bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intestinal Mucosa Pro‐Repair Properties of Macrophage Derived IL‐10 are Mediated by CREB Triggered Epithelial WISP‐1 Signaling
Authors: Quiros Miguel , Nishio Hikaru , Neumann Philipp A , Leoni Giovanna , Garcia‐Hernandez Vicky , Siuda Dorothee , Feng Mingli , Bernal Gabriela , Hilgarth Roland , Williams Holly , Brazil Jennifer C , Dedhia Priya H , Spence Jason , Parkos Charles A , Denning Timothy L , Nusrat Asma 
Published: November 2023

In response to injury, epithelial cells migrate and proliferate to cover denuded mucosal surfaces and repair the barrier defect. This process is orchestrated by a dynamic cross‐talk between immune cells and the epithelium. However, the underlying mechanisms of repair remain incompletely understood. Here, we report that increased generation of IL‐10 in healing wounds orchestrates repair of the intestinal mucosal barrier. Conditional deletion of IL‐10 specifically in CD11c‐expressing cells in‐vivo identified macrophages as a critical innate immune contributor to IL‐10‐mediated mucosal wound repair. Consistent with these findings, wound closure in Rag1 KO mice was unimpaired, suggesting that adaptive immune cells do not influence intestinal mucosal wound repair. Furthermore, following mucosal injury, macrophage‐derived IL‐10 resulted in epithelial cAMP response element‐binding protein (CREB) activation and subsequent synthesis and secretion of the pro‐repair WNT1‐inducible signaling protein 1 (WISP‐1). WISP‐1 promoted epithelial proliferation and wound closure by activation of epithelial beta catenin and cyclin D1. These findings identify an important role of macrophages derived IL‐10 that cross‐talks with epithelial WISP‐1 signaling to orchestrate mucosal repair.Support or Funding InformationThis work was supported by NIH grants (RO1DK055679, RO1DK089763 to A. Nusrat; R01DK097256 to T. Denning; and DK61739, DK72564 and DK79392 to C.A. Parkos); the Crohn's and Colitis Foundation of America Research Fellowship Award (326912) to M. Quiros
Desmoglein 2 Regulates the Intestinal Epithelial Barrier via p38 Mitogen‐Activated Protein Kinase
Authors: Ungewiß Hanna , Vielmuth Franziska , Suzuki Shintaro T. , Maiser Anderas , Harz Hartmann , Leonhardt Heinrich , Kugelmann Daniela , Schlegel Nicolas , Waschke Jens 
Published: November 2023

Intestinal epithelial barrier properties are maintained by a junctional complex consisting of tight junctions (TJ), adherens junctions (AJ) and desmosomes. Desmoglein 2 (Dsg2), an adhesion molecule of desmosomes, is required for epithelial barrier properties and may contribute to barrier defects in Crohn's disease. Here, for the first time we identified extra desmosomal Dsg2 on the surface of differentiated enterocytes displaying junctional complexes by Triton extraction, confocal microscopy, SIM and STED. Atomic force microscopy (AFM) revealed Dsg2‐specific binding events on the surface of enterocytes with a mean unbinding force of around 30 pN which were more prominent close to cell borders. Furthermore, we demonstrated that inhibition of Dsg2 binding induced activation of p38 mitogen‐activated protein kinase (p38MAPK) which is a key regulator of desmosomal adhesion. An inhibitory Dsg2 antibody activated p38MAPK, under conditions where it significantly reduced cell cohesion in a dissociation assay and Dsg2‐specific binding in AFM. Loss of Dsg2 in enterocytes led to reduced p38MAPK activity accompanied with loss of barrier integrity and impaired barrier reformation. Dsc2 rescue in Dsg2/Dsc2 deficient enterocytes did not restore p‐p38MAPK levels indicating, that Dsg2 regulates the activity of this kinase. Direct activation of p38MAPK in Dsg2 knockout cells enhanced barrier reformation demonstrating that Dsg2‐mediated activation of p38MAPK is crucial for barrier function. Collectively, our data show that Dsg2, in addition to its adhesion function, regulates intestinal barrier function via p38MAPK signaling.Support or Funding InformationThis work was supported by the DFG priority program SPP 1782
Epigenetic re‐programming of breast cancer by pharmacological targeting of C‐terminal binding protein
Authors: Byun Jung S , Gardner Kevin L 
Published: November 2023

