bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunohistochemical Characterization of Hepatic Progenitor Cell Niche in Liver Fibrosis of Elderly Cadavers
Authors: Mak Ki Mark , Chiu Sophia
Published: November 2023

Human hepatic progenitor cells (HPC) normally reside in a quiescent state in the canals of Hering (COH) located at the interface between the portal tract and periportal parenchyma of the liver lobule. In chronic liver injury, HPC become activated and differentiate into cholangiocytes and hepatocytes, contributing to hepatic regeneration. HPC activation, termed ductular reaction or hepatic response, is accompanied by development of a HPC niche composed principally of laminin matrix, myofibroblasts and macrophages. The composition of the niche is likely to be a determinant of HPC behavior. Preliminary studies found activation of HPC in the periportal parenchyma and occurrence of HPC deep in the liver lobule of elderly cadavers with progressive stages of liver fibrosis (FASEB 2006; 30:1044.4; 1044.5). The present study assessed the composition of the niche proteins and fibrogenic cells in liver fibrosis of elderly cadavers by immunohistochemistry. HPC are ~ 8 μm in size showing an oval to cuboidal morphology with scant cytoplasm and express cytokeratin 7 (CK7), CK19 or epithelial cell adhesion molecule. Immunostaining showed that the COH were marked by a basement membrane positive for collagen IV and laminin. The niche surrounding the COH contained a rich collagenous matrix, revealed by Sirius red stain for collagens. Moreover, the matrix displayed an array of fibrillar collagen I, III and V and filamentous collagen VI. Hepatic stellate cells/myofibroblasts labeled by a‐smooth muscle actin were present in the collagenous matrix surrounding the COH. In the periportal parenchyma where ductular reaction occurred in response to fibrogenesis, reactive ductules composed of strings of HPC were marked by collagen IV and laminin and surrounded by a collagenous matrix containing collagen fibers and fibrogenic cells. Similarly, collagens and fibrogenic cells were observed in the matrix associated with isolated HPC in the deeper part of the lobule, as well as in the HPC‐containing ductules in the developing fibrous septa and bridging septa.

Conclusions/implications

The HPC niche contains collagen IV and laminin that provide a basement membrane supporting the COH and HPC. The laminin matrix supports HPC in an undifferentiated phenotype and suppresses hepatocye differentiation. The collagen fibers confer strength on the matrix scaffolds of the HPC niche. Moreover, while collagen V regulates fibrillogenesis of collagen I, collagen VI, a connecting protein, links fibrillar collagens to the niche matrix. Collagen V and VI also bind cytokines, growth factors and matrix metalloproteinases, regulating their availability to HPC. Hepatic stellate cells/myofibroblasts contribute to remodeling of the HPC niche matrix. The composition of the niche matrix likely influences the HPC fate in the aged liver.
Identification and Characterization of Bacterial and Host Factors Involved in Microtubule Disassembly in Epithelial Cells during Edwardsiella Infections
Authors: Aggarwal Priyanka , Wang Qiyao , Liu Qin , Leung Ka Yin , Guttman Julian Andrew
Published: November 2023

Enteric bacteria from the genus Edwardsiella cause great losses to a variety of commercially important fish such as the Japanese Eel, Channel Catfish and Turbot. In humans, they cause a gastroenteritis‐like phenotype. These bacteria are known to infect both inflammatory and epithelial cells. Although macrophages are by far the best‐studied cell types during these infections, epithelial cell studies have lagged primarily due to poor infection models. Because these bacteria resemble other intestinal pathogens and because the host cytoskeleton is a common target of intestinal pathogens, we hypothesized that similar infections could be established to evaluate host actin, intermediate filament and microtubule alterations. Here we established two different epithelial cell infections using HeLa and CaCo‐2 cells and demonstrate that only the microtubule cytoskeleton is noticeably altered by these bacteria. We found that microtubules are initially severed then completely disassembled during Edwardsiella infections. To identify the bacterial and host components involved in this phenotype, we screened a 2,758 mutant Edwardsiella genome transposon insertion library and localized all known host microtubule‐severing enzymes (katanin, spastin, and fidgetin). Using the screening approach we were able to narrow the 2,758 Edwardsiella mutants/genes to 15 that are key players in causing MT disassembly in epithelial cells. Immunolocalization experiments showed the katanin subunit A‐like 1, katanin subunit B 1, and katanin subunit B‐like 1 at microtubule cut sites, suggesting their involvement in the microtubule disassembly event. This work not only provides the first evidence of host cytoskeletal alterations during Edwardsiella infections, but also provides a resource for further characterization of molecular components involved in microtubule disassembly in general.

