1
|
Plakoglobin and High-Mobility Group Box 1 Mediate Intestinal Epithelial Cell Apoptosis Induced by Clostridioides difficile TcdB. mBio 2022; 13:e0184922. [PMID: 36043787 DOI: 10.1128/mbio.01849-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clostridioides difficile infection (CDI) is the leading cause of antibiotic-associated intestinal disease, resulting in severe diarrhea and fatal pseudomembranous colitis. TcdB, one of the essential virulence factors secreted by this bacterium, induces host cell apoptosis through a poorly understood mechanism. Here, we performed an RNA interference (RNAi) screen customized to Caco-2 cells, a cell line model of the intestinal epithelium, to discover host factors involved in TcdB-induced apoptosis. We identified plakoglobin, also known as junction plakoglobin (JUP) or γ-catenin, a member of the catenin family, as a novel host factor and a previously known cell death-related chromatin factor, high-mobility group box 1 (HMGB1). Disruption of those host factors by RNAi and CRISPR resulted in resistance of cells to TcdB-mediated and mitochondrion-dependent apoptosis. JUP was redistributed from adherens junctions to the mitochondria and colocalized with the antiapoptotic factor Bcl-XL. JUP proteins could permeabilize the mitochondrial membrane, resulting in the release of cytochrome c. Our results reveal a novel role of JUP in targeting the mitochondria to promote the mitochondrial apoptotic pathway. Treatment with glycyrrhizin, an HMGB1 inhibitor, resulted in significantly increased resistance to TcdB-induced epithelial damage in cultured cells and a mouse ligated colon loop model. These findings demonstrate the critical roles of JUP and HMGB1 in TcdB-induced epithelial cell apoptosis. IMPORTANCE Clostridioides difficile infection (CDI) is the leading cause of hospital-acquired diarrhea. Toxins, especially TcdB, cause epithelial cell apoptosis, but the underlying cell death mechanism is less clear. Through an apoptosis-focused RNAi screen using a bacterium-made small interfering (siRNA) library customized to a human colonic epithelial cell model, we found a novel host factor, plakoglobin (γ-catenin), as a key factor required for cell apoptosis induced by TcdB. Plakoglobin targets and permeabilizes mitochondria after stimulation by TcdB, demonstrating a hitherto underappreciated role of this catenin family member in the apoptosis of intestinal epithelial cells. We also found a previously known cell death-related chromatin factor, HMGB1, and explored the inhibition of HMGB1 for CDI therapy in vivo.
Collapse
|
2
|
Chen Z, Li R, Pei LG, Wei ZH, Xie J, Wu H, Xu B. High-mobility group box-1 promotes vascular calcification in diabetic mice via endoplasmic reticulum stress. J Cell Mol Med 2021; 25:3724-3734. [PMID: 33724642 PMCID: PMC8051722 DOI: 10.1111/jcmm.16075] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 10/05/2020] [Accepted: 10/25/2020] [Indexed: 12/20/2022] Open
Abstract
Several studies reported the role of endoplasmic reticulum stress (ERS) in vascular calcification. High-mobility group box-1 (HMGB-1) plays a substantial role in diabetes and its complications. However, relatively little information is available regarding the association between HMGB-1 and calcification, and the underlying mechanism has still remained elusive. Therefore, in the present study, we attempted to indicate whether HMGB-1 could promote vascular calcification via ERS in diabetes. After induction of diabetes by Streptozotocin (STZ), mice were treated with glycyrrhizin (Gly) or 4-phenylbutyrate (4-PBA). Mineral deposition was confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and calcium assay. In cell experiments, calcification of vascular smooth muscle cells (VSMCs) was performed with Alizarin Red staining, alkaline phosphatase (ALP) activity and RT-PCR. Expression and location of HMGB-1 in aortic tissue were detected by Western blotting, immunocytochemistry (ICC) and immunohistochemistry (IHC). Diabetic mice demonstrated increased HMGB-1 expression, ERS and vascular calcification. However, inhibition of HMGB-1 with Gly or inhibition of ERS with 4-PBA ameliorated the enhanced vascular calcification and ERS in diabetic mice. In vitro experiments unveiled that inhibition of HMGB-1 attenuated advanced glycation end products (AGEs)-induced ERS in VSMCs. In addition, AGEs promoted translocation and secretion of HMGB-1 in VSMCs, which was reversed by 4-PBA. Moreover, VSMCs exhibited increased mineralization and osteogenic gene expressions in response to HMGB-1 and AGEs. However, inhibition of ERS with 4-PBA partially, although noticeably, attenuated VSMC calcification induced by HMGB-1. Thus, diabetes induced translocation and secretion of HMGB-1 via ERS, which resulted in calcification in diabetic mice and in AGEs-treated VSMCs.
