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Valenti Z, Hehn G, Lark D. Metabolic Stress is Not Sufficient to Increase Skeletal Muscle Tissue Extracellular Vesicle Secretion in an Ex Vivo System. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.04340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zackary Valenti
- Health & Exercise ScienceColorado State UniversityFort CollinsCO
| | - Gabriella Hehn
- Health & Exercise ScienceColorado State UniversityFort CollinsCO
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Walker J, Valenti Z, Hehn G, Lark D. Estimating Protein in Intact Extracellular Vesicles Based on Intrinsic Autofluorescence Spectroscopy. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.05482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jacob Walker
- Health & Exercise ScienceColorado State UniversityFort CollinsCO
| | - Zackary Valenti
- Health & Exercise ScienceColorado State UniversityFort CollinsCO
| | - Gabriella Hehn
- Health & Exercise ScienceColorado State UniversityFort CollinsCO
| | - Daniel Lark
- Health & Exercise ScienceColorado State UniversityFort CollinsCO
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Affiliation(s)
| | | | - Daniel Lark
- Colorado State University, Fort Collins, CO, USA
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Litt MJ, Okoye GD, Lark D, Cakir I, Moore C, Barber MC, Atkinson J, Fessel J, Moslehi J, Cone RD. Loss of the melanocortin-4 receptor in mice causes dilated cardiomyopathy. eLife 2017; 6:28118. [PMID: 28829041 PMCID: PMC5577919 DOI: 10.7554/elife.28118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/26/2017] [Indexed: 01/04/2023] Open
Abstract
Haploinsufficiency of the melanocortin-4 receptor, the most common monogenetic obesity syndrome in humans, is associated with a reduction in autonomic tone, bradycardia, and incidence of obesity-associated hypertension. Thus, it has been assumed that melanocortin obesity syndrome may be protective with respect to obesity-associated cardiovascular disease. We show here that absence of the melanocortin-4 receptor (MC4R) in mice causes dilated cardiomyopathy, characterized by reduced contractility and increased left ventricular diameter. This cardiomyopathy is independent of obesity as weight matched diet induced obese mice do not display systolic dysfunction. Mc4r cardiomyopathy is characterized by ultrastructural changes in mitochondrial morphology and cardiomyocyte disorganization. Remarkably, testing of myocardial tissue from Mc4r-/- mice exhibited increased ADP stimulated respiratory capacity. However, this increase in respiration correlates with increased reactive oxygen species production - a canonical mediator of tissue damage. Together this study identifies MC4R deletion as a novel and potentially clinically important cause of heart failure.
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Affiliation(s)
- Michael J Litt
- Departments of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States
| | - G Donald Okoye
- Division of Cardiology, Vanderbilt University, Nashville, United States.,Cardio-Oncology Program, Department of Medicine, Vanderbilt University, Nashville, United States
| | - Daniel Lark
- Departments of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States
| | - Isin Cakir
- Life Sciences Institute, University of Michigan, Ann Arbor, United States
| | - Christy Moore
- Allergy Pulmonary and Critical Care, Vanderbilt University Department of Medicine, Nashville, United States
| | - Mary C Barber
- Division of Cardiology, Vanderbilt University, Nashville, United States.,Cardio-Oncology Program, Department of Medicine, Vanderbilt University, Nashville, United States
| | - James Atkinson
- Department of Pathology, Vanderbilt University Medical Center, Nashville, United States
| | - Josh Fessel
- Allergy Pulmonary and Critical Care, Vanderbilt University Department of Medicine, Nashville, United States
| | - Javid Moslehi
- Division of Cardiology, Vanderbilt University, Nashville, United States.,Cardio-Oncology Program, Department of Medicine, Vanderbilt University, Nashville, United States
| | - Roger D Cone
- Departments of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States.,Life Sciences Institute, University of Michigan, Ann Arbor, United States.,Department of Molecular and Integrative Physiology, University of Michigan School of Medicine, Ann Arbor, United States
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Schmidt MA, O'Hanley P, Lark D, Schoolnik GK. Synthetic peptides corresponding to protective epitopes of Escherichia coli digalactoside-binding pilin prevent infection in a murine pyelonephritis model. Proc Natl Acad Sci U S A 1988; 85:1247-51. [PMID: 2448796 PMCID: PMC279744 DOI: 10.1073/pnas.85.4.1247] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Synthetic peptides corresponding to five segments of a globoside (Gal-Gal)-binding pilin sequence [residues 5-12 (R5-12), R65-75, R93-104, R103-116, and R131-143], cyanogen bromide fragment II (CNBr-II, R53-163), and purified, intact Gal-Gal pili were prepared as vaccines and tested for their efficacy in a BALB/c murine model of pyelonephritis. Intact Gal-Gal pili, CNBr-II, and synthetic peptides R5-12 and R65-75 engendered antibodies that bound the homologous pilin protein and prevented urine and renal colonization in most vaccine recipients. Protection correlated with serum anti-pilus IgG ELISA titers greater than or equal to 1:250. The efficacy afforded by synthetic peptides R5-12 and R65-75 in vaccinated mice indicates that linear "antigenic" determinants in separate cyanogen bromide fragments encode "protective" epitopes. Peptides R93-104, R103-116, and R131-143 lacked efficacy, indicating that not all regions of the sequence are serologically equivalent. The crossreactivity of the peptide antisera for different Gal-Gal pilins was also assessed and correlated with the sequence homology of the corresponding regions. Antiserum to peptide R65-75, which corresponds to a region of unconserved sequence in heterologous pilins, bound only the homologous pilin. Thus, it specifies a type-specific protective epitope. Antiserum to synthetic peptide R5-12, which corresponds to a region of conserved sequence, bound Gal-Gal pilins from seven of eight pyelonephritis strains, indicating that it specifies a crossreacting protective epitope.
