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Kohl PA, Song C, Fletcher BJ, Best RL, Tchounwou C, Garcia Arceo X, Chung PJ, Miller HP, Wilson L, Choi MC, Li Y, Feinstein SC, Safinya CR. Complexes of tubulin oligomers and tau form a viscoelastic intervening network cross-bridging microtubules into bundles. Nat Commun 2024; 15:2362. [PMID: 38491006 PMCID: PMC10943092 DOI: 10.1038/s41467-024-46438-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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 02/28/2024] [Indexed: 03/18/2024] Open
Abstract
The axon-initial-segment (AIS) of mature neurons contains microtubule (MT) fascicles (linear bundles) implicated as retrograde diffusion barriers in the retention of MT-associated protein (MAP) tau inside axons. Tau dysfunction and leakage outside of the axon is associated with neurodegeneration. We report on the structure of steady-state MT bundles in varying concentrations of Mg2+ or Ca2+ divalent cations in mixtures containing αβ-tubulin, full-length tau, and GTP at 37 °C in a physiological buffer. A concentration-time kinetic phase diagram generated by synchrotron SAXS reveals a wide-spacing MT bundle phase (Bws), a transient intermediate MT bundle phase (Bint), and a tubulin ring phase. SAXS with TEM of plastic-embedded samples provides evidence of a viscoelastic intervening network (IN) of complexes of tubulin oligomers and tau stabilizing MT bundles. In this model, αβ-tubulin oligomers in the IN are crosslinked by tau's MT binding repeats, which also link αβ-tubulin oligomers to αβ-tubulin within the MT lattice. The model challenges whether the cross-bridging of MTs is attributed entirely to MAPs. Tubulin-tau complexes in the IN or bound to isolated MTs are potential sites for enzymatic modification of tau, promoting nucleation and growth of tau fibrils in tauopathies.
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Affiliation(s)
- Phillip A Kohl
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Chaeyeon Song
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Amorepacific R&I Center, Yongin, 17074, Republic of Korea
| | - Bretton J Fletcher
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Rebecca L Best
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Serimmune Inc., 150 Castilian Dr., Goleta, CA, 93117, USA
| | - Christine Tchounwou
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Ximena Garcia Arceo
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Chemistry and Biochemistry, University of California, San Diego, San Diego, CA, 93106, USA
| | - Peter J Chung
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, 90089, USA
| | - Herbert P Miller
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Leslie Wilson
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Myung Chul Choi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Daejeon, 34141, Korea
| | - Youli Li
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
| | - Stuart C Feinstein
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Cyrus R Safinya
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
- Biomolecular Science and Engineering, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA.
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
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Fisher WS, Tchounwou C, Wei S, Roberts L, Ewert KK, Safinya CR. Exosomes are secreted at similar densities by M21 and PC3 human cancer cells and show paclitaxel solubility. Biochim Biophys Acta Biomembr 2022; 1864:183841. [PMID: 34953781 PMCID: PMC8896395 DOI: 10.1016/j.bbamem.2021.183841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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] [Received: 04/17/2021] [Revised: 12/08/2021] [Accepted: 12/11/2021] [Indexed: 06/14/2023]
Abstract
Exosomes are cell-secreted vesicles less than ≈150 nm in size that contain gene-encoding and gene-silencing RNA and cytosolic proteins with roles in intercellular communication. Interest in the use of exosomes as targeted drug delivery vehicles has grown since it was shown that they can bind specific cells and deliver intact genetic material to the cytosol of target cells. We isolated extracellular vesicles (EVs), consisting of a mixture of exosomes and microvesicles, from prostate (PC3) and melanoma (M21) cancer cell lines using serial ultracentrifugation. Interrogation via western blot analysis confirmed enrichment of CD63, a widely recognized EV surface protein, in the EV pellet from both cell lines. Nanoparticle tracking analysis (NTA) of EV pellets revealed that the two cell lines produced distinct vesicle size profiles in the ≈30 nm to ≈400 nm range. NTA further showed that the fraction of exosomes to all EVs was constant, suggesting cellular mechanisms that control the fraction of secreted vesicles that are exosomes. Transmission electron microscopy (TEM) images of the unmodified PC3 EVs showed vesicles with cup-like (i.e., nanocapsule) and previously unreported prolate morphologies. The observed non-spherical morphologies for dehydrated exosomal vesicles (size ≈30-100 nm) are most likely related to the dense packing of proteins in exosome membranes. Solubility phase diagram data showed that EVs enhanced the solubility of paclitaxel (PTX) in aqueous solution compared to a water-only control. Combined with their inherent targeting and cytosol delivery properties, these findings highlight the potential advantages of using exosomes as chemotherapeutic drug carriers in vivo.