Collapse
Affiliation(s)
- Zheng Chen
- Department of Cardiology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Ran Li
- Department of Cardiology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Li-Gang Pei
- Department of Cardiology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Zhong-Hai Wei
- Department of Cardiology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Jun Xie
- Department of Cardiology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Han Wu
- Department of Cardiology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Biao Xu
- Department of Cardiology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| |
Collapse
|
3
|
Lin M, Long J, Li W, Yang C, Loughran P, O'Doherty R, Billiar TR, Deng M, Scott MJ. Hepatocyte high-mobility group box 1 protects against steatosis and cellular stress during high fat diet feeding. Mol Med 2020; 26:115. [PMID: 33238880 PMCID: PMC7687718 DOI: 10.1186/s10020-020-00227-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/13/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Circulating high-mobility group box 1 (HMGB1) plays important roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Intracellular HMGB1 is critical for the biology of hepatocytes. However, the intracellular role of HMGB1 in hepatocellular steatosis is unknown. Therefore, we aimed to investigate the role of hepatocyte-specific HMGB1 (HC-HMGB1) in development of hepatic steatosis. METHODS Wild type (WT) C57BL/6 and HC-HMGB1-/- mice were fed high-fat diet (HFD) or low-fat diet (LFD) for up to 16 weeks. RESULTS As expected, HMGB1 translocated from nuclear into cytoplasm and released into circulation after HFD treatment. HC-HMGB1 deficiency significantly reduced circulating HMGB1, suggesting that hepatocyte is a major source of circulating HMGB1 during NAFLD. Unexpectedly, HC-HMGB1 deficiency promoted rapid weight gain with enhanced hepatic fat deposition compared with WT at as early as 4 weeks after HFD treatment. Furthermore, there was no difference between WT and HC-HMGB1-/- mice in glucose tolerance, energy expenditure, liver damage or systemic inflammation. Interestingly, hepatic gene expression related to free fatty acid (FFA) β-oxidation was significantly down-regulated in HC-HMGB1-/- mice compared with WT, and endoplasmic reticulum (ER) stress markers were significantly higher in livers of HC-HMGB1-/- mice. In vitro experiments using primary mouse hepatocytes showed absence of HMGB1 increased FFA-induced intracellular lipid accumulation, accompanied by increased ER-stress, significant downregulation of FFA β-oxidation, and reduced oxidative phosphorylation. CONCLUSIONS Our findings suggest that hepatocyte HMGB1 protects against dysregulated lipid metabolism via maintenance of β-oxidation and prevention of ER stress. This represents a novel mechanism for HMGB1-regulation of hepatocellular steatosis, and suggests that stabilizing HMGB1 in hepatocytes may be effective strategies for prevention and treatment of NAFLD.
Collapse
Affiliation(s)
- Minjie Lin
- Clinical Skills Training Center, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Jungke Long
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
- Department of Cardiology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China
| | - Wenbo Li
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
- Department of Plastic Surgery, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China
| | - Chenxuan Yang
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
- Tsinghua University School of Medicine, Beijing, 100084, China
| | - Patricia Loughran
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Robert O'Doherty
- The Center for Metabolism and Mitochondrial Medicine of University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Meihong Deng
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
- University of Pittsburgh, NW607 MUH, 3459 Fifth Ave, Pittsburgh, PA, 15213, USA.
| | - Melanie J Scott
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
- University of Pittsburgh, NW653 MUH, 3459 Fifth Ave, Pittsburgh, PA, 15213, USA.
