bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hepatocyte‐specific depletion of augmenter of liver regeneration (ALR) protein alters miRNA signature linked to lipid homeostasis leading to excessive steatosis
Authors: Kumar Sudhir , Rani Richa , Karns Rebekah , Sharma Bal Krishan , Gandhi Chandrashekhar R. 
Published: June 2021

Augmenter of liver regeneration (ALR) is a fundamental life protein expressed in all mammalian organs. ALR's presence in mitochondria is essential for their function and survival. Depletion of ALR from liver (hepatocyte)‐specific ALRflox/flox/Alb‐Cre (ALR‐L‐KO) mice causes mitochondrial injury, robust lipid accumulation and apoptosis between 1 and 2 weeks post‐birth. Steatosis is regressed upon reappearance of ALR by 4 weeks but continued death of Cre‐expressing hepatocytes induces regeneration, inflammation and fibrosis. To delineate mechanisms of this pathological progression, we investigated whether ALR depletion alters expression of micro‐RNAs (miRNAs), which play important roles in numerous biological processes including lipid homeostasis. We performed miRNA‐seq analysis and profiled the hepatic miRNA expression in 1‐, 2‐, and 4‐week old mice. Of the 765 micro‐RNAs identified in WT and ALR‐L‐KO livers, 203 showed differential expression: 125, 106 and 141 miRNAs were up‐regulated and 70, 97 and 61 miRNAs down‐regulated at 1, 2 and 4 weeks respectively in ALR‐L‐KO compared to the WT mice. miR‐708‐3p, miR‐540‐3p and miR‐541‐5p, which have 3′UTR‐binding sites for peroxisome proliferator‐activated receptor (PPAR)α, carnitine palmitoyl transferase a (CPT1a) and mitochondrial transcription factor A (TFAM) (all down‐regulated at 2 weeks in ALR‐L‐KO mice), were all found to be up‐regulated at 2 weeks in ALR‐L‐KO compared to the WT mice. Increase in these miRNAs upon ALR depletion was also concurrent with increased expression of elongation of very long fatty acids 6 (ELOVl6) and steroyl CoA desaturase (SCD1) that are involved in de novo lipogenesis, and decreased expression of acyl CoA oxidase 1 (ACOX1) and CPT1 that promote β‐oxidation of fatty acids. The effect of ALR depletion on these miRNAs was recapitulated in vitro in cultured hepatocytes. Likewise, hepatic expression of miRNAs implicated in inflammation and fibrosis (miR‐199a‐1‐5p, miR‐146b‐5p, miR‐194‐1‐5p, miR‐1843a, miR‐410‐3p and miR‐434‐3p) was also altered in a way to promote these pathologies. These findings suggest that ALR's regulation of miRNAs is critical to hepatic lipid homeostasis with potential implications in nonalcoholic fatty liver disease/steatohepatitis.Support or Funding InformationThis work was supported by DoD grant W81XWH‐14‐PRMRP‐IIRA and NIH R21 AA020846 to CRG.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Anatomical and functional landscapes of hair regeneration across the body
Authors: Plikus Maksim , Wang Qixuan , Oh Ji Won , Nie Qing 
Published: June 2021

Hair follicles (HFs) in the skin show robust cyclic regeneration. Yet, since skin contains many thousands of HFs, control principles of collective hair regeneration and hair growth regionalization remain unclear. Using multi‐scale mathematical modeling we shows that coupling inhibitor and activator signals with physical growth of HFs is sufficient to drive periodicity and excitability of hair regeneration. Model simulations and experimental data reveal that the entire skin in mice behaves as a heterogeneous regenerative landscape, composed of anatomical domains where HFs have distinct cycling dynamics. Interactions between fast‐cycling ventral and chin HFs and slow‐cycling dorsal HFs produce prominent bilaterally symmetric patterns. Skin on mouse ears behaves as a hyper‐refractory domain with HFs that remain, in principle, competent to cyclic regeneration, yet that physiologically enter extended rest phase. Ear HF hyper‐refractivity relates to high levels of BMP ligands and WNT antagonists, in part expressed by ear‐specific cartilage and muscle, the novel component of skin signaling macro‐environment. Hair growth stops at the boundaries with hyper‐refractory ears and anatomically discontinuous eyelids, generating wave‐breaking effects. We posit that similar mechanisms for coupled regeneration and large‐scale patterning of growth activities with dominant activator, hyper‐refractory, and wave‐breaker regions can operate in other actively renewing organs.Support or Funding InformationMVP is supported by the NIH NIAMS grants R01‐AR067273, R01‐AR069653 and Pew Charitable Trust grant. QN is supported by NSF grants: DMS 1161621, and DMS 1562176 and NIH grants: P50‐GM076516, R01‐GM107264, and R01‐NS095355. JWO is supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (2016R1C1B1015211).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
TRPV4 channels regulates matrix stiffness and TGFβ1‐induced epithelial‐mesenchymal transition
Authors: Rahaman Shaik O. , Sharma Shweta , Goswami Rishov 
Published: June 2021