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Affiliation(s)
- M A Schmidt
- Department of Medicine, Stanford University School of Medicine, CA 94305
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Schoolnik GK, O'Hanley P, Lark D, Normark S, Vosti K, Falkow S. Uropathogenic Escherichia coli: molecular mechanisms of adherence. Adv Exp Med Biol 1987; 224:53-62. [PMID: 3329813 DOI: 10.1007/978-1-4684-8932-3_5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- G K Schoolnik
- Medical Service, Palo Alto Veterans Administration Medical Center, California
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O'Hanley P, Low D, Romero I, Lark D, Vosti K, Falkow S, Schoolnik G. Gal-Gal binding and hemolysin phenotypes and genotypes associated with uropathogenic Escherichia coli. N Engl J Med 1985; 313:414-20. [PMID: 2862582 DOI: 10.1056/nejm198508153130704] [Citation(s) in RCA: 138] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
To determine whether uropathogenic strains of Escherichia coli exhibit a distinctive constellation of phenotypes, we examined 44 urinary isolates from women with radiologically normal urinary tracts and pyelonephritis, cystitis, or asymptomatic bacteriuria and 73 fecal isolates from healthy control subjects. The strains were characterized by their O serogroup, by their binding specificity (as determined by adhesins), and by their production of hemolysin and colicin V. In addition, the strains were assessed for homologous gene sequences by means of DNA-hybridization probes prepared from cistrons that encode hemolysin and the Gal-Gal binding adhesin--two determinants of virulence, which cause tissue injury and promote bacterial colonization of uroepithelia, respectively. In contrast to most isolates from normal feces and from the urine of patients with asymptomatic bacteriuria, pyelonephritis strains belong to a small number of O serogroups; all express the Gal--Gal binding adhesin and 75 per cent are hemolytic. A gene probe for the Gal--Gal binding adhesin, derived from the chromosome of one strain from a patient with pyelonephritis, hybridized with the DNA of all other pyelonephritis strains. The probe for the hemolysin gene hybridized with DNA from all other hemolytic strains. These data indicate that most cases of pyelonephritis are due to a small number of pathogenic clones that express critical determinants of virulence, and that the nucleotide sequences for hemolysin and the Gal--Gal binding adhesin in heterologous strains share homology. We are tempted to speculate that the gene products of these shared regions of the genome might form the basis for a vaccine against pyelonephritis.
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O'Hanley P, Lark D, Falkow S, Schoolnik G. Molecular basis of Escherichia coli colonization of the upper urinary tract in BALB/c mice. Gal-Gal pili immunization prevents Escherichia coli pyelonephritis in the BALB/c mouse model of human pyelonephritis. J Clin Invest 1985; 75:347-60. [PMID: 2857730 PMCID: PMC423490 DOI: 10.1172/jci111707] [Citation(s) in RCA: 180] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Most human pyelonephritis Escherichia coli isolates express both mannose (MS)- and globoside (Gal-Gal)-binding pili. An ascending E. coli urinary tract infection model was established in the 16-wk-old female BALB/c mouse to compare the pathogenic significance of MS and Gal-Gal pili and their efficacy as vaccines for the prevention of pyelonephritis. The distribution and density of pilus receptor compounds in urogenital tissues and as soluble compounds in urine were determined with antibodies to the synthetic receptor analogues, alpha D-Gal(1----4) beta D-Gal and alpha D-Man(1----2) alpha D-Man. Both carbohydrates were detected in vagina, bladder, ureter, and renal pelvis epithelium and in collecting duct and tubular cells. A pilus receptor compound also was detected in urine. It competitively inhibited the binding capacity of MS pili and was found to be physically, chemically, and immunologically related to Tamm-Horsfall uromucoid. Infectivity and invasiveness were quantitatively and histologically characterized for four E. coli strains: J96, a human pyelonephritis strain that expresses both MS and Gal-Gal pili; two recombinant strains prepared from J96 chromosomal DNA encoding MS pili or Gal-Gal pili; and the nonpiliated K12 recipient. Intravesicular administration of J96 (10(6) colony-forming units [CFU]) resulted in renal colonization and invasion in each of nine mice. The Gal-Gal clone (10(6) CFU) colonized the kidneys in each of 10 mice but did not invade. In contrast, the MS clone (10(6) CFU) did not colonize renal epithelium or invade. This effect was superceded when larger doses (greater than or equal to 10(10) CFU) of the MS clone were administered in volumes that cause acute vesicoureteric reflux. The efficacy was determined of vaccines composed of pure MS or Gal-Gal pili or the lipopolysaccharide containing O somatic antigen of the challenge strain, J96. The Gal-Gal pilus vaccine blocked renal colonization in 19 of 22 mice and renal invasion in 10 of 11 mice. Gal-Gal pili may be useful immunogens for the prevention of pyelonephritis in anatomically normal urinary tracts.