Support or Funding Information

Funding source: Natural Sciences and Engineering Research Council of Canada (NSERC)and SFU BISC department funds
Palladin Can Compensate for Arp2/3 Complex Defects and Structurally Organizes Actin‐Rich Structures Generated during Listeria monocytogenes Infections
Authors: Dhanda Aaron S , Vogl A Wayne , Otey Carol A , Beck Moriah R , Guttman Julian A
Published: November 2023

The actin cytoskeleton is co‐opted by the invasive and motile bacteria Listeria monocytogenes (Listeria) for their entry, intracellular motility and dissemination from one cell to another. Once inside host cells, these bacteria are propelled by bacterially‐generated, Arp2/3‐based, actin‐rich structures called comet tails. The host protein palladin is a crucial actin crosslinker of motile actin‐based structures generated during eukaryotic cell motility. Recently, palladin has been shown to nucleate branched actin filament arrays in vitro. Whether this new actin‐nucleating role of palladin is involved in powering cell motility remains unknown. Here we set out to test the hypothesis that palladin is a crucial component of bacterially‐induced actin‐rich structures generated during Listeria infections and simultaneously used Listeria as a model to uncover new physiological functions of palladin. Through immunofluorescence microscopy we initially identified palladin at sites of bacterial entry and at motile comet tails. Infections of epithelial cells depleted of palladin through RNAi revealed that palladin was dispensable for bacterial invasion. However, when comet tails were examined, we found that they were significantly shorter and severely misshapen in the absence of palladin. Furthermore, when palladin mutants defective for actin or VASP binding were overexpressed, comet tails either disintegrated at their distal ends or became progressively thinner as they moved, suggesting that palladin is a crucial organizer of the actin arrays within comet tails. Using electron microscopy, we further demonstrated that comet tail thinning resulted in switching of the actin network from branched actin arrays to parallel actin bundles. Finally, to determine if palladin's actin‐nucleating function could compensate for the Arp2/3 complex during comet tail motility, we overexpressed palladin in cells treated with the Arp2/3 inhibitor CK‐666. Remarkably, in the presence of CK‐666, Listeria could initiate and maintain comet tail motility in palladin overexpressing cells, whereas Listeria motility immediately ceased in cells with endogenous levels of palladin. Taken together we show that palladin is essential for normal comet tail function as well as morphology, and when overexpressed, can compensate for Arp2/3 complex functional defects during bacterial actin‐based motility.

Support or Funding Information

Grant Funding Source: NSERC (grant no. 355316 to J.A.G and grant no. 155397‐2013 to A.W.V), NIH and SFU departmental funds
IP3R, TRPM6 and Homer1 are Localized to ER‐PM Contact Sites at Tubulobulbar Complexes in Rat Testis
Authors: Adams Arlo , Vogl A. Wayne
Published: November 2023

The seminiferous epithelium is the site of spermatogenesis; the cellular basis for male fertility. Large junction complexes between Sertoli cells act to control the movement of differentiating spermatogenic cells while those between Sertoli cells and late spermatids connect these late spermatids to the apex of the epithelium. During spermatogenesis, turnover of these junction complexes must occur so that the next generation of spermatogenic cells can move into the epithelium, and mature spermatozoa can be released into the seminiferous tubules. Structures called Tubulobulbar Complexes (TBCs) have been implicated in junction turnover due to their appearance during turnover and their necessity in allowing sperm release. TBCs likely drive the internalization of junction complexes but how Sertoli cells control the development and degradation of TBCs is unknown. TBC regulation may be a product of a well‐known yet functionally unestablished contact site between TBC bulbs and cisternae of ER. Because calcium exchange occurs at other ER‐plasma membrane contact sites such as those between ER and endosomes, we chose to probe for the IP3R calcium channel. Using bioinformatics, we found potential protein binding partners for IP3R in the form of the TRPM6 plasma membrane calcium channel and the homer1 scaffolding protein. Using a high‐resolution pre‐embedding immunoelectron microscopy technique we localized all three proteins to the TBC‐ER contact site. This data suggests the potential for scaffolding of IP3R to TRPM6 via homer1 at TBC‐ER contacts and opens up the possibility for calcium exchange as an important function of the ER at these sites.

Support or Funding Information

Supported by a NSERC Discovery Grant (#155397‐2013) to AWV
Cadherin‐6B Proteolysis Controls The Neural Crest Cell Epithelial‐to‐Mesenchymal Transition Through Transcriptional Regulation
Authors: Taneyhill Lisa
Published: November 2023

During epithelial‐to‐mesenchymal transitions (EMTs), cells disassemble cadherin‐based adherens junctions to segregate from the epithelia. Chick premigratory cranial neural crest cells reduce Cadherin‐6B (Cad6B) levels through several mechanisms, including proteolysis, to permit their EMT and migration. Serial processing of Cad6B by ADAMs and γ‐secretase generates an intracellular C‐terminal fragment (CTF2) that could acquire additional functions independent of full‐length Cad6B. Here we report that Cad6B CTF2 possesses a novel pro‐EMT role by up‐regulating EMT effector genes in vivo. Following proteolysis, CTF2 remains associated with β‐catenin, which stabilizes and redistributes both proteins to the cytosol and nucleus, leading to an increase in β‐catenin, CyclinD1, Snail2, and Snail2 promoter‐based GFP expression in vivo. A CTF2 β‐catenin‐binding mutant, however, fails to alter gene expression, indicating that CTF2 modulates β‐catenin‐responsive EMT effector genes. Notably, CTF2 associates with the endogenous Snail2 promoter in the cranial neural crest, providing, for the first time, evidence that a cadherin CTF2 can bind to chromatin in vivo. Furthermore, this association with chromatin is dependent upon an intact β‐catenin‐binding domain within CTF2. Collectively, our data reveal how Cad6B proteolysis orchestrates multiple pro‐EMT regulatory inputs, including a reduction in adhesion within the premigratory neural crest cell population and up‐regulation of the Cad6B repressor Snail2, to ensure proper cranial neural crest cell EMT and appropriate patterning of the vertebrate embryo.

