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Findinier J, Joubert LM, Schmid MF, Malkovskiy A, Chiu W, Burlacot A, Grossman AR. Dramatic Changes in Mitochondrial Subcellular Location and Morphology Accompany Activation of the CO 2 Concentrating Mechanism. bioRxiv 2024:2024.03.25.586705. [PMID: 38585955 PMCID: PMC10996633 DOI: 10.1101/2024.03.25.586705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Dynamic changes in intracellular ultrastructure can be critical for the ability of organisms to acclimate to environmental conditions. Microalgae, which are responsible for ~50% of global photosynthesis, compartmentalize their Rubisco into a specialized structure known as the pyrenoid when the cells experience limiting CO2 conditions; this compartmentalization appears to be a component of the CO2 Concentrating Mechanism (CCM), which facilitates photosynthetic CO2 fixation as environmental levels of inorganic carbon (Ci) decline. Changes in the spatial distribution of mitochondria in green algae have also been observed under CO2 limiting conditions, although a role for this reorganization in CCM function remains unclear. We used the green microalgae Chlamydomonas reinhardtii to monitor changes in the position and ultrastructure of mitochondrial membranes as cells transition between high CO2 (HC) and Low/Very Low CO2 (LC/VLC). Upon transferring cells to VLC, the mitochondria move from a central to a peripheral location, become wedged between the plasma membrane and chloroplast envelope, and mitochondrial membranes orient in parallel tubular arrays that extend from the cell's apex to its base. We show that these ultrastructural changes require protein and RNA synthesis, occur within 90 min of shifting cells to VLC conditions, correlate with CCM induction and are regulated by the CCM master regulator CIA5. The apico-basal orientation of the mitochondrial membrane, but not the movement of the mitochondrion to the cell periphery, is dependent on microtubules and the MIRO1 protein, which is involved in membrane-microtubule interactions. Furthermore, blocking mitochondrial electron transport in VLC acclimated cells reduces the cell's affinity for inorganic carbon. Overall, our results suggest that CIA5-dependent mitochondrial repositioning/reorientation functions in integrating cellular architecture and energetics with CCM activities and invite further exploration of how intracellular architecture can impact fitness under dynamic environmental conditions.
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Affiliation(s)
- Justin Findinier
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
| | - Lydia-Marie Joubert
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
| | - Michael F. Schmid
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
| | - Andrey Malkovskiy
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
| | - Wah Chiu
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
- Stanford University, Department of Bioengineering, Stanford, CA 94305, USA
| | - Adrien Burlacot
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
- Stanford University, Biology Department, Stanford, CA 94305, USA
| | - Arthur R. Grossman
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
- Stanford University, Biology Department, Stanford, CA 94305, USA
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2
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Gerrick ER, DeSchepper LB, Mechler CM, Joubert LM, Dunker F, Colston TJ, Howitt MR. Commensal protists in reptiles display flexible host range and adaptation to ectothermic hosts. mBio 2023; 14:e0227323. [PMID: 37962346 PMCID: PMC10746265 DOI: 10.1128/mbio.02273-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 10/04/2023] [Indexed: 11/15/2023] Open
Abstract
IMPORTANCE Environmental factors like climate change and captive breeding can impact the gut microbiota and host health. Therefore, conservation efforts for threatened species may benefit from understanding how these factors influence animal microbiomes. Parabasalid protists are members of the mammalian microbiota that can modulate the immune system and impact susceptibility to infections. However, little is known about parabasalids in reptiles. Here, we profile reptile-associated parabasalids in wild and captive reptiles and find that captivity has minimal impact on parabasalid prevalence or diversity. However, because reptiles are cold-blooded (ectothermic), their microbiotas experience wider temperature fluctuation than microbes in warm-blooded animals. To investigate whether extreme weather patterns affect parabasalid-host interactions, we analyzed the gene expression in reptile-associated parabasalids and found that temperature differences significantly alter genes associated with host health. These results expand our understanding of parabasalids in this vulnerable vertebrate group and highlight important factors to be taken into consideration for conservation efforts.
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Affiliation(s)
- Elias R. Gerrick
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Leila B. DeSchepper
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Claire M. Mechler
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility (CSIF), Stanford University, Stanford, California, USA
| | - Freeland Dunker
- Steinhart Aquarium, California Academy of Sciences, San Francisco, California, USA
| | | | - Michael R. Howitt
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
- Department of Microbiology, Stanford University School of Medicine, Stanford, California, USA
- Program in Immunology, Stanford University School of Medicine, Stanford, California, USA
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3
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Gerrick ER, DeSchepper LB, Mechler CM, Joubert LM, Dunker F, Colston TJ, Howitt MR. Commensal protists in reptiles display flexible host range and adaptation to ectothermic hosts. bioRxiv 2023:2023.05.25.542353. [PMID: 37292851 PMCID: PMC10245904 DOI: 10.1101/2023.05.25.542353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Parabasalid protists recently emerged as keystone members of the mammalian microbiota with important effects on their host's health. However, the prevalence and diversity of parabasalids in wild reptiles and the consequences of captivity and other environmental factors on these symbiotic protists are unknown. Reptiles are ectothermic, and their microbiomes are subject to temperature fluctuations, such as those driven by climate change. Thus, conservation efforts for threatened reptile species may benefit from understanding how shifts in temperature and captive breeding influence the microbiota, including parabasalids, to impact host fitness and disease susceptibility. Here, we surveyed intestinal parabasalids in a cohort of wild reptiles across three continents and compared these to captive animals. Reptiles harbor surprisingly few species of parabasalids compared to mammals, but these protists exhibited a flexible host-range, suggesting specific adaptations to reptilian social structures and microbiota transmission. Furthermore, reptile-associated parabasalids are adapted to wide temperature ranges, although colder temperatures significantly altered the protist transcriptomes, with increased expression of genes associated with detrimental interactions with the host. Our findings establish that parabasalids are widely distributed in the microbiota of wild and captive reptiles and highlight how these protists respond to temperature swings encountered in their ectothermic hosts.
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Affiliation(s)
- Elias R Gerrick
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Leila B DeSchepper
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Claire M Mechler
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility (CSIF), Stanford University, Stanford, CA 94305, USA
| | - Freeland Dunker
- Steinhart Aquarium, California Academy of Science, San Francisco, CA 94118, USA
| | - Timothy J Colston
- Biology Department, University of Puerto Rico at Mayagüez, Call Box 9000, 00681-9000 Mayagüez, Puerto Rico
| | - Michael R Howitt
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Lead Contact
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4
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Wu GH, Smith-Geater C, Galaz-Montoya JG, Gu Y, Gupte SR, Aviner R, Mitchell PG, Hsu J, Miramontes R, Wang KQ, Geller NR, Hou C, Danita C, Joubert LM, Schmid MF, Yeung S, Frydman J, Mobley W, Wu C, Thompson LM, Chiu W. CryoET reveals organelle phenotypes in huntington disease patient iPSC-derived and mouse primary neurons. Nat Commun 2023; 14:692. [PMID: 36754966 PMCID: PMC9908936 DOI: 10.1038/s41467-023-36096-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 01/13/2023] [Indexed: 02/10/2023] Open
Abstract
Huntington's disease (HD) is caused by an expanded CAG repeat in the huntingtin gene, yielding a Huntingtin protein with an expanded polyglutamine tract. While experiments with patient-derived induced pluripotent stem cells (iPSCs) can help understand disease, defining pathological biomarkers remains challenging. Here, we used cryogenic electron tomography to visualize neurites in HD patient iPSC-derived neurons with varying CAG repeats, and primary cortical neurons from BACHD, deltaN17-BACHD, and wild-type mice. In HD models, we discovered sheet aggregates in double membrane-bound organelles, and mitochondria with distorted cristae and enlarged granules, likely mitochondrial RNA granules. We used artificial intelligence to quantify mitochondrial granules, and proteomics experiments reveal differential protein content in isolated HD mitochondria. Knockdown of Protein Inhibitor of Activated STAT1 ameliorated aberrant phenotypes in iPSC- and BACHD neurons. We show that integrated ultrastructural and proteomic approaches may uncover early HD phenotypes to accelerate diagnostics and the development of targeted therapeutics for HD.
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Affiliation(s)
- Gong-Her Wu
- Department of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA, 94305, USA
| | - Charlene Smith-Geater
- Department of Psychiatry & Human Behavior University of California Irvine, Irvine, CA, 92697, USA
| | - Jesús G Galaz-Montoya
- Department of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA, 94305, USA
| | - Yingli Gu
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92037-0662, USA
| | - Sanket R Gupte
- Department of Computer Science, Stanford University, Stanford, CA, 94305, USA
| | - Ranen Aviner
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Patrick G Mitchell
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, 94025, USA
| | - Joy Hsu
- Department of Computer Science, Stanford University, Stanford, CA, 94305, USA
| | - Ricardo Miramontes
- Department of Memory Impairment and Neurological Disorders, University of California Irvine, Irvine, CA, 92697, USA
| | - Keona Q Wang
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, CA, 96267, USA
| | - Nicolette R Geller
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, CA, 96267, USA
| | - Cathy Hou
- Department of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA, 94305, USA
| | - Cristina Danita
- Department of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA, 94305, USA
| | - Lydia-Marie Joubert
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, 94025, USA
| | - Michael F Schmid
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, 94025, USA
| | - Serena Yeung
- Department of Computer Science, Stanford University, Stanford, CA, 94305, USA.,Department of Biomedical Data Science, Stanford University, Stanford, CA, 94305, USA
| | - Judith Frydman
- Department of Biology, Stanford University, Stanford, CA, 94305, USA.,Department of Genetics, Stanford University, Stanford, CA, 94305, USA
| | - William Mobley
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92037-0662, USA
| | - Chengbiao Wu
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92037-0662, USA
| | - Leslie M Thompson
- Department of Psychiatry & Human Behavior University of California Irvine, Irvine, CA, 92697, USA. .,Department of Memory Impairment and Neurological Disorders, University of California Irvine, Irvine, CA, 92697, USA. .,Department of Neurobiology and Behavior, University of California Irvine, Irvine, CA, 96267, USA. .,Sue & Bill Gross Stem Cell Research Center, University of California Irvine, Irvine, CA, 96267, USA. .,Department of Biological Chemistry, University of California Irvine, Irvine, CA, 92617, USA.
| | - Wah Chiu
- Department of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA, 94305, USA. .,Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, 94025, USA. .,Department of Microbiology and Immunology, Stanford University, Stanford, CA, 94305, USA.