Epithelial‐mesenchymal transition (EMT) has important functions in cellular processes including development, wound healing, oncogenesis, and fibrosis. Emerging data support a role for both a mechanical signal, and a biochemical signal, e.g., transforming growth factor β1 (TGFβ1), in EMT. Here, we report evidence showing that transient receptor potential vanilloid 4 (TRPV4), calcium‐permeable channel and member of TRP superfamily, is the likely mediator of EMT in response to both TGFβ1 and matrix stiffness. Specifically, we found that: i) genetic ablation of TRPV4 blocked TGFβ1‐induced EMT in normal mouse primary epidermal keratinocytes (NMEKs) as determined by changes in morphology and alterations of expression of EMT markers including E‐cadherin (ECAD), N‐cadherin (NCAD), and α‐smooth muscle actin (α‐SMA), and ii) TRPV4 deficiency prevented matrix stiffness‐induced EMT in NMEKs over a pathophysiological range. Intriguingly, TRPV4 deletion in mice suppressed expression of mesenchymal markers, NCAD and α‐SMA, in a bleomycin‐induced murine skin fibrosis model. We found an increased co‐localization of TRPV4 with NCAD, and decreased co‐localization of TRPV4 with epithelial marker ECAD in skin tissues of bleomycin‐treated wild‐type mice compared to saline controls. Mechanistically, we found that: i) TRPV4 was essential for the nuclear translocation of YAP/TAZ (Yes‐associated protein/transcriptional coactivator with PDZ‐binding motif) in response to matrix stiffness and TGFβ1, ii) TRPV4 deletion inhibited both matrix stiffness‐ and TGFβ1‐induced expression of YAP/TAZ proteins, and iii) TRPV4 deletion abrogated both matrix stiffness‐ and TGFβ1‐induced activation of AKT, but not Smad2/3, suggesting a mechanism by which TRPV4 activity regulates EMT in NMEKs. Altogether, these data identify a novel role for TRPV4 in regulating EMT, and thus suggest that therapeutic targeting of TRPV4 may provide a selective approach to ameliorate the development of skin fibrosis and oncogenesis.Support or Funding InformationAHA (13SDG17310007), Startup grant from University of Maryland, NIH (1R01EB024556‐01), and NSF (CMMI‐1662776) grants to SOR.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cell cycle re‐entry from quiescence promotes genome instability
Authors: Matson Jacob P. , Limas Juanita , Perez Joanna , Kedziora Kasia , Cook Jeannette G. 
Published: June 2021

Animal cells transition between periods of active cell division cycles and periods of quiescence without cell division. Prior to cell division, DNA replication initiates at thousands of origins across the genome during S phase of every cell cycle. Each origin that initiates must have been licensed for replication in the preceding G1 phase by the regulated loading of Minichromosome maintenance (MCM) complexes onto DNA. Cells with insufficient MCM loading are underlicensed, risk incomplete replication, and are hypersensitive to replication stress and DNA damage. Licensing is tightly restricted to G1 phase, but the length of G1 varies. How mammalian cells ensure sufficient licensing in cells with either long or short G1 phases is still poorly understood. We recently reported that cycling cells with naturally short G1 phases license origins faster than cells with long G1s and that the fast loading is important for a short G1. The first G1 phase of cells re‐entering the cell cycle from quiescence is longer than G1 phase in actively cycling cells. We hypothesized that the differences in G1 length during cell cycle re‐entry and G1 length in dividing cells will result in differences in the amount or rate of origin licensing in the different G1 phases. We used single cell flow cytometry and live cell imaging to explore the relationships among cell cycle re‐entry, G1 length, origin licensing, and the activity of the family of cyclin‐dependent kinases that drive the G1‐to‐S phase transition in untransformed human cells. Despite the extra time in G1 phase, cells re‐entering the cell cycle are significantly underlicensed in the first cell cycle but not the second or subsequent cell cycles. Moreover, cells in the first S phase are hypersensitive to replication stress. Thus, G1 phase upon cell cycle re‐entry is characterized by slow (or delayed) origin licensing combined with S phase entry before all cells are fully licensed. Overproducing cyclin E or cyclin A can uncouple G1 length from origin licensing by driving premature S phase entry. We predict that the normal coupling of origin licensing and Cdk2 activation is weaker at the first G1/S transition. Cells re‐entering the cell cycle from quiescence have increased levels of Cdk inhibitor proteins which may contribute to the uncoupling of licensing timing or speed and S phase entry. The transition from quiescence to active division is a particularly sensitive time for DNA damage and the number of transitions into and out of quiescence may play a role in long term cell viability and genome stability.Support or Funding InformationThis work was supported by a fellowship from the NSF (DGE‐1144081) to J.P.M and by the NIH to J.G.C. (GM083024 and GM102413). Additional funding was provided by the W.M. Keck Foundation.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Blocking protein myristoylation inhibits prostate cancer progression
Authors: Cai Houjian , Kim Sungjin , Alsaidan Omar Awad 
Published: June 2021

