. , Hrvoj‐Mihic Branka L. , Raghanti Mary Ann , Bellugi Ursula , Halgren Eric , Semendeferi Katerina
Published: June 2021

Williams syndrome (WS) is a rare neurodevelopmental disorder caused by the hemideletion of approximately 25–28 genes at 7q11.23. Its unusual social and cognitive phenotype is most strikingly characterized by the disinhibition of social behavior, in addition to reduced global IQ, with a relative sparing of language ability. Hypersociality and increased social approach behavior in WS may represent a unique inability to inhibit responses to specifically social stimuli, and is likely rooted in part in abnormalities of frontostriatal circuitry. Recent research has demonstrated that selective ablation of striatal cholinergic interneurons (SCINs) results in significant increases in compulsive conspecific‐directed, but not object‐focused, exploratory behavior in mice, indicating a role for SCINs in social approach behavior. Here, we examined the density of SCINs and parvalbumin‐positive interneurons in the striatum of five postmortem specimens from subjects with WS and five typically‐developing (TD) subjects. We found a significant reduction in the density of SCINs in the medial caudate nucleus, an important region receiving cortical projections from the orbitofrontal and ventromedial prefrontal cortex in circuitry involved in language and reward systems. This pattern of decreased SCIN density in WS is contrasted by anatomical findings in other disorders, including Tourette syndrome and schizophrenia, where differing patterns of SCIN depletion are found. Taken together with findings from neuroimaging, differences in the brains of individuals with WS at both the macro‐ and microstructural level further indicate a role for frontostriatal circuitry in the disorder's distinctive behavioral phenotype.

Support or Funding Information

This research is supported in part by NIH #P01NICHD033113, #1R03MH103697‐01(KS), and a Wenner Gren Dissertation Fieldwork Grant (KLH).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The relationship between radial optic flow perception and neurodegeneration in Parkinson's Disease: A voxel‐based morphometric MRI analysis
Authors: Maskalo Guttu , Thompson John A. , Kleptiskaya Olga , Pelak Victoria S.
Published: June 2021

Symptomatic navigational veering in Parkinson's disease (PD) is related to abnormal processing of radial optic flow, or the motion patterns perceived during foreword self‐movement. Previous studies indicate an important role of the parietal cortex in the perception of radial optic flow. However, the link between radial optic flow perception, cortical degeneration, and disease severity in PD has not been explored. The aim of this study is to better understand the correlation between three‐dimensional radial optic flow perception in PD and cortical degeneration in area V6 of the parietal lobe. The V6 region is important for the analysis of visual motion patterns during self‐motion, and therefore navigation. We hypothesized that evidence for degeneration in area V6 correlates with radial optic flow measures in PD patients. Voxel‐based volumetric MRI data analyses using FreeSurfer, focusing on area V6 as the region of interest, was performed on MR brain images from 19 PD patients. Results correlated to radial optic flow measures and PD disease severity measured by Unified Parkinson's Disease Rating Scale (UPDRS), part 3. Correlation analyses were also conducted between the visual pathway and the basal ganglia, since both are linked to PD pathology.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Histone deacetylases in axonal growth and regeneration and their relevance to Parkinson's disease.
Authors: O'Keeffe Gerard
Published: June 2021

Functional decline in Parkinson's disease (PD) is the cumulative result of regulatory alterations affecting large numbers of genes involved in various aspects of neuronal maintenance and function, and it has recently emerged that axonal degeneration plays a key role. Central to the alterations in gene expression that underlie this failure of axon maintenance, is the regulation of gene transcription by enzymes known as histone deacetylases (HDAC) which promote the de‐acetylation of histone proteins to inhibit transcription. alpha‐synuclein, a key protein that accumulates in the brains of patients with the disease, binds histone proteins in vitro & in vivo, and nuclear a‐synuclein reduces acetylated histone 3 (AcH3) levels. However while these molecular insights are important, how they regulate the neuronal structure and axonal growth in neurons affected by Parkinson's, and the relevance of this cell biology approach to the human brain is unknown.