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5
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Malkovskiy AV, Tom A, Joubert LM, Bao Z. Visualization of the distribution of covalently cross-linked hydrogels in CLARITY brain-polymer hybrids for different monomer concentrations. Sci Rep 2022; 12:13549. [PMID: 35941350 PMCID: PMC9360022 DOI: 10.1038/s41598-022-17687-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/29/2022] [Indexed: 11/09/2022] Open
Abstract
CLARITY is a tissue preservation and optical clearing technique whereby a hydrogel is formed directly within the architectural confines of ex vivo brain tissue. In this work, the extent of polymer gel formation and crosslinking within tissue was assessed using Raman spectroscopy and rheology on CLARITY samples prepared with a range of acrylamide monomer (AAm) concentrations (1%, 4%, 8%, 12% w/v). Raman spectroscopy of individual neurons within hybrids revealed the chemical presence and distribution of polyacrylamide within the mouse hippocampus. Consistent with rheological measurements, lower %AAm concentration decreased shear elastic modulus G', providing a practical correlation with sample permeability and protein retention. Permeability of F(ab)'2 secondary fluorescent antibody changes from 9.3 to 1.4 µm2 s-1 going from 1 to 12%. Notably, protein retention increased linearly relative to standard PFA-fixed tissue from 96.6% when AAm concentration exceeded 1%, with 12% AAm samples retaining up to ~ 99.3% native protein. This suggests that though 1% AAm offers high permeability, additional %AAm may be required to enhance protein. Our quantitative results on polymer distribution, stability, protein retention, and macromolecule permeability can be used to guide the design of future CLARITY-based tissue-clearing solutions, and establish protocols for characterization of novel tissue-polymer hybrid biomaterials using chemical spectroscopy and rheology.
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Affiliation(s)
| | - Ariane Tom
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility (CSIF), Stanford University, Stanford, CA, 94305, USA
| | - Zhenan Bao
- Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA.
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6
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Yu Z, Chen J, Takagi E, Wang F, Saha B, Liu X, Joubert LM, Gleason CE, Jin M, Li C, Nowotny C, Agard D, Cheng Y, Pearce D. Interactions between mTORC2 core subunits Rictor and mSin1 dictate selective and context-dependent phosphorylation of substrate kinases SGK1 and Akt. J Biol Chem 2022; 298:102288. [PMID: 35926713 PMCID: PMC9440446 DOI: 10.1016/j.jbc.2022.102288] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 12/02/2022] Open
Abstract
Mechanistic target of rapamycin complex 2 (mTORC2) is a multi-subunit kinase complex, central to multiple essential signaling pathways. Two core subunits, Rictor and mSin1, distinguish it from the related mTORC1 and support context-dependent phosphorylation of its substrates. mTORC2 structures have been determined previously; however, important questions remain, particularly regarding the structural determinants mediating substrate specificity and context-dependent activity. Here, we used cryo-EM to obtain high-resolution structures of the human mTORC2 apo-complex in the presence of substrates Akt and SGK1. Using functional assays, we then tested predictions suggested by substrate-induced structural changes in mTORC2. For the first time, we visualized in the apo-state the side chain interactions between Rictor and mTOR that sterically occlude recruitment of mTORC1 substrates and confer resistance to the mTORC1 inhibitor rapamycin. Also in the apo-state, we observed that mSin1 formed extensive contacts with Rictor via a pair of short α-helices nestled between two Rictor helical repeat clusters, as well as by an extended strand that makes multiple weak contacts with Rictor helical cluster 1. In co-complex structures, we found that SGK1, but not Akt, markedly altered the conformation of the mSin1 N-terminal extended strand, disrupting multiple weak interactions while inducing a large rotation of mSin1 residue Arg-83, which then interacts with a patch of negatively charged residues within Rictor. Finally, we demonstrate mutation of Arg-83 to Ala selectively disrupts mTORC2-dependent phosphorylation of SGK1, but not of Akt, supporting context-dependent substrate selection. These findings provide new structural and functional insights into mTORC2 specificity and context-dependent activity.
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Affiliation(s)
- Zanlin Yu
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Junliang Chen
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Enzo Takagi
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Feng Wang
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Bidisha Saha
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Xi Liu
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Lydia-Marie Joubert
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California, USA
| | - Catherine E Gleason
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Mingliang Jin
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Chengmin Li
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Carlos Nowotny
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - David Agard
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA; Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California, USA
| | - David Pearce
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA.
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Kuehlmann B, Zucal I, Bonham CA, Joubert LM, Prantl L. SEM and TEM for identification of capsular fibrosis and cellular behavior around breast implants - a descriptive analysis. BMC Mol Cell Biol 2021; 22:25. [PMID: 33941075 PMCID: PMC8091552 DOI: 10.1186/s12860-021-00364-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/15/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Capsular fibrosis (CF) is the most common long-term complication in implant-based breast augmentation. It is well accepted that the foreign body response (FBR) instigates the development of fibrotic disease. Our study aims to compare murine and human samples of CF and describe the cellular and extracellular matrix (ECM) composition using scanning and transmission electron microscopy (SEM and TEM). RESULTS Miniature microtextured silicone breast implants were implanted in mice and subsequently harvested at days 15, 30, and 90 post-operation. Isolated human capsules with the most aggravated form of CF (Baker IV) were harvested post-operation. Both were analyzed with SEM and TEM to assess cellular infiltration and ECM structure. An architectural shift of collagen fiber arrangement from unidirectional to multidirectional was observed at day 90 when compared to days 15 and 30. Fibrosis was observed with an increase of histiocytic infiltration. Moreover, bacterial accumulation was seen around silicone fragments. These findings were common in both murine and human capsules. CONCLUSIONS This murine model accurately recapitulates CF found in humans and can be utilized for future research on cellular invasion in capsular fibrosis. This descriptive study helps to gain a better understanding of cellular mechanisms involved in the FBR. Increases of ECM and cellularity were observed over time with SEM and TEM analysis.
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Affiliation(s)
- Britta Kuehlmann
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University, Stanford, CA, 94305, USA. .,University Center for Plastic, Reconstructive, Aesthetic and Hand Surgery, University Hospital Regensburg and Caritas Hospital St. Josef, 93053, Regensburg, Germany.
| | - Isabel Zucal
- University Center for Plastic, Reconstructive, Aesthetic and Hand Surgery, University Hospital Regensburg and Caritas Hospital St. Josef, 93053, Regensburg, Germany
| | - Clark Andrew Bonham
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University, Stanford, CA, 94305, USA
| | | | - Lukas Prantl
- University Center for Plastic, Reconstructive, Aesthetic and Hand Surgery, University Hospital Regensburg and Caritas Hospital St. Josef, 93053, Regensburg, Germany
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Chang E, Patel C, Young CJ, Flores TA, Joubert LM, Zeng Y, Sinclair R, Gambhir S. Abstract 6258: Combining the glioblastoma cell membrane-permeabilizing effect of tumor treating fields with chemotherapy. Cancer Res 2020. [DOI: 10.1158/1538-7445.am2020-6258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
BACKGROUND Glioblastoma (GBM) is the most lethal primary brain cancer (median survival: 15-17 months, 5-year survival: 5.6%). Standard interventions consist of aggressive surgical resection, radiotherapy, and chemotherapy; however, GBM is heterogeneous and present therapies are ineffective. Tumor treating fields (TTFields) is a form of alternating electric field therapy that has been shown to prolong survival in patients with newly-diagnosed GBM when combined with standard chemotherapy. The mechanism of TTFields' potentiation of standard chemotherapy against GBM is not well understood. We hypothesized that TTFields increases access of chemotherapy to cancer cells by disrupting the cell membrane.
METHODS Human and murine GBM cells (GBM2, GBM39, U87-MG, KR158B) were isolated from primary gliomas. Cells were engineered to stably express firefly or renilla luciferase (fLuc or rLuc, respectively). Cells were either exposed to TTFields (50-500 kHz, 1-4 V/cm) or control conditions. Proliferation was assessed by bioluminescence imaging (BLI) and cell counting. Dextran-FITC binding and influx of 5-aminolevulinic acid (5-ALA) were also assessed. Scanning electron microscopy (SEM) studies were used to probe effects on cellular membranes. All experiments were performed in at least triplicate and 2-way ANOVA or univariate Mann-Whitney test was performed to compare the groups.
RESULTS TTFields significantly inhibited growth of cells (p≤0.02, no TTFields vs. TTFields). BLI suggested alterations in membrane configuration when cancer cells were exposed to TTFields. This was validated with observations of greater fluorescence of membrane-associating Dextran-FITC to U87-MG cells that were subjected to TTFields (p< 0.01, no TTFields vs. TTFields). In GBM39 cells, the optimal effect by TTFields on enhancing Dextran-FITC binding occurred in the range of 100-300 kHz (p<0.02, no TTFields vs. TTFields). TTFields also enhanced 5-ALA uptake into exposed GBM cells (p<0.001, no TTFields vs. TTFields). SEM revealed significantly greater and larger number of holes on the membrane surface of TTFields-exposed U87-MG cancer cells (53.5±19.1 holes per field of view and mean size=240.6±91.7 nm2) compared to unexposed cells (23.9±11.0 holes per field of view and mean size=129.8±31.9 nm2, p< 0.005: TTFields exposed vs. non-exposed). Morphologically, GBM cells unexposed to TTFields had matted and elongated projections from the cell membrane, which were replaced by short, bulbous, bleb-like structures upon TTFields exposure. All observed effects were reversed upon cessation of TTFields.