Objective of the studyProtein N‐myristoylation enables localization to membranes and helps maintain protein conformation and function. N‐myristoyltransferases (NMT) catalyze co‐ or post‐translational myristoylation of Src family kinases and other oncogenic proteins, thereby regulating their function. The goal of this study is 1) to demonstrate that N‐myristoylation is essential for the tumorigenic potential of oncogenioc proteins such as Src kinase; 2) to identify novel lead compounds to inhibit the NMT enzymatic functions; 3) to demonstrate that the compound exhibits its inhibitory function on cancer progression.Statement of MethodsNMT1/2 proteins were purified for the evaluation of their enzymatic functions. The proteins were further crystalized for study their structure. The myristoylation of Src kinase was detected by Click chemistry. Protein fractionation was evaluated by immunoblotting. A low throughput screening was performed to identify an myristoyl‐CoA analog to inhibit NMT enzymatic function. TCGA database was used for the analysis of the expression correlation. Additionally, inhibition of cell proliferation, migration, invasion assays and cell cycle analysis were analyzed in numerous cancer cells. Prostate regeneration assay and xenograft tumor models were applied for in vivo studies.Summary of the resultsWe provide genetic and pharmacological evidence that inhibiting the N‐myristoyltransferase NMT1 suppresses cell cycle progression, proliferation and malignant growth of prostate cancer cells. Loss of myristoylation abolished the tumorigenic potential of Src and its synergy with androgen receptor in mediating tumor invasion. We identified the myristoyl‐CoA analog B13 as a small molecule inhibitor of NMT1 enzymatic activity. B13 exposure blocked Src myristoylation and Src localizaiton to the cytoplasmic membrane, attenuating Srcmediated oncogenic signaling. B13 exerted its antiinvasive and antitumor effects against prostate cancer cells with minimal toxic side‐effects in vivo. Structural optimization based on structure‐activity relationships enabled the chemical synthesis of LCL204 with enhanced inhibitory potency against NMT1.ConclusionOur study demonstrates that B13, a myristoyl‐CoA analog, inhibits NMT enzymatic functions and Src mediated tumorigenesis. Our results offer a preclincal proof of concept for the use of protein myristoylation inhibitors as a strategy to block prostate cancer progression.Support or Funding InformationNIH (R01CA172495) and DOD (W81XWH‐15‐1‐0507)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hepatocyte growth factor receptor (HGFR) as a potential lung cancer target
Authors: Ahmed Haidar , Skouta Rachid 
Published: June 2021

Lung cancer is the leading cause of cancer‐related death in the world affecting both sexes, with more than 222,500 new cases each year in the U.S, and poor survival rate. Due to low efficacy of current therapies, recent studies are focusing on discovering new targets that generates better and more effective therapies. While most of the current drugs target the epidermal growth factor receptor (EGFR) and KRAS, other targets have not been very well studied. c‐Met, also known as tyrosine‐protein kinase Met or hepatocyte growth factor receptor (HGFR), belonging to the tyrosine kinase family play a major role in signaling transduction pathways and has been a potential target of lung cancer. For this reason, kinase receptors have been the target of many modern drugs. In solid tumors, such as lung cancer, upregulation of c‐Met occurs as mechanism to promote proliferation, survival, metastasis and angiogenesis. Here, we present a low cost drug discovery approach to identify a novel effective inhibitor of c‐Met using structure based virtual screening (SBVS). We obtained c‐Met top crystal structures from the Protein Data Bank (PDB ID: 3BUX, 3F66, 3ZCL, 3DKC, 4R1V). Potential binding site were screened using Schrodinger software package to generate receptor grids. Using the obtained receptor grids a drug library was docked using Glide. After this docking results were compared by the free energy of binding. Using Phase e‐pharmacophore and “create consensus” top ligands were further screened to understand ligand‐protein interaction to improve efficacy of drug. Future directions is to adapt top compound to in vitro.Support or Funding InformationThis lab is supported in part by the USDA‐NIFA‐HSI grant 2012‐38422‐19910 and NIH Grant #5G12MD007592 from the National Center for Research Resources to the UTEP Border Biomedical Research Center. And by the Lung Cancer Research Foundation.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Localization of the Mutant SepG1 Protein to Sites of Cell Division in the Filamentous Fungus Aspergillus nidulans
Authors: Ugwu Uchenna , Jackson‐Hayes Loretta , Hill Terry William 
Published: June 2021