Support or Funding Information

This work was supported by NIH grants R01DE024217 and F32DE022990 and a Research Scholar Grant, RSG‐15‐023‐01‐CSM, from the American Cancer Society.
Investigating UBA1 distribution and its relevance to Spinal Muscular Atrophy
Authors: Maani Amr , Shorrock Hannah , Gillingwater Tom
Published: November 2023

Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disease characterized by the degeneration of lower motor neurons. SMA is the most common genetic cause of infant mortality and is caused by a homozygous deletion of the Survival Motor Neuron 1 gene (SMN1). There is currently no effective therapy. However, experiments on animal models targeting UBA1 pathways have shown improvements in neuromuscular phenotype. Studies have shown that there is a reduction of UBA1 in SMA and that mutations in UBA1 can cause X‐linked SMA. Nevertheless, the mechanism by which UBA1 mediates degeneration in SMA is unclear. This project investigated the role of UBA1 in SMA and, more specifically, the relevance of sub‐cellular UBA1 distribution in SMA. UBA1 distribution in post‐mitotic cells, including cultured primary neurons, was studied to identify whether UBA1 distribution is disrupted in cell models of SMA. UBA1 distribution was also studied in HEK293 cells to confirm the distribution in dividing cells. This study confirmed that UBA1 distribution changes over time in cultured motor neurons and that there is a reduction of nuclear UBA1 in SMA motor neurons. Results suggest that understanding UBA1 distribution in SMA will be essential to future studies in reaching a therapeutic cure.

Support or Funding Information

The University of Edinburgh
Changes in the extracellular matrix following ischemic stroke in the rat
Authors: Patel Monal , McClain Allison , Meyer Alice , Andrews Ellen
Published: November 2023

Ischemic strokes results in immediate inflammation and neuronal cell death. The amount of functional recovery that is seen following a central nervous system (CNS) injury is limited. Recent studies have shown that chondroitin sulfate proteoglycans (CSPGs) contribute to the lack of functional plasticity due to their inhibition of neurite outgrowth. Previous research indicates that there is limited neuroplasticity (neurite outgrowth) from the uninjured contralateral hemisphere and this neuroplasticity can be enhanced with various therapeutic treatments (anti‐nogo, adult human bone marrow stem cells, etc.). Astrocytes and microglia are involved in the post‐ischemic inflammatory response, and contribute to the changing extracellular matrix (ECM) by both producing CSPGs and producing enzymes that can alter CSPGs and the ECM in the ischemic core and penumbra region. Alterations to CSPG expression, the ECM and the glial response may be altered in the contralateral sensorimotor cortex to allow for the limited neuroplasticity seen after injury. In the present study, we investigated glial activation and CSPG expression in the sensorimotor cortex after an ischemic stroke in the rat, both ipsilateral and contralateral to the lesion 3, 7, 14 and 28 days post stroke. Both neurocan expression and GFAP expression increased at 14 days in the ipsilateral sensorimotor cortex. Total neurocan expression is significantly increased 14 days post stroke in the ipsilateral sensorimotor cortex as compared to control. GFAP expression (indicative of activated astrocytes) is significantly increased in the sensorimotor cortex surrounding the lesion at 14 days post stroke as compared to control. Both aggrecan and CD11b (microglia) expression are stable at 3 and 14 days post stroke as compared to controls. Western blot analysis of CSPG expression at 7 days and 28 days post injury is under investigation. CSPG distribution at all time points (3 day, 7 day, 14 day, 28 days post injury) is being analyzed via immunohistochemistry.

These results may help pinpoint the best time and location of treatment to help restore function following an ischemic stroke.

Support or Funding Information

Supported by Midwestern University
Therapeutic effects of long‐term systemic adipose‐derived stem cell conditioned medium in a mouse model of amyotrophic lateral sclerosis
Authors: Walker Chandler L. , Kennedy Felicia M. , Fry Colin M. E. , Iyer Abhirami K. , Du Yansheng , March Keith , Jones Kathryn J.
Published: November 2023