CONCLUSION The findings suggest a permeabilization of the GBM cell membrane upon exposure to TTFields. This may explain the previously observed synergy between TTFields and standard (e.g., temozolomide) and emerging (Withaferin A) therapies, whereby increased permeability on membranes confers greater accessibility to drugs. Such a strategy is thus a promising candidate for future clinical translation in glioblastoma.
Citation Format: Edwin Chang, Chirag Patel, Caroline J. Young, Thomas Anthony Flores, Lydia-Marie Joubert, Yitian Zeng, Robert Sinclair, Sanjiv Gambhir. Combining the glioblastoma cell membrane-permeabilizing effect of tumor treating fields with chemotherapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6258.
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9
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Liu J, Kim YS, Richardson CE, Tom A, Ramakrishnan C, Birey F, Katsumata T, Chen S, Wang C, Wang X, Joubert LM, Jiang Y, Wang H, Fenno LE, Tok JBH, Pașca SP, Shen K, Bao Z, Deisseroth K. Genetically targeted chemical assembly of functional materials in living cells, tissues, and animals. Science 2020; 367:1372-1376. [PMID: 32193327 DOI: 10.1126/science.aay4866] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 01/21/2020] [Indexed: 12/30/2022]
Abstract
The structural and functional complexity of multicellular biological systems, such as the brain, are beyond the reach of human design or assembly capabilities. Cells in living organisms may be recruited to construct synthetic materials or structures if treated as anatomically defined compartments for specific chemistry, harnessing biology for the assembly of complex functional structures. By integrating engineered-enzyme targeting and polymer chemistry, we genetically instructed specific living neurons to guide chemical synthesis of electrically functional (conductive or insulating) polymers at the plasma membrane. Electrophysiological and behavioral analyses confirmed that rationally designed, genetically targeted assembly of functional polymers not only preserved neuronal viability but also achieved remodeling of membrane properties and modulated cell type-specific behaviors in freely moving animals. This approach may enable the creation of diverse, complex, and functional structures and materials within living systems.
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Affiliation(s)
- Jia Liu
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Yoon Seok Kim
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | | | - Ariane Tom
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Charu Ramakrishnan
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Fikri Birey
- Department of Psychiatry, Stanford University, Stanford, CA 94305, USA
| | - Toru Katsumata
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Shucheng Chen
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Cheng Wang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley CA 94720, USA
| | - Xiao Wang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility, Stanford University, Stanford, CA 94305, USA
| | - Yuanwen Jiang
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Huiliang Wang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Lief E Fenno
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.,Department of Psychiatry, Stanford University, Stanford, CA 94305, USA
| | - Jeffrey B-H Tok
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Sergiu P Pașca
- Department of Psychiatry, Stanford University, Stanford, CA 94305, USA
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, CA 94305, USA.,Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Zhenan Bao
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA.
| | - Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA. .,Department of Psychiatry, Stanford University, Stanford, CA 94305, USA.,Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
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10
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Sass G, Madigan RT, Joubert LM, Bozzi A, Sayed N, Wu JC, Stevens DA. A Combination of Itraconazole and Amiodarone Is Highly Effective against Trypanosoma cruzi Infection of Human Stem Cell-Derived Cardiomyocytes. Am J Trop Med Hyg 2020; 101:383-391. [PMID: 31219005 DOI: 10.4269/ajtmh.19-0023] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Trypanosoma cruzi is the etiologic agent of Chagas disease (CD), which can result in severe cardiomyopathy. Trypanosoma cruzi is endemic to the Americas, and of particular importance in Latin America. In the United States and other non-endemic countries, rising case numbers have also been observed. The currently used drugs are benznidazole (BNZ) and nifurtimox, which have limited efficacy during chronic infection. We repurposed itraconazole (ICZ), originally an antifungal, in combination with amiodarone (AMD), an antiarrhythmic, with the goal of interfering with T. cruzi infection. Human pluripotent stem cells (hiPSCs) were differentiated into cardiomyocytes (hiPSC-CMs). Vero cells or hiPSC-CMs were infected with T. cruzi trypomastigotes of the II or I strain in the presence of ICZ and/or AMD. After 48 hours, cells were Giemsa stained, and infection and multiplication were evaluated microscopically. Trypanosoma cruzi infection and multiplication were evalutated also by electron microscopy. BNZ was used as a reference compound. Cell metabolism in the presence of test substances was assessed. Itraconazole and AMD showed strain- and dose-dependent interference with T. cruzi infection and multiplication in Vero cells or hiPSC-CMs. Combinations of ICZ and AMD were more effective against T. cruzi than the single substances, or BNZ, without affecting host cell metabolism, and better preserving host cell integrity during infection. Our in vitro data in hiPSC-CMs suggest that a combination of ICZ and AMD might serve as a treatment option for CD in patients, but that different responses due to T. cruzi strain differences have to be taken into account.
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Affiliation(s)
- Gabriele Sass
- California Institute for Medical Research, San Jose, California
| | - Roy T Madigan
- Animal Hospital of Smithson Valley, Spring Branch, Texas
| | - Lydia-Marie Joubert
- EM Unit, Central Analytical Facilities, Stellenbosch University, Stellenbosch, South Africa.,Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Adriana Bozzi
- California Institute for Medical Research, San Jose, California.,Centro de Pesquisas René Rachou, FIOCRUZ, Belo Horizonte, Brazil.,Division of Cardiology, Department of Medicine, School of Medicine, Stanford University, Stanford, California.,School of Medicine, Cardiovascular Institute, Stanford University, Stanford, California
| | - Nazish Sayed
- School of Medicine, Cardiovascular Institute, Stanford University, Stanford, California.,Division of Cardiology, Department of Medicine, School of Medicine, Stanford University, Stanford, California
| | - Joseph C Wu
- School of Medicine, Cardiovascular Institute, Stanford University, Stanford, California.,Division of Cardiology, Department of Medicine, School of Medicine, Stanford University, Stanford, California
| | - David A Stevens
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California.,California Institute for Medical Research, San Jose, California
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11
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SoRelle ED, Yecies DW, Liba O, Bennett FC, Graef CM, Dutta R, Mitra S, Joubert LM, Cheshier S, Grant GA, de la Zerda A. Spatiotemporal Tracking of Brain-Tumor-Associated Myeloid Cells in Vivo through Optical Coherence Tomography with Plasmonic Labeling and Speckle Modulation. ACS Nano 2019; 13:7985-7995. [PMID: 31259527 PMCID: PMC8144904 DOI: 10.1021/acsnano.9b02656] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
By their nature, tumors pose a set of profound challenges to the immune system with respect to cellular recognition and response coordination. Recent research indicates that leukocyte subpopulations, especially tumor-associated macrophages (TAMs), can exert substantial influence on the efficacy of various cancer immunotherapy treatment strategies. To better study and understand the roles of TAMs in determining immunotherapeutic outcomes, significant technical challenges associated with dynamically monitoring single cells of interest in relevant live animal models of solid tumors must be overcome. However, imaging techniques with the requisite combination of spatiotemporal resolution, cell-specific contrast, and sufficient signal-to-noise at increasing depths in tissue are exceedingly limited. Here we describe a method to enable high-resolution, wide-field, longitudinal imaging of TAMs based on speckle-modulating optical coherence tomography (SM-OCT) and spectral scattering from an optimized contrast agent. The approach's improvements to OCT detection sensitivity and noise reduction enabled high-resolution OCT-based observation of individual cells of a specific host lineage in live animals. We found that large gold nanorods (LGNRs) that exhibit a narrow-band, enhanced scattering cross-section can selectively label TAMs and activate microglia in an in vivo orthotopic murine model of glioblastoma multiforme. We demonstrated near real-time tracking of the migration of cells within these myeloid subpopulations. The intrinsic spatiotemporal resolution, imaging depth, and contrast sensitivity reported herein may facilitate detailed studies of the fundamental behaviors of TAMs and other leukocytes at the single-cell level in vivo, including intratumoral distribution heterogeneity and roles in modulating cancer proliferation.