The C‐terminal binding protein (CtBP) is a family of dimeric nuclear proteins whose levels are increased in cancers of the colon, ovaries, prostate and breast. Elevated CtBP protein expression is associated with poor cancer survival, thus implicating CtBP as both a biomarker and a promising candidate for therapeutic intervention. As a dimer, CtBP provides a scaffold that couples multiple different DNA‐binding transcriptional regulators with a variety of chromatin modifying protein complexes to alter the epigenetic landscape throughout the nucleus. These properties provide the rationale for pharmacological targeting of CtBP to alter or epigenetically change regulated gene expression in cancer cells. In this study, we employ computer assisted drug design to screen for optimal quantitative structure‐activity relationships (QSARs) between small molecules and CtBP to identify 24 potential CtBP inhibitors. Functional screening of these compounds identifies 4 lead compounds with low toxicity and high water solubility. Treatment of breast cancer cells at micro‐molar concentrations of these small molecular inhibitors induces significant de‐repression of epigenetically silenced pro‐epithelial genes in the mesenchymal, triple negative breast cancer cell line, MDA‐MB‐231. This re‐activation is associated with eviction of CtBP from the respective gene promoters, disrupted recruitment of CtBP‐chromatin modifying protein complexes, increased deposition of activating epigenetic histone marks, and upregulation of both pro‐epithelial gene mRNA and protein expression. In functional assays, CtBP inhibition by these small molecular inhibitors decreases cellular invasion, and improves DNA repair.FRET (Förster resonance energy transfer) analysis demonstrates that CTBP inhibition results in decreased FRET intensity, suggesting the CTBP dimerization interaction is repressed by CTBP inhibition. In addition, pharmacological inhibition of CtBP combines with established epigenetically targeted drugs to synergistically decrease cell migration and potentiate the reactivation of silenced pro‐epithelial gene expression in triple negative cancer cells. Finally, CTBP inhibition results in transcriptional repression of MDR1 expression and reduces the population of Doxorubicin resistant cells in triple negative breast cancer cell lines.These findings implicate the possible use of this compound in strategies for therapeutic intervention that may increase the efficacy and decrease the acquired resistance to targeted therapeutic intervention in breast cancer.
DNA Methylation, Hydroxymethylation and Formylation in Human Frontal Cortex of Autistic and Schizophrenic Subjects
Authors: Trivedi Malav , Deth Richard , Zhang Yiting , Abdolmaleky Hamid 
Published: November 2023

Epigenetic regulation provides a molecular mechanism for long‐lasting, activity‐dependent changes in gene expression. In the brain, increased neuronal activity can translate into changes in DNA and histone methylation with epigenetic consequences, contributing to neuroplasticity and memory formation. The folate and vitamin B12‐dependent enzyme methionine synthase (MS) controls methylation and is sensitive to redox status, linking aerobic metabolism to epigenetic regulation. In previous postmortem brain studies we showed that MS expression in frontal cortex decreases dramatically with age (500‐fold), while levels of the MS cofactor methylB12 (methylcobalamin; MeCbl) decrease more than 10‐fold across the lifespan. Furthermore, in autistic subjects MS expression and MeCbl levels were significantly lower than age‐matched controls, in association with decreased levels of the methyl donor S‐adenosylmethionine (SAM). MeCbl levels were also decreased in schizophrenia subjects. To determine whether these abnormal metabolic conditions are associated with epigenetic manifestations, we measured global levels of 5‐methylcystosine (5mCyt), 5‐hydroxymethylcytosine (5hmCyt) and 5‐formylcytosine (5fCyt) in DNA from Brodmann areas 10/11 and 44/45 in frontal cortex. Levels of 5mCyt and 5hmCyt were higher in autistic subjects (4–11 yrs) vs. age‐matched subjects (5–13 yrs), while levels of 5fCyt were lower. In schizophrenic subjects (36–49 yrs), levels of 5mCyt were lower than age‐matched controls (36–50 yrs), while levels of 5hmCyt and 5fCyt were higher. A comparison of young vs. middle‐age control subjects revealed significantly lower levels of 5mCyt and 5fCyt, while levels of 5hmCyt were higher in the older subjects. Methylation of specific CpG sites in the D4 dopamine receptor (DRD4) gene were significantly elevated in autism and schizophrenia. These findings confirm that abnormally decreased MS expression and MeCbl levels in frontal cortex of autistic and schizophrenic subjects are associated with differential 5mCyt, 5hmCyt and 5fCyt status, suggesting that epigenetic dysregulation may contribute to neurodevelopmental and neuropsychiatric disorders.Support or Funding InformationNone
A Novel Murine Model of Primary Sclerosing Cholangitis Associated Inflammatory Bowel Disease
Authors: Battista Kayla Danae , Shearn Colin T , Alexeev Erica E , Glover Louise E , Petersen Dennis R , Colgan Sean P , Fennimore Blair P 
Published: November 2023