Amyotrophic lateral sclerosis (ALS) is a devastating progressive neurodegenerative disease involving motor neuron (MN) loss, muscle paralysis and death. The gold standard animal model of ALS, the superoxide dismutase 1 (SOD1) transgenic mouse model exhibits similar clinical progression through pre‐symptomatic, symptomatic, and end stages of disease. Disease onset occurs pre‐symptomatically by 47 days of age in SOD1G93A mutant mice. Prior research revealed initial hindlimb muscle denervation, with progressive neuromuscular junction (NMJ) loss over time. Our previous data indicate systemic daily therapy of adipose‐derived stem cell conditioned medium (ASC‐CM), beginning at symptom onset, delayed onset and symptom progression and extended survival in SOD1G93A mice, suggesting a central mechanism of action. In addition, we observed that daily ASC‐CM therapy starting at 35 days of age, when NMJ innervation resembles non‐diseased mice, significantly attenuated NMJ loss by day 47 in SOD1G93A mice. We then hypothesized that long‐term systemic ASC‐CM therapy could potentially provide enhanced functional and survival benefits through both peripheral and central mechanisms compared to post‐symptom onset therapy. To test this hypothesis, sixteen SOD1G93A and sixteen wild‐type (WT) mice received either systemic daily ASC‐CM or vehicle control medium beginning at 35 days of age until day 63, followed by a twice‐weekly treatment regimen until animal end stage. Starting at 63 days of age, we performed a battery of behavioral assessments testing gait, grip endurance, tail elevation, and rearing, among other behaviors, to identify any therapeutic effects on symptom onset and progression. At end stage, NMJ innervation of the medial gastrocnemius muscle and lumbar motor neuron survival will be assessed. Though the study is still underway, initial analyses have identified possible functional benefits of long‐term ASC‐CM therapy. Based on our previous pre‐symptomatic and symptomatic treatment data, we predict that systemic ASC‐CM therapy may prevent hindlimb muscle denervation and act centrally to ameliorate functional decline and impart survival benefits in the SOD1G93A ALS mouse model.

Support or Funding Information

NIH T32 HL79995 (CLW); IU Collaborative Research Grant 2214076 (KJJ & KM)
DNA methylation and mRNA expression in the dmPFC are altered after protracted withdrawal from cocaine self‐administration
Authors: Ploense Kyle , Vieira Philip , Kippin Tod
Published: November 2023

Cocaine addiction is a chronic disorder that involves excessive, uncontrolled drug consumption. Both humans and rodents will escalate the amount of cocaine taken when it is readily available indicating that excessive intake is dependent on prior consumption. In rodents, however, escalation is not observed when access is restricted to “limited” (i.e. 1 hr) daily sessions. Here, we investigated whether control over drug intake or drug exposure are the critical factors in escalation by employing a mixed limited‐contingent exposure and prolonged noncontingent exposure model. . Rats were implanted with a permanent jugular catheter and then allowed to lever press to self‐administer (FI20 with a 20 s light cue paired with each infusion) saline vehicle (0.1 ml/infusion) or cocaine (0.25 mg/infusion) under 3 conditions: limited‐access (1 h/ day), extended‐access (6 h/day), and 1 h limited‐access + 5 h non‐contingent exposure (via yoking to extended access rats) to cocaine. Based on the first 10 min and first hour of daily access, we observed rapid escalation of cocaine intake in both the extended‐access and limited‐access + non‐contingent conditions (ps < 0.05). We also observed a delayed escalation of cocaine intake in the limited‐access condition within the first 10 min of self‐administration (p < 0.05), but not across the 1 h of cocaine availability. Interestingly, escalation of cocaine intake was accelerated in the limited + non‐contingent‐access condition relative to the extended‐access condition. However, relative to the other cocaine conditions, the limited‐access + non‐contingent group exhibited markedly more non‐reinforced responses indicating that distinct behavioral mechanisms drive escalation by contingent versus noncontingent drug exposure (ps<0.05). Additionally, post‐mortem quantification of homer2 (a gene implicated in cocaine intake and associated) mRNA expression within the dmPFC indicated elevation only in the extended‐access conditions (p<0.05). Rises in homer2 mRNA were associated with distinct levels of DNA methylation, hydroxymethylation, and transcription factor binding to the Homer2 gene. Together, these findings indicate that either contingent or non‐contingent “excessive” cocaine exposure supports escalation but have differential effects on the temporal patterning of operant responsiveness as well as molecular correlates of escalation.

Support or Funding Information

This research was supported by NIH grants DA‐027115 and DA‐027525 (TEK) and DA024038 (KKS), as well as funding from and the W.M. Keck Foundation (TEK)
Different expression of miRNA in the elderly with cognitive impairment and control group in aluminum exposed mining area
Authors: Ma Huina , Huang Hehua , Tang Lingling , Zhou Shanjin , Chen Bingpu , Ling Yanwu
Published: November 2023

Alzheimer's disease (AD) is a nerve degenerative disease, it's intimately connected with the genetic and environmental factors. Previous work showed high aluminum exposure may be a risk factor of AD in the mining area. The dysregulation of miRNA expression has been found to be closely associated with AD. Cognitive function was measured by mini‐mental state examination(MMSE). The contents of trace elements (Al) in blood were determined using ICP‐AES. We analyzed the expression of miRNAs in peripheral blood of a total of 360 Cognitive impairment group (n=156) and healthy controls (n=204) by quantitative reverse transcriptase polymerase chain reaction (qRT‐PCR). Data assays show 7 miRNAs displayed significantly different expression levels in Cognitive impairment group serum compared with controls in aluminum mining area. Indicate that deregulated miRNAs in blood might be used as biomarkers in the diagnosis of early AD or other dementia disease.