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Labigne-Roussel AF, Lark D, Schoolnik G, Falkow S. Cloning and expression of an afimbrial adhesin (AFA-I) responsible for P blood group-independent, mannose-resistant hemagglutination from a pyelonephritic Escherichia coli strain. Infect Immun 1984; 46:251-9. [PMID: 6148308 PMCID: PMC261465 DOI: 10.1128/iai.46.1.251-259.1984] [Citation(s) in RCA: 181] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The uropathogenic Escherichia coli KS52 strain expresses a mannose-resistant hemagglutinin involving an erythrocyte recognition site distinct from the alpha-digalactoside glycosphingolipid receptor identified for the uropathogenic E. coli strains specifying a P adhesin. The KS52 strain showed three major properties. (i) It agglutinated human erythrocytes of all tested blood groups. (ii) Hemagglutinin activity was found both in the supernatant fluid L-broth cultures and in cells grown on L-agar plates. (iii) No fimbriae in organisms grown on L-agar plates were detected by electron microscopy. Whole-cell DNA from the KS52 strain was size fractionated and cloned into the pHC79 cosmid vector. Three recombinant cosmids expressing a mannose-resistant hemagglutination (MRHA) phenotype were characterized and used to subclone the smallest DNA fragment able to confer the same MRHA properties as the parent strain. A 6.7-kilobase chromosomal DNA fragment cloned in pBR322 (pIL14) was shown to be necessary for host-cell MRHA expression and uroepithelial cell adherence. The insert encoded the production of a 16,000-dalton hemagglutinin. This polypeptide could be detected in culture supernatant fluids, in E. coli minicells harboring the pIL14 plasmid, and, by immunoblotting, in the KS52 strain and E. coli whole cells harboring the pIL14 plasmid. No homology was detected by Southern hybridization between the cloned insert and the DNA of the operon responsible for MRHA in the P-specifying, fimbriate strains (pap operon).
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Norgren M, Normark S, Lark D, O'Hanley P, Schoolnik G, Falkow S, Svanborg-Edén C, Båga M, Uhlin BE. Mutations in E coli cistrons affecting adhesion to human cells do not abolish Pap pili fiber formation. EMBO J 1984; 3:1159-65. [PMID: 6145589 PMCID: PMC557489 DOI: 10.1002/j.1460-2075.1984.tb01945.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
A chromosomal DNA fragment which mediates Pap (pili associated with pyelonephritis) pili formation, mannose-resistant hemagglutination ( MRHA ) and binding to uroepithelial cells has been isolated from the uropathogenic Escherichia coli clinical isolate J96 , and genetically studied. Analysis of polypeptides expressed by the Pap DNA led to detection of a number of polypeptides ranging in mol. wt. from 13 000 to 81 000 daltons. The gene order and transcriptional orientation for four of the corresponding cistrons was: 13 000 ( papB ) 19 500 ( papA , structural gene for the Pap pilus subunit), 81 000 ( papC ) and 28 500 ( papD ). Analyses of a lacZ- papA gene fusion located a promoter upstream from papA within the cloned DNA. Transposon Tn5 insertions in any of these four cistrons decreased or eliminated Pap pili formation. A number of transposon Tn5 mutations were identified in a region distal to papD that expressed normal levels of the papA protein on the cell surface in the form of recognizable pili structures but did not agglutinate human erythrocytes or adhere to uroepithelial cells. This region expressed polypeptides of 15 000, 24 000, 26 000 and 35 000 daltons. This finding shows that Pap pili formation and binding properties can be genetically dissociated.