Primary Sclerosing Cholangitis (PSC) is a progressive cholestatic liver disease characterized by biliary inflammation, fibrosis, and stricturing of the intra and extra‐hepatic bile ducts. Progressive disease leads to recurrent cholangitis, biliary cirrhosis, and increased risk of cholangiocarcinoma. PSC carries a strong association with inflammatory bowel disease (IBD) occurring in approximately 80% of patients. PSC associated IBD (PSC‐IBD) displays a unique phenotype characterized by pan‐colonic distribution, right side predominant inflammation, and increased risk of colorectal cancer compared to non‐PSC IBD. The frequent association and unique phenotype of PSC‐IBD suggests distinctive underlying disease mechanisms from other models of chronic liver disease or IBD alone. Multidrug resistance protein 2 (Mdr2) knockout mice develop spontaneous cholestatic liver injury and fibrosis mirroring human PSC, however there are currently no established PSC‐IBD models of combined cholestatic liver injury and IBD. Though Mdr2−/− mice do not display overt evidence of colonic inflammation at baseline, PCR analysis of whole colon tissue reveals elevated levels of pro‐inflammatory cytokines (KC, TNFα, IL‐1β, and IL‐6). We subjected Mdr2−/− mice to DSS colitis as a novel combined model of PSC‐IBD. In this model, Mdr2−/−/DSS mice display increased disease susceptibility characterized by worsened weight‐loss, decreased colon length, and increased histologic damage in the colon. Additionally, colonic and portal serum levels of pro‐inflammatory cytokines (KC, IL‐6, IL‐1β, and IL‐12p70) were significantly increased as compared to C57BL/6 colitis controls. Baseline elevations in colonic levels of pro‐inflammatory cytokines in Mdr2−/− mice along with increased colitis susceptibility in the Mdr2−/−/DSS model suggests an important role for interdependent signaling pathways originating from liver‐intestine crosstalk mechanisms in mediating intestinal injury in this novel murine model of PSC‐IBD.Support or Funding InformationNIH 095491 and 5R37AA009300‐20 (DRP)
Palmitate Increases Ubiquitination in H4IIE and Primary Rat Hepatocytes
Authors: Stewart Claire M , Estrada Andrea L , Kim Paul Y , Wang Dong , Wei Yuren , Pagliassotti Michael 
Published: November 2023

Saturated fatty acids induce endoplasmic reticulum (ER) stress in liver cells. The presence of ER stress implies that protein processing is impaired. We hypothesized that saturated fatty acid‐induced impairment in protein processing would result in increased ubiquitination and reduced autophagy and proteasome activity.Ubiquitination was assessed by western blot in H4IIE liver cells (n=3) or primary rat hepatocytes (n=3) in the presence of MG132 (5μM), a proteasome inhibitor, palmitate (250μM), a saturated fatty acid, or oleate (250μM), an unsaturated fatty acid, for 6 hours. Proteasome activity was measured in H4IIE liver cells (n=3) using the ZsProsensor‐1, a fluorescent reporter that contains a proteasome degradation domain, in the presence of MG132, palmitate, or oleate for 6 hours. Autophagy was assessed H4IIE liver cells (n=3) by western blot in the presence of palmitate or oleate for 6 hours.MG132 increased ubiquitination by 49% in H4IIE liver cells and primary rat hepatocytes. Palmitate increased ubiquitination by 26% in H4IIE hepatocytes and primary hepatocytes while oleate did not increase ubiquitination. MG132 reduced proteasome activity in H4IIE liver cells by 50% while palmitate or oleate had no significant effect on proteasome activity. Lastly, palmitate or oleate had no effect on autophagy. Overall, these data suggest that the palmitate‐mediated increase in ubiquitination occurred independently of changes in autophagy and the proteasome.Support or Funding InformationNIH: DK072017
Amyloid‐mediated translational control is required for meiosis
Authors: Berchowitz Luke E. , Walker Margaret R. , Kabachinski Gregory L. , Schwartz Thomas U. , Amon Angelika 
Published: November 2023