Support or Funding Information

Supported by National Natural Science Foundation of ChinaNO.31560294
Morphological and Physiological Characterization of Cortical Subplate Neurons in Forebrain‐Specific Ctgf Knockout Mice
Authors: Lu Yi‐Ling , Lee Li‐Jen
Published: November 2023

In the cerebral cortex, connective tissue growth factor (CTGF) is expressed in distinct areas, including the subplate, which plays important roles in the cortical development. However, the function of CTGF in subplate neurons is unknown. To resolve this issue, we generated forebrain‐specific Ctgf knockout (FbCtgf KO) mice using the Cre‐Lox strategy in which loxp‐flanked full‐length Ctgf is removed by Emx1 driven Cre in the excitatory neurons of the forebrain structures. In FbCtgf KO mice, the expression of Ctgf is abolished yet the subplate neurons are still present. We then examined the morphological and physiological features of the subplate neurons in these mutants. Compared with those in control mice, the subplate neurons in FbCtgf KO mice exhibited altered dendritic branching pattern including fewer bifurcating nodes, terminal endings and shorter dendritic length. In the physiological aspect, the resting membrane potential, input resistance and membrane time constant were not altered by Ctgf removal in the subplate neurons, whereas greater membrane capacitance was noticed in FbCtgf KO mice. The properties of action potential were comparable among the control and mutant mice. Together, our results revealed the roles of Ctgf in modulating the membrane property and dendritic complexity in cortical subplate neurons.
Motor neuron scaling and somatic growth in normal and transgenic rainbow trout, Oncorhynchus mykiss
Authors: Anderson Curt W , Feurborn Ethan T , Bradley Terence M , Rodnick Kenneth J
Published: November 2023

Teleost fishes demonstrate indeterminate growth and a dramatic increase in body mass over their life cycle. Myotonal muscle mass comprises >60% of the adult body mass in active species and effective growth and development of functional capability requires interactions between multuinucleated muscle fibers (myocytes) and motor neurons. Basically, as all organisms grow and develops, the nervous system must compensate for the change in size. While numerous studies have examined myogenesis, muscle fiber recruitment and hypertrophy, and phenotypic plasticity in fishes, our understanding of the myocyte/neuron linkage during development is extremely limited. The goal of this project is to determine how motor neurons in rainbow trout change through development and how this change can be viewed through principles of scaling. Sections of spinal cord were removed at the rostral, medial, and caudal positions from normal and genetically modified rainbow trout to overexpress follistatin, which antagonizes myostatin and increases myotonal muscle. Increased muscling in these transgenic trout is due primarily to myocyte hyperplasia. Spinal cords (n= 35) were sectioned on a microtome and stained with acridine orange. Sections were analyzed to 1) measure the cross sectional area of the spinal cord and ventral horn motor neurons and 2) determine how motor neurons develop to compensate for growth in total muscle mass. The average motor neuron area from normal rainbow trout revealed an unusual allometric relationship compared to endothermic animals. As the mass of the fish increased there was a positive (r2 = 0.961) correlation to the motor neuron area. Compared with normal rainbow trout, transgenic trout had an average neuron area similar to that of the normal trout, but relative to per gram of body mass motor neuron is significantly less, suggesting that the motor unit size – the number of skeletal muscle fibers per motor neuron ‐ increases with an increase in muscle mass. Previous studies suggest that neuron size in endothermic organisms follow a pattern of metabolic allometric scaling, yet motor neuron from ectotherms in this study had scaling coefficient of just 0.204. These findings suggest that as the axial muscle increases mass in normal and transgenic rainbow trout, the peripheral nervous system is not undergoing a similar growth in neuron size.

Support or Funding Information

NIH Grant #P20 RR0116454
Swine Barn Dust Exposure Activates Microglia through Induction of Oxidative Stress and the Resultant Neuroinflammation Appears to Involve HMGB1 and RAGE Signaling
Authors: Massey Nyzil , Puttachary Sreekanth , Mahadev‐Bhat Sanjana , Shrestha Denusha , Kanthasamy Anumantha G , Charavaryamath Chandrashekhar
Published: November 2023

Large swine farms employ full time workers who are exposed to occupational contaminants including organic dust, LPS, peptidoglycan and gases. Exposed workers mainly report bronchitis, asthma and loss of lung function. Most studies have focused on mechanisms of inflammation underlying respiratory symptoms. But effect of a continued exposure to swine barn dust on other vital organs such as brain have not been studied. Brain microglial cells are similar to macrophages of other organs in immune activation. Therefore, we tested a hypothesis that swine barn dust extract (SBDE) activates microglial cells of the brain.

Settled dust from commercial swine operations was collected, buffer extract prepared and filter sterilized. Mouse microglial cell line (C57BL6) were treated with SBDE or lipolysachharide (LPS) or peptidoglycan (PGN) or medium and stained for the expression of, Iba1, gp91 phox (reactive oxygen species indicator), HMGB1 (high‐mobility group box‐1), RAGE (receptor for advanced glycation end products) and DAPI at 0, 6, 12, 24 and 48 h post treatment.