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Affiliation(s)
- William S Fisher
- Materials Department, Molecular, Cellular, and Developmental Biology Department, Physics Department, and Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106, USA
| | - Christine Tchounwou
- Materials Department, Molecular, Cellular, and Developmental Biology Department, Physics Department, and Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106, USA
| | - Sophia Wei
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106, USA
| | - Logan Roberts
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106, USA
| | - Kai K Ewert
- Materials Department, Molecular, Cellular, and Developmental Biology Department, Physics Department, and Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106, USA
| | - Cyrus R Safinya
- Materials Department, Molecular, Cellular, and Developmental Biology Department, Physics Department, and Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA 93106, USA.
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Tchounwou C, Sinha SS, Viraka Nellore BP, Pramanik A, Kanchanapally R, Jones S, Chavva SR, Ray PC. Hybrid Theranostic Platform for Second Near-IR Window Light Triggered Selective Two-Photon Imaging and Photothermal Killing of Targeted Melanoma Cells. ACS Appl Mater Interfaces 2015; 7:20649-56. [PMID: 26327304 PMCID: PMC4669052 DOI: 10.1021/acsami.5b05225] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [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: 05/04/2023]
Abstract
Despite advances in the medical field, even in the 21st century cancer is one of the leading causes of death for men and women in the world. Since the second near-infrared (NIR) biological window light between 950 and 1350 nm offers highly efficient tissue penetration, the current article reports the development of hybrid theranostic platform using anti-GD2 antibody attached gold nanoparticle (GNP) conjugated, single-wall carbon nanotube (SWCNT) for second near-IR light triggered selective imaging and efficient photothermal therapy of human melanoma cancer cell. Reported results demonstrate that due to strong plasmon-coupling, two-photon luminescence (TPL) intensity from theranostic GNP attached SWCNT materials is 6 orders of magnitude higher than GNP or SWCNT alone. Experimental and FDTD simulation data indicate that the huge enhancement of TPL intensity is mainly due to strong resonance enhancement coupled with the stronger electric field enhancement. Due to plasmon coupling, the theranostic material serves as a local nanoantennae to enhance the photothermal capability via strong optical energy absorption. Reported data show that theranostic SWCNT can be used for selective two-photon imaging of melanoma UACC903 cell using 1100 nm light. Photothermal killing experiment with 1.0 W/cm(2) 980 nm laser light demonstrates that 100% of melanoma UACC903 cells can be killed using theranostic SWCNT bind melanoma cells after just 8 min of exposure. These results demonstrate that due to plasmon coupling, the theranostic GNP attached SWCNT material serves as a two-photon imaging and photothermal source for cancer cells in biological window II.