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Affiliation(s)
- Elliott Daniel SoRelle
- Department of Structural Biology, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Biophysics Program, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Molecular Imaging Program (MIPS), Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Bio-X Program, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
| | - Derek William Yecies
- Department of Structural Biology, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Department of Neurosurgery, Division of Pediatric Neurosurgery, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
| | - Orly Liba
- Department of Structural Biology, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Molecular Imaging Program (MIPS), Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Bio-X Program, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Department of Electrical Engineering, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
| | | | - Claus Moritz Graef
- Department of Neurosurgery, Division of Pediatric Neurosurgery, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
| | - Rebecca Dutta
- Department of Structural Biology, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Molecular Imaging Program (MIPS), Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Bio-X Program, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
| | - Siddhartha Mitra
- Department of Neurosurgery, Division of Pediatric Neurosurgery, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Institute for Stem Cell Biology and Regenerative Medicine and the Ludwig Cancer Center, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
| | - Samuel Cheshier
- Department of Neurosurgery, Division of Pediatric Neurosurgery, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Institute for Stem Cell Biology and Regenerative Medicine and the Ludwig Cancer Center, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
| | - Gerald A. Grant
- Department of Neurosurgery, Division of Pediatric Neurosurgery, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Institute for Stem Cell Biology and Regenerative Medicine and the Ludwig Cancer Center, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
| | - Adam de la Zerda
- Department of Structural Biology, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Biophysics Program, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Molecular Imaging Program (MIPS), Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Bio-X Program, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- Department of Electrical Engineering, Stanford University, 299 Campus Dr., Stanford, CA 94305, USA
- The Chan Zuckerberg Biohub, 499 Illinois St., San Francisco, CA 94158, USA
- To whom correspondence should be addressed:
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12
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Prigozhin MB, Maurer PC, Courtis AM, Liu N, Wisser MD, Siefe C, Tian B, Chan E, Song G, Fischer S, Aloni S, Ogletree DF, Barnard ES, Joubert LM, Rao J, Alivisatos AP, Macfarlane RM, Cohen BE, Cui Y, Dionne JA, Chu S. Bright sub-20-nm cathodoluminescent nanoprobes for electron microscopy. Nat Nanotechnol 2019; 14:420-425. [PMID: 30833691 PMCID: PMC6786485 DOI: 10.1038/s41565-019-0395-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 01/28/2019] [Indexed: 05/19/2023]
Abstract
Electron microscopy has been instrumental in our understanding of complex biological systems. Although electron microscopy reveals cellular morphology with nanoscale resolution, it does not provide information on the location of different types of proteins. An electron-microscopy-based bioimaging technology capable of localizing individual proteins and resolving protein-protein interactions with respect to cellular ultrastructure would provide important insights into the molecular biology of a cell. Here, we synthesize small lanthanide-doped nanoparticles and measure the absolute photon emission rate of individual nanoparticles resulting from a given electron excitation flux (cathodoluminescence). Our results suggest that the optimization of nanoparticle composition, synthesis protocols and electron imaging conditions can lead to sub-20-nm nanolabels that would enable high signal-to-noise localization of individual biomolecules within a cellular context. In ensemble measurements, these labels exhibit narrow spectra of nine distinct colours, so the imaging of biomolecules in a multicolour electron microscopy modality may be possible.
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Affiliation(s)
| | - Peter C Maurer
- Department of Physics, Stanford University, Stanford, CA, USA
| | - Alexandra M Courtis
- Department of Chemistry, University of California at Berkeley, Berkeley, CA, USA
| | - Nian Liu
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Michael D Wisser
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Chris Siefe
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Bining Tian
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Emory Chan
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Guosheng Song
- Department of Radiology, Stanford University, Stanford, CA, USA
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China
| | - Stefan Fischer
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Shaul Aloni
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - D Frank Ogletree
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Edward S Barnard
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Lydia-Marie Joubert
- CSIF Beckman Center, Stanford University, Stanford, CA, USA
- EM Unit, Central Analytical Facilities, Stellenbosch University, Stellenbosch, South Africa
| | - Jianghong Rao
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - A Paul Alivisatos
- Department of Chemistry, University of California at Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
- Kavli Energy NanoScience Institute, Berkeley, CA, USA
| | | | - Bruce E Cohen
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Yi Cui
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Jennifer A Dionne
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Steven Chu
- Department of Physics, Stanford University, Stanford, CA, USA.
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA.
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13
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Reichhardt C, Joubert LM, Clemons KV, Stevens DA, Cegelski L. Integration of electron microscopy and solid-state NMR analysis for new views and compositional parameters of Aspergillus fumigatus biofilms. Med Mycol 2019; 57:S239-S244. [PMID: 30816969 DOI: 10.1093/mmy/myy140] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/25/2018] [Accepted: 12/24/2018] [Indexed: 12/14/2022] Open
Abstract
The general ability and tendency of bacteria and fungi to assemble into bacterial communities, termed biofilms, poses unique challenges to the treatment of human infections. Fungal biofilms, in particular, are associated with enhanced virulence in vivo and decreased sensitivity to antifungals. Much attention has been given to the complex cell wall structures in fungal organisms, yet beyond the cell surface, Aspergillus fumigatus and other fungi assemble a self-secreted extracellular matrix that is the hallmark of the biofilm lifestyle, protecting and changing the environment of resident members. Elucidation of the chemical and molecular detail of the extracellular matrix is crucial to understanding how its structure contributes to persistence and antifungal resistance in the host. We present a summary of integrated analyses of A. fumigatus biofilm architecture, including hyphae and the extracellular matrix, by scanning electron microscopy and A. fumigatus matrix composition by new top-down solid-state NMR approaches coupled with biochemical analysis. This combined methodology will be invaluable in formulating quantitative and chemical comparisons of A. fumigatus isolates that differ in virulence and are more or less resistant to antifungals. Ultimately, knowledge of the chemical and molecular requirements for matrix formation and function will drive the identification and development of new strategies to interfere with biofilm formation and virulence.
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Affiliation(s)
- Courtney Reichhardt
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - Lydia-Marie Joubert
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Karl V Clemons
- California Institute for Medical Research, San Jose, California USA.,Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
| | - David A Stevens
- California Institute for Medical Research, San Jose, California USA.,Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
| | - Lynette Cegelski
- Department of Chemistry, Stanford University, Stanford, California USA
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14
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Chang E, Patel CB, Pohling C, Young C, Song J, Flores TA, Zeng Y, Joubert LM, Arami H, Natarajan A, Sinclair R, Gambhir SS. Tumor treating fields increases membrane permeability in glioblastoma cells. Cell Death Discov 2018; 4:113. [PMID: 30534421 PMCID: PMC6281619 DOI: 10.1038/s41420-018-0130-x] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/08/2018] [Accepted: 11/12/2018] [Indexed: 01/04/2023] Open
Abstract
Glioblastoma is the most common yet most lethal of primary brain cancers with a one-year post-diagnosis survival rate of 65% and a five-year survival rate of barely 5%. Recently the U.S. Food and Drug Administration approved a novel fourth approach (in addition to surgery, radiation therapy, and chemotherapy) to treating glioblastoma; namely, tumor treating fields (TTFields). TTFields involves the delivery of alternating electric fields to the tumor but its mechanisms of action are not fully understood. Current theories involve TTFields disrupting mitosis due to interference with proper mitotic spindle assembly. We show that TTFields also alters cellular membrane structure thus rendering it more permeant to chemotherapeutics. Increased membrane permeability through the imposition of TTFields was shown by several approaches. For example, increased permeability was indicated through increased bioluminescence with TTFields exposure or with the increased binding and ingress of membrane-associating reagents such as Dextran-FITC or ethidium D or with the demonstration by scanning electron microscopy of augmented number and sizes of holes on the cellular membrane. Further investigations showed that increases in bioluminescence and membrane hole production with TTFields exposure disappeared by 24 h after cessation of alternating electric fields thus demonstrating that this phenomenom is reversible. Preliminary investigations showed that TTFields did not induce membrane holes in normal human fibroblasts thus suggesting that the phenomenom was specific to cancer cells. With TTFields, we present evidence showing augmented membrane accessibility by compounds such as 5-aminolevulinic acid, a reagent used intraoperatively to delineate tumor from normal tissue in glioblastoma patients. In addition, this mechanism helps to explain previous reports of additive and synergistic effects between TTFields and other chemotherapies. These findings have implications for the design of combination therapies in glioblastoma and other cancers and may significantly alter standard of care strategies for these diseases.
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Affiliation(s)
- Edwin Chang
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, Room E150, 318 Campus Drive West, Stanford, CA 94305 USA
| | - Chirag B. Patel
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, Room E150, 318 Campus Drive West, Stanford, CA 94305 USA
- Division of Neuro-Oncology, Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Christoph Pohling
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, Room E150, 318 Campus Drive West, Stanford, CA 94305 USA
| | - Caroline Young
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, Room E150, 318 Campus Drive West, Stanford, CA 94305 USA
| | - Jonathan Song
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, Room E150, 318 Campus Drive West, Stanford, CA 94305 USA
| | - Thomas Anthony Flores
- Department of Applied Physics, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Yitian Zeng
- Department of Materials Science & Engineering, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Lydia-Marie Joubert
- Electron Microscopy Unit, Stellenbosch University, Stellenbosch, South Africa
| | - Hamed Arami
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, Room E150, 318 Campus Drive West, Stanford, CA 94305 USA
| | - Arutselvan Natarajan
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, Room E150, 318 Campus Drive West, Stanford, CA 94305 USA
| | - Robert Sinclair
- Department of Materials Science & Engineering, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Sanjiv S. Gambhir
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, Room E150, 318 Campus Drive West, Stanford, CA 94305 USA
- Department of Materials Science & Engineering, Stanford University School of Medicine, Stanford, CA 94305 USA
- Department of Bioengineering, Stanford University School of Medicine, Stanford, CA 94305 USA
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15
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Tsai JM, Sinha R, Seita J, Fernhoff N, Christ S, Koopmans T, Krampitz GW, McKenna KM, Xing L, Sandholzer M, Sales JH, Shoham M, McCracken M, Joubert LM, Gordon SR, Poux N, Wernig G, Norton JA, Weissman IL, Rinkevich Y. Surgical adhesions in mice are derived from mesothelial cells and can be targeted by antibodies against mesothelial markers. Sci Transl Med 2018; 10:eaan6735. [PMID: 30487249 DOI: 10.1126/scitranslmed.aan6735] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [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] [Received: 05/16/2017] [Revised: 09/26/2017] [Accepted: 04/30/2018] [Indexed: 11/20/2023]
Abstract
Peritoneal adhesions are fibrous tissues that tether organs to one another or to the peritoneal wall and are a major cause of postsurgical and infectious morbidity. The primary molecular chain of events leading to the initiation of adhesions has been elusive, chiefly due to the lack of an identifiable cell of origin. Using clonal analysis and lineage tracing, we have identified injured surface mesothelium expressing podoplanin (PDPN) and mesothelin (MSLN) as a primary instigator of peritoneal adhesions after surgery in mice. We demonstrate that an anti-MSLN antibody diminished adhesion formation in a mouse model where adhesions were induced by surgical ligation to form ischemic buttons and subsequent surgical abrasion of the peritoneum. RNA sequencing and bioinformatics analyses of mouse mesothelial cells from injured mesothelium revealed aspects of the pathological mechanism of adhesion development and yielded several potential regulators of this process. Specifically, we show that PDPN+MSLN+ mesothelium responded to hypoxia by early up-regulation of hypoxia-inducible factor 1 alpha (HIF1α) that preceded adhesion development. Inhibition of HIF1α with small molecules ameliorated the injury program in damaged mesothelium and was sufficient to diminish adhesion severity in a mouse model. Analyses of human adhesion tissue suggested that similar surface markers and signaling pathways may contribute to surgical adhesions in human patients.