Microglia morphologically appeared reactive with an upregulation gp91 phox by 24 hours post PGN or SBDE treatment. At 48 hours, SBDE treated microglia demonstrated translocation of nuclear HMGB1 into the cytoplasm. RAGE (transmembrane) was co‐localized with cytoplasmic HMGB1 in SBDE treated microglia.

All these findings demonstrate that swine barn dust exposure can cause activation of microglia and induce oxidative stress. The resultant neuroinflammation appears to involve HMGB1 and RAGE signaling.

Support or Funding Information

Iowa State University, Ames, IA
Sleep, glymphatic activation and phantosmia inhibition
Authors: Henkin Robert I , Abdelmeguid Mona
Published: November 2023

Phantosmia occurs in about 60% of the many thousands of patients who develop smell loss. It is described as a distorted, unpleasant olfactory sensation in the nose in the absence of any external odor. It can be birhinal or unirhinal. It is usually rotten or chemical in character and overwhelmingly unpleasant. It usually occurs daily, usually spontaneously, lasting for minutes to hours. Patients with unirhinal phantosmia report that after sleep, even for as short as 20 minutes, causes their phantosmia to be inhibited and to disappear. We have studied over 30 patients with this phenomenon. By use of functional magnetic resonance imaging of brain we observed that multiple brain sites, in addition to those mediating olfaction, were activated with phantosmia. By use of magnetic resonance spectroscopy we measured lower than normal brain levels of gamma‐aminobutyric acid (GABA) in brain regions in which phantosmia activation occurred. Treatment with GABAergic drugs or with repetitive transcranial magnetic stimulation activated and increased brain GABA which inhibited phantosmia in addition to sleep. Based upon these observations we hypothesize that sleep, even as short as 20 minutes (consistent with phase 2 sleep), through its action in glymphatic activation, activates brain GABA and inhibits phantosmia by reestablishing brain homeostasis. This effect on brain plasticity may be mediated through a complex series of events by which astrocyte activation, which themselves are GABAergic cells, initiate the glymphatic cascade of events, directly activating GABA and GABA receptors and through G‐protein coupled activation mediates calcium signaling which thereby inhibits phantosmia.

Support or Funding Information

There is no sources of funding to declare.
An effective workshop model for graduate student and postdoctoral fellow career development
Authors: Feeney Shea , Barral José M. , Hendershot Jenna M. , Hunt Geoffrey , Siebrasse Erica A.
Published: November 2023

Academic institutions, professional societies and federal agencies recently have been exploring ways to improve career development for biomedical graduate students and postdoctoral fellows. While many types of career resources are available, there has not been much research into what strategies are most effective. The American Society for Biochemistry and Molecular Biology piloted a regional two‐day career‐development workshop for graduate students and postdoctoral fellows in July 2016. The workshop's learning goals were as follows: Participants will (1) learn about careers open to Ph.D.s; (2) improve their networking skills; (3) develop career goals and a preliminary plan for achieving those goals; and (4) improve their application materials, professional communication and interview skills. To evaluate the workshop outcomes, participants were requested to complete pre‐ and post‐workshop evaluations, which we administered electronically using Survey Monkey software. We also assessed participants' views on the availability of career resources, salary and career prospects through these evaluations. Seventy people attended the workshop, of which 64 percent were graduate students and 30 percent were postdoctoral fellows. Evaluation response rates were high, with 43 participants (61 percent) completing the pre‐evaluation and 39 participants (56 percent) completing the post‐evaluation. More than 75 percent of respondents rated the workshop as being very effective or effective for all of the outcomes queried, which corresponded to the aforementioned four learning goals. Descriptive statistics showed statistically significant differences in several pre‐ and post‐workshop attitudes and knowledge. Respondents showed increased confidence in abilities to build professional networks (p=.07), increased positive responses to having a career plan they feel confident about (p=.03), and increased confidence in having sufficient professional development resources available outside their institutions (p=.08). Based on this data, we propose that this economical, regional workshop model is an effective strategy for facilitating thoughtful and purposeful individual career development planning for graduate students and postdoctoral fellows. The ASBMB will be continuing the workshop series in 2017.

Support or Funding Information

The American Society for Biochemistry and Molecular Biology funded this project.
MAMS – A Biochemistry and Molecular Biology Rich Bridge Program to Health Professional School
Authors: Taylor Mark A
Published: November 2023