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Affiliation(s)
- Christine Tchounwou
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Sudarson Sekhar Sinha
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Bhanu Priya Viraka Nellore
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Avijit Pramanik
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Rajashekhar Kanchanapally
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Stacy Jones
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Suhash Reddy Chavva
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Paresh Chandra Ray
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
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Shi Y, Pramanik A, Tchounwou C, Pedraza F, Crouch RA, Chavva SR, Vangara A, Sinha SS, Jones S, Sardar D, Hawker C, Ray PC. Multifunctional biocompatible graphene oxide quantum dots decorated magnetic nanoplatform for efficient capture and two-photon imaging of rare tumor cells. ACS Appl Mater Interfaces 2015; 7:10935-43. [PMID: 25939643 PMCID: PMC4570252 DOI: 10.1021/acsami.5b02199] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [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: 05/08/2023]
Abstract
Circulating tumor cells (CTCs) are extremely rare cells in blood containing billions of other cells. The selective capture and identification of rare cells with sufficient sensitivity is a real challenge. Driven by this need, this manuscript reports the development of a multifunctional biocompatible graphene oxide quantum dots (GOQDs) coated, high-luminescence magnetic nanoplatform for the selective separation and diagnosis of Glypican-3 (GPC3)-expressed Hep G2 liver cancer tumor CTCs from infected blood. Experimental data show that an anti-GPC3-antibody-attached multifunctional nanoplatform can be used for selective Hep G2 hepatocellular carcinoma tumor cell separation from infected blood containing 10 tumor cells/mL of blood in a 15 mL sample. Reported data indicate that, because of an extremely high two-photon absorption cross section (40530 GM), an anti-GPC3-antibody-attached GOQDs-coated magnetic nanoplatform can be used as a two-photon luminescence platform for selective and very bright imaging of a Hep G2 tumor cell in a biological transparency window using 960 nm light. Experimental results with nontargeted GPC3(-) and SK-BR-3 breast cancer cells show that multifunctional-nanoplatform-based cell separation, followed by two-photon imaging, is highly selective for Hep G2 hepatocellular carcinoma tumor cells.
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Affiliation(s)
- Yongliang Shi
- Department of Chemistry
and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Avijit Pramanik
- Department of Chemistry
and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Christine Tchounwou
- Department of Chemistry
and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Francisco Pedraza
- Department of Physics and Astronomy, University
of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Rebecca A. Crouch
- Department of Chemistry
and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Suhash Reddy Chavva
- Department of Chemistry
and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Aruna Vangara
- Department of Chemistry
and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Sudarson Sekhar Sinha
- Department of Chemistry
and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Stacy Jones
- Department of Chemistry
and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
| | - Dhiraj Sardar
- Department of Physics and Astronomy, University
of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Craig Hawker
- Department of Chemistry and Biochemistry and Materials Research Laboratory, Materials Department, University of California at Santa Barbara, Santa Barbara, California 93106, United States
| | - Paresh Chandra Ray
- Department of Chemistry
and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States
- E-mail:. Fax: +16019793674
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Kanchanapally R, Viraka Nellore BP, Sinha SS, Pedraza F, Jones SJ, Pramanik A, Chavva SR, Tchounwou C, Shi Y, Vangara A, Sardar D, Ray PC. Antimicrobial Peptide-Conjugated Graphene Oxide Membrane for Efficient Removal and Effective Killing of Multiple Drug Resistant Bacteria. RSC Adv 2015; 5:18881-18887. [PMID: 26294958 PMCID: PMC4539267 DOI: 10.1039/c5ra01321f] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
According to the World Health Organization (WHO), multiple drug-resistant (MDR) bacterial infection is a top threat to human health. Since bacteria evolve to resist antibiotics faster than scientists can develop new classes of drugs, the development of new materials which can be used, not only for separation, but also for effective disinfection of drug resistant pathogens is urgent. Driven by this need, we report for the first time the development of a nisin antimicrobial peptide conjugated, three dimensional (3D) porous graphene oxide membrane for identification, effective separation, and complete disinfection of MDR methicillin-resistant Staphylococcus aureus (MRSA) pathogens from water. Experimental data show that due to the size differences, MRSA is captured by the porous membrane, allowing only water to pass through. SEM, TEM, and fluorescence images confirm that pathogens are captured by the membrane. RT-PCR data with colony counting indicate that almost 100% of MRSA can be removed and destroyed from the water sample using the developed membrane. Comparison of MDR killing data between nisin alone, the graphene oxide membrane and the nisin attached graphene oxide membrane demonstrate that the nisin antimicrobial peptide attached graphene oxide membrane can dramatically enhance the possibility of destroying MRSA via a synergestic effect due to the multimodal mechanism.
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Affiliation(s)
| | | | | | - Francisco Pedraza
- Department of Physics and Astronomy, University of Texas at San Antonio, TX, USA
| | | | | | | | | | | | | | - Dhiraj Sardar
- Department of Physics and Astronomy, University of Texas at San Antonio, TX, USA
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