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Affiliation(s)
- Jonathan M Tsai
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Rahul Sinha
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jun Seita
- AI based Healthcare and Medical Data Analysis Standardization Unit, Medical Sciences Innovation Hub Program, RIKEN, Tokyo 103-0027, Japan
| | - Nathaniel Fernhoff
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Simon Christ
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease,Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Tim Koopmans
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease,Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Geoffrey W Krampitz
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of General Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kelly M McKenna
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Liujing Xing
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Michael Sandholzer
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease,Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Jennifer Horatia Sales
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease,Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Maia Shoham
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Melissa McCracken
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility, Beckman Center, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sydney R Gordon
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nicolas Poux
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gerlinde Wernig
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jeffrey A Norton
- Department of General Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Irving L Weissman
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Ludwig Center for Cancer Stem Cell Biology and Medicine at Stanford University, Stanford, CA 94305, USA
| | - Yuval Rinkevich
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease,Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany.
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16
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Liu Q, Zhang Y, Peng CS, Yang T, Joubert LM, Chu S. Single upconversion nanoparticle imaging at sub-10 W cm -2 irradiance. Nat Photonics 2018; 12:548-553. [PMID: 31258619 PMCID: PMC6599589 DOI: 10.1038/s41566-018-0217-1] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 06/28/2018] [Indexed: 05/19/2023]
Abstract
Lanthanide-doped upconversion nanoparticles (UCNPs) are promising single-molecule probes given their non-blinking, photobleach-resistant luminescence upon infrared excitation. However, the weak luminescence of sub-50 nm UCNPs limits their single-particle detection to above 10 kWcm-2 that is impractical for live cell imaging. Here, we systematically characterize single-particle luminescence for UCNPs with various formulations over a 106 variation in incident power, down to 8 Wcm-2. A core-shell-shell (CSS) structure (NaYF4@NaYb1-xF4:Erx@NaYF4) is shown to be significantly brighter than the commonly used NaY0.78F4:Yb0.2Er0.02. At 8 Wcm-2, the 8% Er3+ CSS particles exhibit a 150-fold enhancement given their high sensitizer Yb3+ content and the presence of an inert shell to prevent energy migration to defects. Moreover, we reveal power-dependent luminescence enhancement from the inert shell, which explains the discrepancy in enhancement factors reported by ensemble and previous single-particle measurements. These brighter probes open the possibility of cellular and single-molecule tracking at low irradiance.
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Affiliation(s)
- Qian Liu
- Department of Physics, Stanford University, Stanford, California 94305, United States
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, United States
| | - Yunxiang Zhang
- Department of Physics, Stanford University, Stanford, California 94305, United States
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, United States
| | - Chunte Sam Peng
- Department of Physics, Stanford University, Stanford, California 94305, United States
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, United States
| | - Tianshe Yang
- Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, 210023, P. R. China
| | - Lydia-Marie Joubert
- CSIF Beckman Center, Stanford University, Stanford, California 94305, United States
| | - Steven Chu
- Department of Physics, Stanford University, Stanford, California 94305, United States
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, United States
- Correspondence and requests for materials should be addressed to S.C.
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17
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Li Y, Li Y, Pei A, Yan K, Sun Y, Wu CL, Joubert LM, Chin R, Koh AL, Yu Y, Perrino J, Butz B, Chu S, Cui Y. Atomic structure of sensitive battery materials and interfaces revealed by cryo-electron microscopy. Science 2018; 358:506-510. [PMID: 29074771 DOI: 10.1126/science.aam6014] [Citation(s) in RCA: 388] [Impact Index Per Article: 64.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 09/14/2017] [Indexed: 01/19/2023]
Abstract
Whereas standard transmission electron microscopy studies are unable to preserve the native state of chemically reactive and beam-sensitive battery materials after operation, such materials remain pristine at cryogenic conditions. It is then possible to atomically resolve individual lithium metal atoms and their interface with the solid electrolyte interphase (SEI). We observe that dendrites in carbonate-based electrolytes grow along the <111> (preferred), <110>, or <211> directions as faceted, single-crystalline nanowires. These growth directions can change at kinks with no observable crystallographic defect. Furthermore, we reveal distinct SEI nanostructures formed in different electrolytes.
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Affiliation(s)
- Yuzhang Li
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Yanbin Li
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Allen Pei
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Kai Yan
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Yongming Sun
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Chun-Lan Wu
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Richard Chin
- Stanford Nano Shared Facility, Stanford University, Stanford, CA 94305, USA
| | - Ai Leen Koh
- Stanford Nano Shared Facility, Stanford University, Stanford, CA 94305, USA
| | - Yi Yu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - John Perrino
- Cell Sciences Imaging Facility, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Benjamin Butz
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.,Institut für Werkstofftechnik and Gerätezentrum für Mikro- und Nanoanalytik (MNaF), Universität Siegen, 57068 Siegen, Germany
| | - Steven Chu
- Department of Physics, Stanford University, Stanford, CA 94305, USA.,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yi Cui
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA. .,Stanford Institute for Materials and Energy Sciences, Stanford Linear Accelerator Center (SLAC) National Accelerator Laboratory, Menlo Park, CA 94025, USA
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18
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Nazik H, Joubert LM, Secor PR, Sweere JM, Bollyky PL, Sass G, Cegelski L, Stevens DA. Pseudomonas phage inhibition of Candida albicans. Microbiology (Reading) 2017; 163:1568-1577. [PMID: 28982395 DOI: 10.1099/mic.0.000539] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pseudomonas aeruginosa (Pa) and Candida albicans (Ca) are major bacterial and fungal pathogens in immunocompromised hosts, and notably in the airways of cystic fibrosis patients. The bacteriophages of Pa physically alter biofilms, and were recently shown to inhibit the biofilms of Aspergillus fumigatus. To understand the range of this viral-fungal interaction, we studied Pa phages Pf4 and Pf1, and their interactions with Ca biofilm formation and preformed Ca biofilm. Both forms of Ca biofilm development, as well as planktonic Ca growth, were inhibited by either phage. The inhibition of biofilm was reversed by the addition of iron, suggesting that the mechanism of phage action on Ca involves denial of iron. Birefringence studies on added phage showed an ordered structure of binding to Ca. Electron microscopic observations indicated phage aggregation in the biofilm extracellular matrix. Bacteriophage-fungal interactions may be a general feature with several pathogens in the fungal kingdom.
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Affiliation(s)
- Hasan Nazik
- Division of Infectious Diseases, Department of Medicine, Stanford University Medical School, Stanford, CA, USA.,California Institute for Medical Research, San Jose, CA, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility, Stanford University Medical School, Stanford, CA, USA
| | - Patrick R Secor
- Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Johanna M Sweere
- Division of Infectious Diseases, Department of Medicine, Stanford University Medical School, Stanford, CA, USA.,Immunology Program, Stanford University, Stanford, CA, USA
| | - Paul L Bollyky
- Division of Infectious Diseases, Department of Medicine, Stanford University Medical School, Stanford, CA, USA.,Immunology Program, Stanford University, Stanford, CA, USA
| | - Gabriele Sass
- California Institute for Medical Research, San Jose, CA, USA.,Division of Infectious Diseases, Department of Medicine, Stanford University Medical School, Stanford, CA, USA
| | | | - David A Stevens
- California Institute for Medical Research, San Jose, CA, USA.,Division of Infectious Diseases, Department of Medicine, Stanford University Medical School, Stanford, CA, USA
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19
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Santoro F, Zhao W, Joubert LM, Duan L, Schnitker J, van de Burgt Y, Lou HY, Liu B, Salleo A, Cui L, Cui Y, Cui B. Revealing the Cell-Material Interface with Nanometer Resolution by Focused Ion Beam/Scanning Electron Microscopy. ACS Nano 2017; 11:8320-8328. [PMID: 28682058 PMCID: PMC5806611 DOI: 10.1021/acsnano.7b03494] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The interface between cells and nonbiological surfaces regulates cell attachment, chronic tissue responses, and ultimately the success of medical implants or biosensors. Clinical and laboratory studies show that topological features of the surface profoundly influence cellular responses; for example, titanium surfaces with nano- and microtopographical structures enhance osteoblast attachment and host-implant integration as compared to a smooth surface. To understand how cells and tissues respond to different topographical features, it is of critical importance to directly visualize the cell-material interface at the relevant nanometer length scale. Here, we present a method for in situ examination of the cell-to-material interface at any desired location, based on focused ion beam milling and scanning electron microscopy imaging to resolve the cell membrane-to-material interface with 10 nm resolution. By examining how cell membranes interact with topographical features such as nanoscale protrusions or invaginations, we discovered that the cell membrane readily deforms inward and wraps around protruding structures, but hardly deforms outward to contour invaginating structures. This asymmetric membrane response (inward vs outward deformation) causes the cleft width between the cell membrane and the nanostructure surface to vary by more than an order of magnitude. Our results suggest that surface topology is a crucial consideration for the development of medical implants or biosensors whose performances are strongly influenced by the cell-to-material interface. We anticipate that the method can be used to explore the direct interaction of cells/tissue with medical devices such as metal implants in the future.