The Master of Arts in Medical Sciences (MAMS) degree at Heritage University, a predominantly Native American and Hispanic‐serving institution, is a one year bridge or pipeline program to graduate health professional schools. MAMS students are typically first generation, minority, late‐blooming, or disadvantaged individuals. Coursework taken alongside first‐year medical students at Pacific Northwest University of Health Sciences as well as first‐year pharmacy students at Washington State University coupled with standardized exam preparation, service‐learning opportunities, and access to medical school faculty/staff provide MAMS students with the capability to strengthen their applications as well as demonstrate their readiness for professional school. The curriculum is biochemistry rich and focuses on the molecular basis of health and disease. Nearly one half of the coursework is biochemistry and molecular biology in nature covering topics such as histology, immunology, embryology, microbiology, biochemical metabolism, genetics, pharmacogenomics, medical physiology, and research theory. Additional instruction is provided in medical skills and the psychosocial basis of disease and treatment. Delivery of course content utilizes lectures, in‐class discussion, case‐based learning, small‐group learning, computer‐facilitated learning, and laboratory activities to maximize student comprehension of fundamental basic science principles. Since the program's inception in 2012, 100% of students have graduated, 40% of students have been minorities, over 90% of graduates have gained admission into a health professional school of their choice, and 100% of MAMS students in professional schools have remained in good academic standing. MAMS students have been admitted to medical, dental, optometry, pharmacy, podiatry, and physician assistant schools. MAMS students admitted to professional schools have achieved equivalent or superior class grades and board scores compared to other admitted students. Overall student satisfaction is running 90.8%.

Support or Funding Information

Private Institutional
Integrating Research Experiences into Introductory Biology Laboratories to Engage Undergraduate Students in STEM Learning
Authors: Zies Deborah , Stebar Michael , Baker Dianne
Published: November 2023

The Biology Department at the University of Mary Washington has been implementing changes in our curriculum to meet the recommendations of Vision and Change. One aspect of this process is to include authentic research experiences in the introductory biology laboratory. Significant evidence suggests that incorporating research experiences into introductory biology courses can improve student learning, their understanding of the research process, and their interest in their biology course. We developed three new laboratory modules, each of which is based upon a short research project. All students in our sections of introductory biology completed the three modules during the first 8 weeks of the semester. In the second 8 weeks, they carried out the laboratories traditionally performed in the introductory course. We are currently evaluating the effectiveness of the new lab modules in producing student gains in content knowledge, understanding of the research process, and attitudes toward science. To assess student content knowledge and understanding of the research process, we gave pre‐ and post‐tests for each new module and before and after the traditional introductory laboratories. To assess students' perceptions of their understanding of the scientific process and their attitude toward science, students completed surveys at the beginning and end of the semester. We will present analysis of these assessment instruments.
Scientific Community Outreach in Central Texas
Authors: Bondoc Joshua Anthony , Ream Jennifer
Published: November 2023

The Texas State ASBMB student chapter includes both undergraduate and graduate students. We collaborate with several other student organizations to develop and carry out a wide variety of science outreach events for elementary and junior high students in Central Texas. One of our primary goals for our outreach events is to engage both students and their families in fun, hands‐ on STEM experiences. Our events are substantially interdisciplinary, and include a variety of STEM topics in addition to the biological sciences. For example, we incorporate concepts like density and mass to draw connections between mathematics and physics and their practical applications. These accessible experiments help the community at large engage and develop critical thinking and reasoning skills. Texas State students derive significant benefit from these events, too, as these opportunities enable our student chapter members to utilize their science education as an instrument to connect with their community while encouraging young minds to engage in learning outside of the classroom environment. As a Hispanic‐serving institution, our student demographic parallels that of the Central Texas community. Youth participants interact with a diverse array of college students, who serve as role models to support an inclusive STEM learning environment. Finally, we have found increased student participation and stronger impact in our community when we collaborate and coordinate with other student scientific organizations, including the Texas State student chapter of the American Chemical Society.
The Evolution of Hemocyanin
Authors: Schuld Molly , Bhatia Rohit , Bobber Summer , Dorava Benjamin , Fragoso Brandon , Johanneck Olivia , Ledger Kiley , Haralson Brenden Mclaughlin , Mitchell Alex , Perez Jonathan , Rivera Tiffany , Ruiz Julian , Sheikh Samia , Ya Ahyu , Perez Jose
Published: November 2023

Hemocyanin is the oxygen‐carrying protein in most mollusks and some arthropods. It is relevant to the study of natural selection as it evolved after hemoglobin. How do environmental factors affect the structure and the oxygen affinity of hemoglobin compared to the structure and the oxygen affinity of hemocyanin?

The Ronald Reagan High School MAPS Team used 3‐D modeling and printing technology to examine the structural differences that affect oxygen affinity of hemocyanin and hemoglobin under various environmental conditions. Specifically, research was focused on hemocyanin of Limulus polyphemus (Atlantic horseshoe crab) and hemoglobin of Scapharca inaequivalvis (Ark clam). Temperature affects the affinity of both hemocyanin and hemoglobin for oxygen. The partial pressure of CO2, pH, the concentration of 2,3‐DPG, and the presence of unusual hemoglobin species, and temperature are all physiological factors that may influence the oxygen affinity of hemoglobin and hemocyanin.

The study of evolution of a particular protein is important to our understanding of its function. By studying the variations that were selected for in hemocyanin as it evolved from hemoglobin through comparison of both protein structures, a better grasp of the evolutionary process can be developed. In an ongoing scientific study, hemocyanin is being extracted from species and being inserted into other species that utilize hemoglobin, testing the potential benefits of hemocyanin. Our protein story and physical models defining the similarities and differences in hemoglobin and hemocyanin structure offer insight into their similar, but unique, functions.