Here we used a network approach to identify all genes that had a significant positive (r+) or negative (r−) correlation with the expression of all HDACs using microarray data from the human substantia nigra (SN; GSE 60863). We then conducted a detailed enrichment analysis to identify biological pathways that were over‐represented and may be linked to Parkinson's Disease. These analyses showed that Class‐II but not Class‐I HDACs were significantly correlated with functional pathways linked to Parkinson's Disease (p<0.0001). These included genes linked to familial Parkinson's Disease and oxidative phosphorylation, including those associated with mitochondrial complex I.

To link these data with changes in neuronal structure, we next examined the effects of class specific HDAC inhibitors on neuronal structure by examining a range of HDAC inhibitors for their ability to promote axonal growth and branching in dopaminergic and sympathetic neurons which are the two main cell types that undergo progressive axonal degeneration in Parkinson's Disease. We found that a MC1568 (a class II inhibitor) but not MS275 (a class I inhibitor) promoted significant increases in axon growth and branching (p<0.01). Therefore we further examined the therapeutic potential of MC1568, and found it protected against the detrimental effects of MPP+‐ and alpha‐synuclein induced axonal degeneration in a models of Parkinson's disease.

This study therefore provides new insights into the regulator mechanisms that control axonal growth in neurons affects by Parkinson's, and highlights the potential of using this approach to identify therapeutic targets for neuroprotection and axonal regeneration.

Support or Funding Information

This work was funded by a Career Development Award from Science Foundation Ireland under the grant number 15/CDA/3498.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Epigenetic Regulation of Oncogenes in Leukemia by the Ikaros Tumor Suppressor
Authors: Payne Jonathon Lee , Dovat Elanora , Song Chunhua , Dovat Sinisa
Published: June 2021

The IKZF1 gene controls expression of the Ikaros protein which functions as a tumor suppressor in pediatric acute lymphoblastic leukemia (ALL). Dysfunction of Ikaros due to deletion or an inactivating mutation of a single allele is associated with high‐risk ALL, increased risk for relapse, and poor prognosis. Ikaros is a transcriptional regulator of a large set of target genes; however, the mechanism by which Ikaros regulates gene expression in leukemia and mediates its tumor‐suppressor effect has yet to be fully elucidated. In this study, chromatin immunoprecipitation with next‐generation sequencing (ChIP‐Seq) was used to identify Ikaros' target genes and their epigenetic signature. ChIP‐Seq results were confirmed using quantitative chromatin immunoprecipitation (qChIP). Ikaros gain‐ and loss‐of‐function assays were used to determine the role of Ikaros in the epigenetic regulation of gene expression which was assessed by quantitative, real‐time PCR (qRT‐PCR) and western blot. ChIP‐Seq and qChIP assays identified a large number of target genes that are regulated by Ikaros. Ikaros gain‐ and loss‐of‐function experiments in combination with qChIP “scanning” at Ikaros target gene promoters revealed that Ikaros can repress transcription by inducing the formation of heterochromatin at gene promoters. Ikaros overexpression in ALL results in an increase in H3K27me3 and H3K9me3 repressive chromatin markers at the promoters of genes that support cell cycle progression and the phosphoinositide 3‐kinase (PI3K) pathway—both pathways are frequently activated in cancer. We also demonstrate that Ikaros overexpression results in the transcriptional repression of the JARID1B/KDM5B histone demethylase. Decreased KDM5B expression is accompanied by a genome‐wide increase in H3K4me3 as evidenced by western blot. In conclusion, our results show that Ikaros' tumor suppressor activity in high‐risk ALL involves epigenetic regulation at the promoters of its target genes and regulation of H3K4me3 levels via transcriptional repression of the JARID1B histone demethylase. These data give further insight into the mechanisms underlying Ikaros' tumor suppressor function in acute lymphoblastic leukemia.

Support or Funding Information

This work was supported by National Institutes of Health (NIH) Grant R01 HL095120, a St. Baldrick's Foundation Career Development Award, a Hyundai Hope on Wheels Scholar Grant Award, the Four Diamonds Fund of the Pennsylvania State University College of Medicine, and the John Wawrynovic Leukemia Research Scholar Endowment.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.