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Affiliation(s)
- Francesca Santoro
- Department of Chemistry, Stanford University, Stanford, CA94305, USA
- Correspondence to: ,
| | - Wenting Zhao
- Department of Chemistry, Stanford University, Stanford, CA94305, USA
- Department of Material Science and Engineering, Stanford University, Stanford, CA94305, USA
| | | | - Liting Duan
- Department of Chemistry, Stanford University, Stanford, CA94305, USA
| | - Jan Schnitker
- Institute of Bioelectronics ICS/PGI-8, Forschungszentrum Juelich, Juelich, 52428, Germany
| | - Yoeri van de Burgt
- Department of Material Science and Engineering, Stanford University, Stanford, CA94305, USA
| | - Hsin-Ya Lou
- Department of Chemistry, Stanford University, Stanford, CA94305, USA
| | - Bofei Liu
- Department of Material Science and Engineering, Stanford University, Stanford, CA94305, USA
| | - Alberto Salleo
- Department of Material Science and Engineering, Stanford University, Stanford, CA94305, USA
| | - Lifeng Cui
- Department of Material Science and Engineering, Dongguan University of Technology, Guangdong 523808, China
| | - Yi Cui
- Department of Material Science and Engineering, Stanford University, Stanford, CA94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator, Menlo Park, CA94025, USA
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, Stanford, CA94305, USA
- Correspondence to: ,
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20
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Hayer A, Shao L, Chung M, Joubert LM, Yang HW, Tsai FC, Bisaria A, Betzig E, Meyer T. Engulfed cadherin fingers are polarized junctional structures between collectively migrating endothelial cells. Nat Cell Biol 2016; 18:1311-1323. [PMID: 27842057 DOI: 10.1038/ncb3438] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 10/11/2016] [Indexed: 12/11/2022]
Abstract
The development and maintenance of tissues requires collective cell movement, during which neighbouring cells coordinate the polarity of their migration machineries. Here, we ask how polarity signals are transmitted from one cell to another across symmetrical cadherin junctions, during collective migration. We demonstrate that collectively migrating endothelial cells have polarized VE-cadherin-rich membrane protrusions, 'cadherin fingers', which leading cells extend from their rear and follower cells engulf at their front, thereby generating opposite membrane curvatures and asymmetric recruitment of curvature-sensing proteins. In follower cells, engulfment of cadherin fingers occurs along with the formation of a lamellipodia-like zone with low actomyosin contractility, and requires VE-cadherin/catenin complexes and Arp2/3-driven actin polymerization. Lateral accumulation of cadherin fingers in follower cells precedes turning, and increased actomyosin contractility can initiate cadherin finger extension as well as engulfment by a neighbouring cell, to promote follower behaviour. We propose that cadherin fingers serve as guidance cues that direct collective cell migration.
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Affiliation(s)
- Arnold Hayer
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Lin Shao
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, USA
| | - Mingyu Chung
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Hee Won Yang
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Feng-Chiao Tsai
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Anjali Bisaria
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Eric Betzig
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, USA
| | - Tobias Meyer
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305, USA
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21
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Shudo Y, Cohen JE, Goldstone AB, MacArthur JW, Patel J, Edwards BB, Hopkins MS, Steele AN, Joubert LM, Miyagawa S, Sawa Y, Woo YJ. Isolation and trans-differentiation of mesenchymal stromal cells into smooth muscle cells: Utility and applicability for cell-sheet engineering. Cytotherapy 2016; 18:510-7. [PMID: 26971679 DOI: 10.1016/j.jcyt.2016.01.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 01/04/2016] [Accepted: 01/23/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND Bone marrow (BM)-derived mesenchymal stromal cells (MSCs) have shown potential to differentiate into various cell types, including smooth muscle cells (SMCs). The extracellular matrix (ECM) represents an appealing and readily available source of SMCs for use in tissue engineering. In this study, we hypothesized that the ECM could be used to induce MSC differentiation to SMCs for engineered cell-sheet construction. METHODS Primary MSCs were isolated from the BM of Wistar rats, transferred and cultured on dishes coated with 3 different types of ECM: collagen type IV (Col IV), fibronectin (FN), and laminin (LM). Primary MSCs were also included as a control. The proportions of SMC (a smooth muscle actin [aSMA] and SM22a) and MSC markers were examined with flow cytometry and Western blotting, and cell proliferation rates were also quantified. RESULTS Both FN and LM groups were able to induce differentiation of MSCs toward smooth muscle-like cell types, as evidenced by an increase in the proportion of SMC markers (aSMA; Col IV 42.3 ± 6.9%, FN 65.1 ± 6.5%, LM 59.3 ± 7.0%, Control 39.9 ± 3.1%; P = 0.02, SM22; Col IV 56.0 ± 7.7%, FN 74.2 ± 6.7%, LM 60.4 ± 8.7%, Control 44.9 ± 3.6%) and a decrease in that of MSC markers (CD105: Col IV 64.0 ± 5.2%, FN 57.6 ± 4.0%, LM 60.3 ± 7.0%, Control 85.3 ± 4.2%; P = 0.03). The LM group showed a decrease in overall cell proliferation, whereas FN and Col IV groups remained similar to control MSCs (Col IV, 9.0 ± 2.3%; FN, 9.8 ± 2.5%; LM, 4.3 ± 1.3%; Control, 9.8 ± 2.8%). CONCLUSIONS Our findings indicate that ECM selection can guide differentiation of MSCs into the SMC lineage. Fibronectin preserved cellular proliferative capacity while yielding the highest proportion of differentiated SMCs, suggesting that FN-coated materials may be facilitate smooth muscle tissue engineering.
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Affiliation(s)
- Yasuhiro Shudo
- Department of Cardiothoracic Surgery, School of Medicine, Stanford University, Stanford, CA, USA; Department of Cardiovascular Surgery, School of Medicine, Osaka University Graduate, Osaka, Japan
| | - Jeffrey E Cohen
- Department of Cardiothoracic Surgery, School of Medicine, Stanford University, Stanford, CA, USA
| | - Andrew B Goldstone
- Department of Cardiothoracic Surgery, School of Medicine, Stanford University, Stanford, CA, USA
| | - John W MacArthur
- Department of Cardiothoracic Surgery, School of Medicine, Stanford University, Stanford, CA, USA
| | - Jay Patel
- Department of Cardiothoracic Surgery, School of Medicine, Stanford University, Stanford, CA, USA
| | - Bryan B Edwards
- Department of Cardiothoracic Surgery, School of Medicine, Stanford University, Stanford, CA, USA
| | - Michael S Hopkins
- Department of Cardiothoracic Surgery, School of Medicine, Stanford University, Stanford, CA, USA
| | - Amanda N Steele
- Department of Cardiothoracic Surgery, School of Medicine, Stanford University, Stanford, CA, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Shigeru Miyagawa
- Department of Cardiovascular Surgery, School of Medicine, Osaka University Graduate, Osaka, Japan
| | - Yoshiki Sawa
- Department of Cardiovascular Surgery, School of Medicine, Osaka University Graduate, Osaka, Japan
| | - Y Joseph Woo
- Department of Cardiothoracic Surgery, School of Medicine, Stanford University, Stanford, CA, USA.
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22
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Joubert LM, Ferreira JA, Stevens DA, Nazik H, Cegelski L. Visualization of Aspergillus fumigatus biofilms with Scanning Electron Microscopy and Variable Pressure-Scanning Electron Microscopy: A comparison of processing techniques. J Microbiol Methods 2016; 132:46-55. [PMID: 27836634 DOI: 10.1016/j.mimet.2016.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/06/2016] [Accepted: 11/06/2016] [Indexed: 12/21/2022]
Abstract
Aspergillus fumigatus biofilms consist of a three-dimensional network of cellular hyphae and extracellular matrix. They are involved in infections of immune-compromised individuals, particularly those with cystic fibrosis. These structures are associated with persistence of infection, resistance to host immunity, and antimicrobial resistance. Thorough understanding of structure and function is imperative in the design of therapeutic drugs. Optimization of processing parameters, including aldehyde fixation, heavy metal contrasting, drying techniques and Ionic Liquid treatment, was undertaken for an ultrastructural approach to understand cellular and extracellular biofilm components. Conventional and Variable Pressure Scanning Electron Microscopy were applied to analyze the structure of biofilms attached to plastic and formed at an air-liquid interface.
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Affiliation(s)
- Lydia-Marie Joubert
- Cell Sciences Imaging Facility, Stanford University School of Medicine, Stanford, CA, USA.
| | - Jose Ag Ferreira
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA; California Institute for Medical Research, San Jose, CA, USA
| | - David A Stevens
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA; California Institute for Medical Research, San Jose, CA, USA
| | - Hasan Nazik
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA; California Institute for Medical Research, San Jose, CA, USA
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23
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Penner JC, Ferreira JAG, Secor PR, Sweere JM, Birukova MK, Joubert LM, Haagensen JAJ, Garcia O, Malkovskiy AV, Kaber G, Nazik H, Manasherob R, Spormann AM, Clemons KV, Stevens DA, Bollyky PL. Pf4 bacteriophage produced by Pseudomonas aeruginosa inhibits Aspergillus fumigatus metabolism via iron sequestration. Microbiology (Reading) 2016; 162:1583-1594. [PMID: 27473221 DOI: 10.1099/mic.0.000344] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) are major human pathogens known to interact in a variety of disease settings, including airway infections in cystic fibrosis. We recently reported that clinical CF isolates of Pa inhibit the formation and growth of Af biofilms. Here, we report that the bacteriophage Pf4, produced by Pa, can inhibit the metabolic activity of Af biofilms. This phage-mediated inhibition was dose dependent, ablated by phage denaturation, and was more pronounced against preformed Af biofilm rather than biofilm formation. In contrast, planktonic conidial growth was unaffected. Two other phages, Pf1 and fd, did not inhibit Af, nor did supernatant from a Pa strain incapable of producing Pf4. Pf4, but not Pf1, attaches to Af hyphae in an avid and prolonged manner, suggesting that Pf4-mediated inhibition of Af may occur at the biofilm surface. We show that Pf4 binds iron, thus denying Af a crucial resource. Consistent with this, the inhibition of Af metabolism by Pf4 could be overcome with supplemental ferric iron, with preformed biofilm more resistant to reversal. To our knowledge, this is the first report of a bacterium producing a phage that inhibits the growth of a fungus and the first description of a phage behaving as an iron chelator in a biological system.