Support or Funding Information

The MAPS program is supported by the Center for BioMolecular Modeling at the Milwaukee School of Engineering.
Use of a protein scavenger hunt as a review activity in an upper‐division biochemistry course
Authors: Mann Francis M
Published: November 2023

The composition, structure, and folding of proteins is a common topic in upper‐division biochemistry courses. In this 65 student course, student learning objectives include recognizing and reciting amino acids by structure and abbreviation, predicting structural changes due to pH, formation of secondary structures, and folding peptides into tertiary and quaternary structures. In order to review and self‐assess learning prior to an exam, students worked in groups to analyze clues in a four‐tiered scavenger hunt. Tier one consisted of locational clues written in single letter amino acid code leading to commonly recognizable campus locations. Tier two consisted of calculation of net charge on a small peptide in order to unlock a clue directing them to the next location. Tier three asked the students to decode a locational code by folding aligning a primary sequence on a secondary structure. The final tier asked students to fold peptide sequences into a quaternary structure with a specific motif and return to their instructor with the completed model. Common errors in deciphering of clues routed students back to their instructor early for group tutoring and concept correction prior to continuing on the hunt. Post‐activity student evaluation indicated students agreed that this activity helped them practice their amino acid recognition (73.4%), identify holes in their knowledge (81.4%), and the activity was better than attending a review lecture (82.2%). Overall, this activity serves as an engaging method for reviewing topics associated with protein structure.
Adaptation of Conceptual Frameworks from Public Health to Promote Deeper Learning in a Biochemistry Lab Course Curriculum
Authors: Smith‐Keiling Beverly
Published: November 2023

The classroom is an ecological system encompassing biological factors of health, mental health, learning and behavior constructs, and outcomes in learning, retention, critical thinking, adaptation to stress, conflict resolution in team partnerships within the community, and spanning different levels in the community. Individual, interpersonal and community determinants interact on micro‐levels with lab partners, to mezzo‐levels in a group of four, a larger lab bench, a lab classroom, and the macro‐level lecture classroom to impact learning of biochemical skills, transfer of knowledge from prior courses, and confidence in ability to perform lab skills. Because a healthy ecosystem in the classroom leads to healthy support of learning, the aim of this analysis was to examine the main theories and conceptual frameworks in the field of Public Health, and adapt major constructs that impact learning to develop a conceptual framework that provides structure for addressing different needs in a curriculum to promote learning. To refine which constructs would be most applicable to students in a biochemistry lab course, a series of skill‐based; confidence/self‐efficacy; attitudinal: motivation based on getting good grades, learning new information, or discovery; social peer data in study groups; and demographic assessments were administered in a course n=92 divided into six lab sections over a semester.

Based on student responses, the following conceptual frameworks contained constructs that related both to health and student learning: Health Behavior Model (HBM) with perceived barriers, benefits, and self‐efficacy; Theory of Reasoned Action (TRA) and Theory of Planned Behavior (TPB) combined into the Integrated Behavior Model (IBM) with experiential attitudes, perceived control, self‐efficacy and intention to perform; Transactional Model of Stress and Coping with problem‐focused, emotion‐focused and meaning‐based coping including constructs of control, self‐efficacy, and motivational relevance; and major constructs of the Social Cognitive Theory (SCT) involving cognitive, environmental and behavioral influences on behavior such as collective efficacy, observational learning, social support and knowledge, all within the context of the Social Ecological Model (SEM) individual inner‐level determinants, and outer‐level determinants of interpersonal, institutional, and community. Thus, the resulting conceptual framework devised from these foundations of Public Health provides a new mechanism to design curricula that promote self‐actualized learning through behavioral change. Finally, the PRECEDE‐PROCEED and Intervention Mapping Models are further integrated providing structure for the next step of implementing an inquiry‐based intervention into a current cookbook‐style biochemistry laboratory to design and test adaptive student outcomes measured in the context of this framework.
The Role of Skill Assessments in an Undergraduate Non‐Majors Biochemistry Lab Course
Authors: Hart Orla M
Published: November 2023

Non‐majors lab courses tend to enroll students of varying skill and engagement levels, and students often find it challenging to focus both on the goals and principles of their experiments, as well as the development of lab skills. Practical skills assessments are time consuming to implement, and can be stressful to students, which can impact their performance in the course. However, precision and accuracy in lab skills leads to more reliable experimental data, which was hypothesized would increase student engagement and overall knowledge gains in addition to development of core competencies.

This study investigated the improvement in basic lab skills, including liquid handling, data handling, time‐management, in a non‐majors biochemistry lab course following the implementation of formal practical skills assessments as part of the overall course grade. Low‐stakes, relatively simple assessments were implemented as part of midterm and final exams, to minimize students' anxiety at taking a practical exam and minimize additional study/practice time required. Students had the opportunity to practice the specific skills several times throughout their regular coursework, and were provided with benchmarks against which they could measure their own skill competencies. Implementation of these skill assessments resulted in dramatic improvements in the quality of student's experimental data throughout the lab course, which likely also contributed to increases observed in overall knowledge gains. In addition, students gained more confidence in their own skills and their ability to implement those skills in other labs.