| |
Collapse
|
4
|
Czepiel J, Biesiada G, Pitera E, Wołkow PP, Michalak M, Garlicki A. Decreased Expression of the High Mobility Group Box 1 ( HMGB1) Gene in Peripheral Blood in Patients with Mild or Moderate Clostridioides difficile Infection. Microorganisms 2020; 8:microorganisms8081217. [PMID: 32796569 PMCID: PMC7464922 DOI: 10.3390/microorganisms8081217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/05/2020] [Accepted: 08/07/2020] [Indexed: 12/17/2022] Open
Abstract
Cytokines are mediators of inflammation induced in the course of Clostridioides difficile infection (CDI). High Mobility Group Box 1 (HMGB1) is a cytokine playing an important role in the pathogenesis of numerous inflammatory and autoimmune diseases. The aim of the study was to assess the HMGB1 gene expression in the course of CDI. We have performed a prospective case-control study- including 55 adult patients, among them 27 with CDI, who were hospitalized from October 2018 to February 2020 and 28 healthy volunteers. We assessed: a complete blood count with differential leukocyte count, blood creatinine, albumin, and C-reactive protein (CRP) levels. Then, the expression of the HMGB1 gene was evaluated using quantitative Real-Time PCR. Patients with CDI were found to have a significant increase in white blood cells (WBC), neutrophil count, and CRP levels, they also exhibited decreased levels of albumin compared with controls. The HMGB1 gene expression was significantly lower among patients with CDI compared with the control group and significantly, inversely correlated with CRP level in blood. In conclusion, we have observed a decreased expression of the HMGB1 gene in peripheral blood of patients with mild or moderate CDI, which hypothetically could reflect their diminished capability to fight the pathogen.
Collapse
Affiliation(s)
- Jacek Czepiel
- Department of Infectious and Tropical Diseases, Jagiellonian University Medical College, 30-688 Krakow, Poland; (G.B.); (A.G.)
- Correspondence: ; Tel./Fax: +48-124-002022/17
| | - Grażyna Biesiada
- Department of Infectious and Tropical Diseases, Jagiellonian University Medical College, 30-688 Krakow, Poland; (G.B.); (A.G.)
| | - Ewelina Pitera
- Center for Medical Genomics OMICRON, Jagiellonian University Medical College, 31-034 Krakow, Poland; (E.P.); (P.P.W.)
| | - Paweł P. Wołkow
- Center for Medical Genomics OMICRON, Jagiellonian University Medical College, 31-034 Krakow, Poland; (E.P.); (P.P.W.)
- Department of Pharmacology, Jagiellonian University Medical College, 31-531 Krakow, Poland
| | | | - Aleksander Garlicki
- Department of Infectious and Tropical Diseases, Jagiellonian University Medical College, 30-688 Krakow, Poland; (G.B.); (A.G.)
| |
Collapse
|
5
|
Kuss-Duerkop SK, Keestra-Gounder AM. NOD1 and NOD2 Activation by Diverse Stimuli: a Possible Role for Sensing Pathogen-Induced Endoplasmic Reticulum Stress. Infect Immun 2020; 88:e00898-19. [PMID: 32229616 PMCID: PMC7309630 DOI: 10.1128/iai.00898-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Prompt recognition of microbes by cells is critical to eliminate invading pathogens. Some cell-associated pattern recognition receptors (PRRs) recognize and respond to microbial ligands. However, others can respond to cellular perturbations, such as damage-associated molecular patterns (DAMPs). Nucleotide oligomerization domains 1 and 2 (NOD1/2) are PRRs that recognize and respond to multiple stimuli of microbial and cellular origin, such as bacterial peptidoglycan, viral infections, parasitic infections, activated Rho GTPases, and endoplasmic reticulum (ER) stress. How NOD1/2 are stimulated by such diverse stimuli is not fully understood but may partly rely on cellular changes during infection that result in ER stress. NOD1/2 are ER stress sensors that facilitate proinflammatory responses for pathogen clearance; thus, NOD1/2 may help mount broad antimicrobial responses through detection of ER stress, which is often induced during a variety of infections. Some pathogens may subvert this response to promote infection through manipulation of NOD1/2 responses to ER stress that lead to apoptosis. Here, we review NOD1/2 stimuli and cellular responses. Furthermore, we discuss pathogen-induced ER stress and how it might potentiate NOD1/2 signaling.
Collapse
Affiliation(s)
- Sharon K Kuss-Duerkop
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - A Marijke Keestra-Gounder
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| |
Collapse
|