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Affiliation(s)
- Jack C Penner
- California Institute for Medical Research, San Jose, CA, USA.,Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Jose A G Ferreira
- California Institute for Medical Research, San Jose, CA, USA.,Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Patrick R Secor
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Johanna M Sweere
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA.,Stanford Immunology Program, Stanford University, Stanford, CA, USA
| | - Maria K Birukova
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA.,Stanford Immunology Program, Stanford University, Stanford, CA, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility (CSIF), Stanford University Medical School, Stanford, CA, USA
| | - Janus A J Haagensen
- Department of Civil & Environmental Engineering, Stanford University, Stanford, CA, USA
| | - Omar Garcia
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Andrey V Malkovskiy
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA.,Biomaterial and Advanced Drug Delivery Laboratory, Stanford University, Stanford, CA 94305, USA
| | - Gernot Kaber
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Hasan Nazik
- California Institute for Medical Research, San Jose, CA, USA.,Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA.,Department of Medical Microbiology, Istanbul University, Istanbul, Turkey
| | - Robert Manasherob
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Alfred M Spormann
- Department of Civil & Environmental Engineering, Stanford University, Stanford, CA, USA
| | - Karl V Clemons
- California Institute for Medical Research, San Jose, CA, USA.,Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - David A Stevens
- California Institute for Medical Research, San Jose, CA, USA.,Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - Paul L Bollyky
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University, Stanford, CA, USA.,Stanford Immunology Program, Stanford University, Stanford, CA, USA
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24
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Reichhardt C, Ferreira JAG, Joubert LM, Clemons KV, Stevens DA, Cegelski L. Analysis of the Aspergillus fumigatus Biofilm Extracellular Matrix by Solid-State Nuclear Magnetic Resonance Spectroscopy. Eukaryot Cell 2015; 14:1064-72. [PMID: 26163318 PMCID: PMC4621319 DOI: 10.1128/ec.00050-15] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/06/2015] [Indexed: 11/20/2022]
Abstract
Aspergillus fumigatus is commonly responsible for lethal fungal infections among immunosuppressed individuals. A. fumigatus forms biofilm communities that are of increasing biomedical interest due to the association of biofilms with chronic infections and their increased resistance to antifungal agents and host immune factors. Understanding the composition of microbial biofilms and the extracellular matrix is important to understanding function and, ultimately, to developing strategies to inhibit biofilm formation. We implemented a solid-state nuclear magnetic resonance (NMR) approach to define compositional parameters of the A. fumigatus extracellular matrix (ECM) when biofilms are formed in RPMI 1640 nutrient medium. Whole biofilm and isolated matrix networks were also characterized by electron microscopy, and matrix proteins were identified through protein gel analysis. The (13)C NMR results defined and quantified the carbon contributions in the insoluble ECM, including carbonyls, aromatic carbons, polysaccharide carbons (anomeric and nonanomerics), aliphatics, etc. Additional (15)N and (31)P NMR spectra permitted more specific annotation of the carbon pools according to C-N and C-P couplings. Together these data show that the A. fumigatus ECM produced under these growth conditions contains approximately 40% protein, 43% polysaccharide, 3% aromatic-containing components, and up to 14% lipid. These fundamental chemical parameters are needed to consider the relationships between composition and function in the A. fumigatus ECM and will enable future comparisons with other organisms and with A. fumigatus grown under alternate conditions.
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Affiliation(s)
| | - Jose A G Ferreira
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA California Institute for Medical Research, San Jose, California, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility, Stanford University School of Medicine, Stanford, California, USA
| | - Karl V Clemons
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA California Institute for Medical Research, San Jose, California, USA
| | - David A Stevens
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA California Institute for Medical Research, San Jose, California, USA
| | - Lynette Cegelski
- Department of Chemistry, Stanford University, Stanford, California, USA
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25
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Farnebo S, Woon CY, Schmitt T, Joubert LM, Kim M, Pham H, Chang J. Design and Characterization of an Injectable Tendon Hydrogel: A Novel Scaffold for Guided Tissue Regeneration in the Musculoskeletal System. Tissue Eng Part A 2014; 20:1550-61. [DOI: 10.1089/ten.tea.2013.0207] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Simon Farnebo
- Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
- Section of Plastic Surgery, VA Palo Alto Health Care System, Palo Alto, California
| | - Colin Y.L. Woon
- Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
- Section of Plastic Surgery, VA Palo Alto Health Care System, Palo Alto, California
| | - Taliah Schmitt
- Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
- Section of Plastic Surgery, VA Palo Alto Health Care System, Palo Alto, California
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility, Stanford University Medical School, Stanford, California
| | - Maxwell Kim
- Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
- Section of Plastic Surgery, VA Palo Alto Health Care System, Palo Alto, California
| | - Hung Pham
- Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
- Section of Plastic Surgery, VA Palo Alto Health Care System, Palo Alto, California
| | - James Chang
- Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Palo Alto, California
- Section of Plastic Surgery, VA Palo Alto Health Care System, Palo Alto, California
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26
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Ronaghi M, Nasr M, Ealy M, Durruthy-Durruthy R, Waldhaus J, Diaz GH, Joubert LM, Oshima K, Heller S. Inner ear hair cell-like cells from human embryonic stem cells. Stem Cells Dev 2014; 23:1275-84. [PMID: 24512547 DOI: 10.1089/scd.2014.0033] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In mammals, the permanence of many forms of hearing loss is the result of the inner ear's inability to replace lost sensory hair cells. Here, we apply a differentiation strategy to guide human embryonic stem cells (hESCs) into cells of the otic lineage using chemically defined attached-substrate conditions. The generation of human otic progenitor cells was dependent on fibroblast growth factor (FGF) signaling, and protracted culture led to the upregulation of markers indicative of differentiated inner ear sensory epithelia. Using a transgenic ESC reporter line based on a murine Atoh1 enhancer, we show that differentiated hair cell-like cells express multiple hair cell markers simultaneously. Hair cell-like cells displayed protrusions reminiscent of stereociliary bundles, but failed to fully mature into cells with typical hair cell cytoarchitecture. We conclude that optimized defined conditions can be used in vitro to attain otic progenitor specification and sensory cell differentiation.
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Affiliation(s)
- Mohammad Ronaghi
- 1 Department of Otolaryngology-Head & Neck Surgery, Stanford University School of Medicine , Stanford, California
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27
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Jiang X, Malkovskiy AV, Tian W, Sung YK, Sun W, Hsu JL, Manickam S, Wagh D, Joubert LM, Semenza GL, Rajadas J, Nicolls MR. Promotion of airway anastomotic microvascular regeneration and alleviation of airway ischemia by deferoxamine nanoparticles. Biomaterials 2013; 35:803-813. [PMID: 24161166 DOI: 10.1016/j.biomaterials.2013.09.092] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 09/24/2013] [Indexed: 01/25/2023]
Abstract
Airway tissue ischemia and hypoxia in human lung transplantation is a consequence of the sacrifice of the bronchial circulation during the surgical procedure and is a major risk factor for the development of airway anastomotic complications. Augmented expression of hypoxia-inducible factor (HIF)-1α promotes microvascular repair and alleviates allograft ischemia and hypoxia. Deferoxamine mesylate (DFO) is an FDA-approved iron chelator which has been shown to upregulate cellular HIF-1α. Here, we developed a nanoparticle formulation of DFO that can be topically applied to airway transplants at the time of surgery. In a mouse orthotopic tracheal transplant (OTT) model, the DFO nanoparticle was highly effective in enhancing airway microvascular perfusion following transplantation through the production of the angiogenic factors, placental growth factor (PLGF) and stromal cell-derived factor (SDF)-1. The endothelial cells in DFO treated airways displayed higher levels of p-eNOS and Ki67, less apoptosis, and decreased production of perivascular reactive oxygen species (ROS) compared to vehicle-treated airways. In summary, a DFO formulation topically-applied at the time of surgery successfully augmented airway anastomotic microvascular regeneration and the repair of alloimmune-injured microvasculature. This approach may be an effective topical transplant-conditioning therapy for preventing airway complications following clinical lung transplantation.