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Båga M, Normark S, Hardy J, O'Hanley P, Lark D, Olsson O, Schoolnik G, Falkow S. Nucleotide sequence of the papA gene encoding the Pap pilus subunit of human uropathogenic Escherichia coli. J Bacteriol 1984; 157:330-3. [PMID: 6140260 PMCID: PMC215181 DOI: 10.1128/jb.157.1.330-333.1984] [Citation(s) in RCA: 139] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The papA gene of the uropathogenic strain Escherichia coli J96, coding for the Pap pili subunit, was subjected to DNA sequencing, and found to code for an 185-amino acid-long polypeptide with a 22-amino acid-long signal peptide. Here we present the primary sequence, the hydrophilicity profile, and the predicted polypeptide secondary structure of the Pap pili subunit.
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Low D, David V, Lark D, Schoolnik G, Falkow S. Gene clusters governing the production of hemolysin and mannose-resistant hemagglutination are closely linked in Escherichia coli serotype O4 and O6 isolates from urinary tract infections. Infect Immun 1984; 43:353-8. [PMID: 6317570 PMCID: PMC263434 DOI: 10.1128/iai.43.1.353-358.1984] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The genes encoding alpha-hemolysin and mannose-resistant hemagglutination were shown to be closely linked in cloned DNA from two Escherichia coli urinary tract isolates of serotypes O4 (J96) and O6 (C1212). DNA hybridization experiments demonstrated that the hly and mrh gene clusters of other E. coli O6 serotypes were also linked. Colony hybridizations showed that most normal fecal E. coli do not contain hly and mrh DNA but much of the intervening DNA between these two gene clusters is common among all E. coli. We have further demonstrated that there is a small (about 1 kilobase) region of homology located on both sides of the hly sequence and present elsewhere in the C1212 strain. We suggest that linkage of hly and mrh occurred through a transposition event, and we discuss the potential significance of this linkage in the acquisition of virulence determinants by these bacteria.
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O'Hanley P, Lark D, Normark S, Falkow S, Schoolnik GK. Mannose-sensitive and Gal-Gal binding Escherichia coli pili from recombinant strains. Chemical, functional, and serological properties. J Exp Med 1983; 158:1713-19. [PMID: 6195290 PMCID: PMC2187145 DOI: 10.1084/jem.158.5.1713] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Chromosomal genes encoding the MS and Gal-Gal binding properties have been cloned into separate recombinants and their respective pili characterized. Hapten inhibition of hemagglutination with synthetic carbohydrate receptor analogues and carbohydrate-adsorbed latex agglutination studies indicate that Gal-Gal and MS pili collectively exhibit the binding properties of the parent strain. MS pili migrated in SDS-PAGE with an Mr of 19 kdaltons and 17 kdaltons; the Mr of Gal-Gal pili was 17.5 kdaltons. The pili are chemically similar by amino acid composition and when the N-terminal cysteines are aligned, 8 of the 13 residues between positions 9 and 22 are homologous. Further, carboxy-terminal sequence homology was inferred from the carboxypeptidase digestion of a MS pili and the sequence of a carboxy-terminal tryptic peptide from Gal-Gal pili.
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Normark S, Lark D, Hull R, Norgren M, Båga M, O'Hanley P, Schoolnik G, Falkow S. Genetics of digalactoside-binding adhesin from a uropathogenic Escherichia coli strain. Infect Immun 1983; 41:942-9. [PMID: 6136465 PMCID: PMC264592 DOI: 10.1128/iai.41.3.942-949.1983] [Citation(s) in RCA: 151] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The uropathogenic strain Escherichia coli J96 mediates mannose-resistant hemagglutination owing to production of a digalactoside-binding adhesin. A cosmid clone from this strain has been isolated that, when harbored in E. coli K-12, expressed Pap pili and this adhesin (R. Hull et al., Infect. Immun. 33:933-938, 1981). By transposon mutagenesis and by the construction of a number of hybrid plasmid derivatives, we have demonstrated that about 8.5 kilobases of DNA is required to generate a mannose-resistant hemagglutination-positive phenotype in E. coli K-12 strain P678-54. The structural gene for the Pap pili monomer, papA, has been identified and mapped close to the promotor-proximal end of the Pap operon. Although strain P678-54 that harbored a Tn5 insertion within papA showed a mannose-resistant hemagglutination-positive phenotype, it was negative in a competitive enzyme-linked immunosorbent assay with anti-Pap pilus serum. This could mean that a Pap adhesin is encoded by a region on the Pap operon that is distinct from papA.
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Burr DB, Cook LT, Cilento EV, Martin NL, Lark D, Asher M. A method for radiographically measuring true femoral rotation. Clin Orthop Relat Res 1982:139-44. [PMID: 7094455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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