Amyloids are fibrous protein aggregates that are associated with, and often causative of, numerous human diseases including Alzheimer's, Parkinson's, and diabetes. Amyloids are thought to trigger disease by forming insoluble aggregates composed of inactive protein that interfere with cell viability. Whether and how amyloid properties of proteins participate in cellular functions is poorly understood. We uncoverd a physiological role for amyloids in the regulation of mRNA translation.In budding yeast, repression of translation of the B‐type cyclin CLB3 during meiosis I is essential for establishing the unique meiotic chromosome segregation pattern and for gametogenesis. The meiosis‐specific RNA‐binding protein Rim4 mediates this translational repression. We find that Rim4 forms amyloids, fibrous protein aggregates, and that it is amyloid form of Rim4 that is the active, translationally repressive form of the protein. Our data further show that amyloid formation is a developmentally regulated process. Starvation, one of the signals that triggers gamete development, induces the conversion of monomeric Rim4 into amyloid thereby activating the protein to bring about repression of CLB3 translation. At the onset of meiosis II, Rim4 amyloids are abruptly degraded allowing CLB3 translation to commence. We conclude that proteins can utilize their amyloid‐forming properties to function as central regulators of gametogenesis.Support or Funding InformationHHMI & NIH
Structures and Functions of the Ribosome Quality control Complex or RQC
Authors: Frost Adam 
Published: November 2023

In this talk I will present new structural and functional data concerning the roles and mechanisms of the RQC in cotranslational protein quality control. I will present new cryo‐EM reconstructions and a complete in vitro reconstitution system that sheds new light on how Rqc2 catalyzes the synthesis of Carboxy‐terminal Alanine and Threonine tails or “CAT tails”, and how CAT tailing differs from the canonical chemistry of translation. I will also describe how CAT tail elongation facilitates ubiquitination of failed nascent chains by the E3 ubiquitin ligase, Ltn1, as well as the still poorly characterized RQC component, Rqc1. Our new data demonstrates that CAT tailing by Rqc2 exposes previously inaccessible ubiquitin acceptors to the RING domain of Ltn1 for ubiquitination. CAT tailing, moreover, promotes hydrolytic release of nascent chains from the tRNA molecules in the P‐site of of the 60S subunit, and CAT tails are necessary for nascent chain degradation off certain substrates in vivo.Support or Funding InformationNIH DP2 1DP2GM110772‐01Howard Hughes Medical Institute Faculty Scholar AwardSandler Family Foundation, Program for Breakthrough Biomedical Research
Tuning an endoplasmic reticulum chaperone to the cell's needs
Authors: Ron David 
Published: November 2023

A transcriptional and translational program that strives to match the complement of chaperones in the endoplasmic reticulum (ER) to the burden of unfolded proteins in the early secretory pathway (the Unfolded Protein Response) has long been known to exist and its functional importance has been showcased by genetic and pharmacological manipulations. However, theoretical considerations supported by experimental observations, highlight the latency inherent in this gene expression program and suggest the potential importance of post‐translational adaptations that operate on a shorter time scale. In this talk I shall provide a very brief overview of the Unfolded Protein Response and focus the discussion on some recent observations on an ER‐localized post‐translational circuitry that tunes the activity of the compartment's resident Hsp70 protein, BiP, to rapid fluctuations in unfolded protein load.Support or Funding InformationSupported by a Wellcome Trust Principal Research Fellowship to DR (2008/Z/16/Z) and Wellcome Trust Centre Grant to the CIMR (100140)
Phenobarbital induces ATZ globule clearance in a Mouse Model of Alpha‐1 Antitrypsin Deficiency
Authors: Bell Aaron W , Stoops John , Oertel Michael , Michalopoulos George K 
Published: November 2023