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Affiliation(s)
- Xinguo Jiang
- Division of Pulmonary/Critical Care, Department of Medicine, VA Palo Alto Health Care System/Stanford University School of Medicine, Stanford, CA, USA
| | | | - Wen Tian
- Division of Pulmonary/Critical Care, Department of Medicine, VA Palo Alto Health Care System/Stanford University School of Medicine, Stanford, CA, USA
| | - Yon K Sung
- Division of Pulmonary/Critical Care, Department of Medicine, VA Palo Alto Health Care System/Stanford University School of Medicine, Stanford, CA, USA
| | - Wenchao Sun
- Stanford BioADD Laboratory, Stanford, CA, USA
| | - Joe L Hsu
- Division of Pulmonary/Critical Care, Department of Medicine, VA Palo Alto Health Care System/Stanford University School of Medicine, Stanford, CA, USA
| | | | | | | | - Gregg L Semenza
- Vascular Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.,Departments of Pediatrics, Medicine, Oncology, Radiation Oncology, and Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.,McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Mark R Nicolls
- Division of Pulmonary/Critical Care, Department of Medicine, VA Palo Alto Health Care System/Stanford University School of Medicine, Stanford, CA, USA
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Gaume RM, Joubert LM. Airtight container for the transfer of atmosphere-sensitive materials into vacuum-operated characterization instruments. Rev Sci Instrum 2011; 82:123705. [PMID: 22225222 DOI: 10.1063/1.3669784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This paper describes the design and operation of a simple airtight container devised to facilitate the transfer of atmosphere-sensitive samples from a glovebox to the vacuum chamber of an analytical instrument such as a scanning electron microscope. The use of this device for characterizing the microstructure of highly hygroscopic strontium iodide ceramics by scanning electron microscopy is illustrated as an application example.
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Affiliation(s)
- Romain M Gaume
- CREOL, the College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816-2700, USA.
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Peng K, Broz P, Jones J, Joubert LM, Monack D. Elevated AIM2-mediated pyroptosis triggered by hypercytotoxic Francisella mutant strains is attributed to increased intracellular bacteriolysis. Cell Microbiol 2011; 13:1586-600. [PMID: 21883803 DOI: 10.1111/j.1462-5822.2011.01643.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Intracellular bacterial pathogens Francisella novicida and the Live Vaccine Strain (LVS) are recognized in the macrophage cytosol by the AIM2 inflammasome, which leads to the activation of caspase-1 and the processing and secretion of active IL-1β, IL-18 and pyroptosis. Previous studies have reported that F. novicida and LVS mutants in specific genes (e.g. FTT0584, mviN and ripA) induce elevated inflammasome activation and hypercytotoxicity in host cells, leading to the proposal that F. novicida and LVS may have proteins that actively modulate inflammasome activation. However, there has been no direct evidence of such inflammasome evasion mechanisms. Here, we demonstrate for the first time that the above mutants, along with a wide range of F. novicida hypercytotoxic mutants that are deficient for membrane-associated proteins (ΔFTT0584, ΔmviN, ΔripA, ΔfopA and ΔFTN1217) or deficient for genes involved in O-antigen or LPS biosynthesis (ΔwbtA and ΔlpxH) lyse more intracellularly, thus activating increased levels of AIM2-dependent pyroptosis and other innate immune signalling pathways. This suggests that an inflammasome-specific evasion mechanism may not be present in F. novicida and LVS. Furthermore, future studies may need to consider increased bacterial lysis as a possible cause of elevated stimulation of multiple innate immune pathways when the protein composition or surface carbohydrates of the bacterial membrane is altered.
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Affiliation(s)
- Kaitian Peng
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
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Neofytou EA, Chang E, Patlola B, Joubert LM, Rajadas J, Gambhir SS, Cheng Z, Robbins RC, Beygui RE. Adipose tissue-derived stem cells display a proangiogenic phenotype on 3D scaffolds. J Biomed Mater Res A 2011; 98:383-93. [PMID: 21630430 DOI: 10.1002/jbm.a.33113] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 02/22/2011] [Accepted: 03/09/2011] [Indexed: 01/24/2023]
Abstract
Ischemic heart disease is the leading cause of death worldwide. Recent studies suggest that adipose tissue-derived stem cells (ASCs) can be used as a potential source for cardiovascular tissue engineering due to their ability to differentiate along the cardiovascular lineage and to adopt a proangiogenic phenotype. To understand better ASCs' biology, we used a novel 3D culture device. ASCs' and b.END-3 endothelial cell proliferation, migration, and vessel morphogenesis were significantly enhanced compared to 2D culturing techniques. ASCs were isolated from inguinal fat pads of 6-week-old GFP+/BLI+ mice. Early passage ASCs cells (P3-P4), PKH26-labeled murine b.END-3 cells or a co-culture of ASCs and b.END-3 cells were seeded at a density of 1 × 10(5) on three different surface configurations: (a) a 2D surface of tissue culture plastic, (b) Matrigel, and (c) a highly porous 3D scaffold fabricated from inert polystyrene. VEGF expression, cell proliferation, and tubulization, were assessed using optical microscopy, fluorescence microscopy, 3D confocal microscopy, and SEM imaging (n = 6). Increased VEGF levels were seen in conditioned media harvested from co-cultures of ASCs and b.END-3 on either Matrigel or a 3D matrix. Fluorescence, confocal, SEM, bioluminescence revealed improved cell, proliferation, and tubule formation for cells seeded on the 3D polystyrene matrix. Collectively, these data demonstrate that co-culturing ASCs with endothelial cells in a 3D matrix environment enable us to generate prevascularized tissue-engineered constructs. This can potentially help us to surpass the tissue thickness limitations faced by the tissue engineering community today.
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Affiliation(s)
- Evgenios A Neofytou
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, California, USA
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Weimer PJ, Price NPJ, Kroukamp O, Joubert LM, Wolfaardt GM, Van Zyl WH. Studies of the extracellular glycocalyx of the anaerobic cellulolytic bacterium Ruminococcus albus 7. Appl Environ Microbiol 2006; 72:7559-66. [PMID: 17028224 PMCID: PMC1694240 DOI: 10.1128/aem.01632-06] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Anaerobic cellulolytic bacteria are thought to adhere to cellulose via several mechanisms, including production of a glycocalyx containing extracellular polymeric substances (EPS). As the compositions and structures of these glycocalyces have not been elucidated, variable-pressure scanning electron microscopy (VP-SEM) and chemical analysis were used to characterize the glycocalyx of the ruminal bacterium Ruminococcus albus strain 7. VP-SEM revealed that growth of this strain was accompanied by the formation of thin cellular extensions that allowed the bacterium to adhere to cellulose, followed by formation of a ramifying network that interconnected individual cells to one another and to the unraveling cellulose microfibrils. Extraction of 48-h-old whole-culture pellets (bacterial cells plus glycocalyx [G] plus residual cellulose [C]) with 0.1 N NaOH released carbohydrate and protein in a ratio of 1:5. Boiling of the cellulose fermentation residue in a neutral detergent solution removed almost all of the adherent cells and protein while retaining a residual network of adhering noncellular material. Trifluoroacetic acid hydrolysis of this residue (G plus C) released primarily glucose, along with substantial amounts of xylose and mannose, but only traces of galactose, the most abundant sugar in most characterized bacterial exopolysaccharides. Linkage analysis and characterization by nuclear magnetic resonance suggested that most of the glucosyl units were not present as partially degraded cellulose. Calculations suggested that the energy demand for synthesis of the nonprotein fraction of EPS by this organism represents only a small fraction (<4%) of the anabolic ATP expenditure of the bacterium.
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Affiliation(s)
- Paul J Weimer
- U.S. Dairy Forage Research Center, Agricultural Research Service, U.S. Department of Agriculture, Madison, WI 53706, USA.
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Abstract
BACKGROUND Adult elite competitive rock climbers are small in stature with low body mass and very low body fat percentage. These characteristics have generated concern that young climbers may attempt body mass reduction to extreme levels with adverse consequences for health and performance. No published anthropometry data for young competitive climbers exist. OBJECTIVE To describe the general anthropometric characteristics of junior US competitive rock climbers. METHODS Ninety subjects (mean (SD) age 13.5 (3.0) years) volunteered to participate. All competed at the Junior Competition Climbers Association US National Championship. Anthropometric variables, including height, mass, body mass index (BMI), arm span, biiliocristal and biacromial breadths, skinfold thickness at nine anatomical sites, forearm and hand volumes, and handgrip strength, were measured. Selected variables were expressed as ratio values and as normative age and sex matched centile scores where appropriate. A control group (n=45) of non-climbing children and youths who participated in a variety of sports activities, including basketball, cross country running, cross country skiing, soccer, and swimming, underwent the same testing procedures in the Exercise Science Laboratory of Northern Michigan University. RESULTS Mean (SD) self reported climbing ability was 11.80 (1.20), or about 5.11 d on the Yosemite decimal system scale. The mean (SD) experience level was 3.2 (1.9) years, and subjects competed in 10 (5) organised competitions over a 12 month period. Despite similarity in age, there were significant differences (p<0.01) between climbers and control subjects for height, mass, centile scores for height and mass, ratio of arm span to height ("ape index"), biiliocristal/biacromial ratio, sum of seven and sum of nine skinfolds, estimated body fat percentage, and handgrip/mass ratio. Despite significantly lower skinfold sums and estimated body fat percentage, no differences were found between climbers and controls for absolute BMI or BMI expressed as a centile score. CONCLUSIONS Young competitive climbers have similar general anthropometric characteristics to elite adult climbers. These include relatively small stature, low body mass, low sums of skinfolds, and high handgrip to mass ratio. Relative to age matched athletic non-climbers, climbers appear to be more linear in body type with narrow shoulders relative to hips. Differences in body composition exist between climbers and non-climbing athletes despite similar BMI values.
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Affiliation(s)
- P B Watts
- Northern Michigan University, Marquette, MI 49855, USA.
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Joubert LM, Valette LR. [Behavior of Brucella abortus in phagocytes. The immunophagocytic test of the activity of anti-brucellar vaccines and their immunostimulants]. Bull Acad Vet Fr 1967; 40:111-24. [PMID: 4985093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Joubert LM, Valette LR. [Immuno-stimulating properties of a mixture of paraffin hydrocarbons and polyhydroxyethylenic oleic glycerides]. Bull Acad Vet Fr 1967; 40:99-110. [PMID: 5622728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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