Cell division (cytokinesis) in filamentous fungi involves inward growth of the plasma membrane at sites of crosswall (septum) formation, under the guidance of a contractile actomyosin ring (CAR). The process involves the coordinated activities of multiple proteins, most of which are poorly characterized or wholly undiscovered. A forward‐genetics approach to identifying proteins with unrecognized roles in cell division has been to artificially mutagenize cells and isolate viable progeny defective in septum formation (septation), followed by identification of mutation sites at the molecular level. Prior work in this laboratory has localized a classic temperature‐sensitive septation mutation, termed sepG1, in the model fungus Aspergillus nidulans to a gene locus predicted to encode an IQGAP homologue. Reduced expression of the wild type gene under the regulatable AlcA promoter blocks septation, and a GFP‐tagged version of the wild type protein localizes to sites where septa are forming. We have also succeeded in GFP‐tagging the protein encoded by the mutant sepG1 allele and have demonstrated that it too localizes to septation sites, even under restrictive conditions that prevent completion of septation, indicating that the sepG1 defect is not in protein targeting. Multiple attempts using Mendelian methods to create double‐mutant strains expressing both GFP‐tagged SepG1 protein plus RFP‐tagged versions of actin or myosin have not been successful, preventing investigation of whether the SepG1 protein associates normally with the CAR. Therefore, we have generated riboflavin‐auxotrophic strains containing untagged sepG1 mutant alleles along with RFP‐tagged wild‐type alleles of actin or myosin, with the goal of tagging the sepG1 allele in these strains via direct genetic transformation. We have constructed a plasmid‐based cassette containing sequences that, after integration, will allow the simultaneous expression of GFP‐tagged SepG1 protein in the same strains that are also expressing RFP‐tagged actin or myosin.Support or Funding InformationNational Science Foundation Grant 1615192 (Loretta Jackson‐Hayes, PI).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Undergraduate biology students view scientific models as easy‐to‐learn simple explanations
Authors: Trujillo Caleb , Bennett Steve , Long Tammy 
Published: June 2021

The inclusion of modeling in undergraduate science classrooms is warranted so that students engage in authentic scientific practices to understand the world. This study investigates students' perceptions of modeling by asking: what attributes do introductory biology students associate with scientific models? We conducted an exploratory mixed methods study with participants recruited from model‐based introductory biology courses across two interviews. During the first interview, students provided attributes of models including definitions, purposes, and qualities. An inductive analysis revealed that most students viewed models as explanatory visual representations that aid learning. During the second interview one year later, the same students assigned identified attributes to different representations in a sorting task. A correspondence analysis revealed that learners closely associate scientific models to simplistic easy‐to‐learn explanations, but not to data or predictions. The results suggest that students associate scientific models with explanations that aid learning by making complex content simple and comprehensible. Conversely, students perceive the attributes of empirical support and predictive power as distinct from scientific models. This study furthers an understanding of students' perspectives of models in a biology classroom and informs potential changes to model‐based instruction.Support or Funding InformationThis material is based upon work supported by the National Science Foundation under Grant No. DRL 1420492.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
S‐Succinylcysteine Breakdown – How Bacillus subtilis Utilizes an Inevitable Product of Metabolite Damage
Authors: Niehaus Thomas Daniel , Folz Jacob , McCarty Donald R. , de Crécy‐Lagard Valérie , Moraga David , Fiehn Oliver , Hanson Andrew D. 
Published: June 2021

Cellular thiols such as cysteine and glutathione spontaneously and readily react with the respiratory intermediate fumarate to form stable S‐succinyl adducts. Succination of thiols by fumarate increases in certain tumors and in response to glucotoxicity associated with diabetes, thus S‐succinyl adducts such as S‐succinylcysteine (SSC) are considered to be on cometabolites and biomarkers for human disease. No plausible disposal routes for S‐succinyl compounds have been demonstrated. Here, we show that Bacillus subtilis has a pathway to metabolize SSC to cysteine and that this pathway is encoded by the yxe operon. The first pathway step is N‐acetylation mediated by the yxeL gene product, most probably follow‐ed by oxygenation and elimination of oxaloacetate to yield N‐acetylcysteine, which is then deacetyl‐at‐ed. In support of this breakdown pathway, knockouts of the predicted B. subtilis genes involved in each catabolic step of SSC breakdown lose the ability to grow on SSC as a sulfur source and accumulate the predicted upstream metabolite(s). We further show that N‐acetylation reduces SSC toxicity. SSC disposal substantiates the emerging concept that cells often handle toxic metabolites by pathways that begin with acetylation and end with deacetylation, in direct analogy to the blocking‐deblocking strategies used in organic chemistry.Support or Funding InformationThis work was supported by U.S. National Science Foundation grant MCB‐1153413 and by an endowment from the C.V. Griffin Sr Foundation.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.