BackgroundAlpha‐1 antitrypsin (α1‐AT) deficiency is the most common genetic cause of pediatric liver disease, which can progress to cirrhosis and hepatocellular carcinoma. Hepatocellular injury is caused by accumulation of the insoluble mutant alpha‐1‐antitrypsin Z (α1‐ATZ) molecule in intracellular globules. Hepatocytes containing these globules (GC) do not proliferate as well as the globule free (GF) hepatocytes in the PiZ (α1‐AT) mouse model. We hypothesized that inducing proliferation by chemical mitogens such as phenobarbital and TCPOBOP would lead to enhanced proliferation of the GF cells that could repopulate the liver and greatly reduce the hepatic stress/damage and/or induce protein clearance mechanisms in GC cells converting them to GF cells.MethodsPiZ mice were administered phenobarbitol (0.1% in drinking water) or TCPOBOP (3mg/kg by gavage) at various times and durations. Liver tissue was analyzed for ATZ globule content, proliferation, as well as gene and protein expression changes.ResultsContinuous or cyclical (1‐week on/1‐week off) administration of phenobarbitol to PiZ mice lead to a significant decrease in ATZ globule content; however, TCPOBOP treatment did not. The size of the ATZ globules was greatly diminished by phenobarbital treatment, indicating likely activation of protein clearance mechanisms that was not seen with TCPOBOP. Ki67 staining showed proliferation in both GC and GF cells with both mitogens. Affymetrix array analysis revealed significant differential gene expression changes in GF and GC cells with and without phenobarbital treatment.ConclusionsProliferation of GF and GC hepatocytes induced by chemical mitogens is not sufficient to induce globule clearance in GC cells. However, phenobarbital induces other changes which results in reduced PiZ globule burden and hepatic toxicity, and may be useful in treating α1‐AT deficiency.Support or Funding InformationNIH/NIDDK Grant Number: P01DK096990 New therapies for liver fibrosis and hyper‐proliferation in alpha 1‐AT deficiency. D. Perlmutter‐PI Project 3: Mechanisms of AT expression and hepatocyte hyper‐proliferation in AT deficiency. G. Michalopoulos, PI and A. Bell, Co‐Investigator
P53 Regulates Progression of Injury and Liver Regeneration After Acetaminophen Overdose
Authors: Borude Prachi , Bhushan Bharat , Chavan Hemantkumar , Weemhoff James L. , Jaeschke Hartmut , Krishnamurthy Partha , Apte Udayan 
Published: November 2023

Liver regeneration in response to acetaminophen (APAP) overdose is a critical determinant of final patient outcome. Intricate cellular signaling during liver regeneration triggers liver cell proliferation, wound healing (if required) and restoration of liver mass and function. The p53 tumor suppressor protein is a critical regulator of cell cycle and apoptosis. However its role in liver regeneration after APAP overdose induced Acute Liver Failure (ALF) is not known. The pathogenesis of acute liver failure induced by APAP overdose can be divided into three phases including initiation of injury (formation of a reactive metabolite NAPQI and protein adducts) progression of injury (oxidative stress, mitochondrial and DNA damage resulting in necrosis) and regeneration/recovery phase (cell proliferation, angiogenesis and tissue repair). Here we show that p53 plays a critical role in inhibiting progression of injury and liver regeneration following APAP overdose mediated Acute Liver Injury (ALI). Eight‐week‐old male WT and p53KO mice (C57BL/6J background) were studied over time course of 0 to 96 hr following treatment with APAP300 (300mg/kg). Histology and serum ALT analysis showed similar liver injury in WT and p53KO mice at 1 and 12 hr however p53KO mice had significantly higher injury at 24 hr after APAP treatment. Interestingly, despite higher liver injury p53KO mice recovered equally to WT mice at 48 and 96 hr after APAP administration. Transcriptome analysis using liver RNA at 12, 24, 48hr from both groups revealed that p53KO mice had disrupted metabolic homeostasis, induced pro‐inflammatory and proliferative signaling. Further, molecular analysis of these pathways was done to confirm the findings. p53KO mice showed prolonged steatosis, lower mitochondrial DNA content, reduced expression of TFAM and mitochondrial complexes up to 24hr correlating with prolonged higher liver injury. p53 targets involved in fatty acid homeostasis, SREBP2 protein and GAMT mRNA expression correlated with prolonged steatosis in p53KO group. Liver regeneration determined by PCNA staining and cell cycle protein expression demonstrated that p53KO mice had rapid liver regeneration. Western blot analysis of EGFR, ERK and AKT showed sustained growth factor signaling in p53KO mice than WT mice after APAP treatment. These data illustrate that p53 has stage specific role during APAP‐induced ALF. p53 prevents progression of liver injury by maintaining mitochondrial and metabolic homeostasis after APAP overdose induced ALI. Further, p53 regulates initiation of liver regeneration through inflammatory and proliferative signaling after APAP overdose. These studies have revealed a novel role of p53 in acute liver injury pathogenesis.Support or Funding InformationNational Center for Research Resources (5P20RR021940‐07) Liver Scholar Award by AASLD/American Liver Foundation R01 DK098414