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Bender RHF, O’Donnell BT, Shergill B, Pham BQ, Tahmouresie S, Sanchez CN, Juat DJ, Hatch MMS, Shirure VS, Wortham M, Nguyen-Ngoc KV, Jun Y, Gaetani R, Christman KL, Teyton L, George SC, Sander M, Hughes CCW. A vascularized 3D model of the human pancreatic islet for ex vivostudy of immune cell-islet interaction. Biofabrication 2024; 16:025001. [PMID: 38128127 PMCID: PMC10782895 DOI: 10.1088/1758-5090/ad17d0] [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: 08/16/2023] [Revised: 11/24/2023] [Accepted: 12/21/2023] [Indexed: 12/23/2023]
Abstract
Insulin is an essential regulator of blood glucose homeostasis that is produced exclusively byβcells within the pancreatic islets of healthy individuals. In those affected by diabetes, immune inflammation, damage, and destruction of isletβcells leads to insulin deficiency and hyperglycemia. Current efforts to understand the mechanisms underlyingβcell damage in diabetes rely onin vitro-cultured cadaveric islets. However, isolation of these islets involves removal of crucial matrix and vasculature that supports islets in the intact pancreas. Unsurprisingly, these islets demonstrate reduced functionality over time in standard culture conditions, thereby limiting their value for understanding native islet biology. Leveraging a novel, vascularized micro-organ (VMO) approach, we have recapitulated elements of the native pancreas by incorporating isolated human islets within a three-dimensional matrix nourished by living, perfusable blood vessels. Importantly, these islets show long-term viability and maintain robust glucose-stimulated insulin responses. Furthermore, vessel-mediated delivery of immune cells to these tissues provides a model to assess islet-immune cell interactions and subsequent islet killing-key steps in type 1 diabetes pathogenesis. Together, these results establish the islet-VMO as a novel,ex vivoplatform for studying human islet biology in both health and disease.
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Affiliation(s)
- R Hugh F Bender
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, United States of America
| | - Benjamen T O’Donnell
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, United States of America
| | - Bhupinder Shergill
- Department of Biomedical Engineering, University of California, Davis, CA, United States of America
| | - Brittany Q Pham
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, United States of America
| | - Sima Tahmouresie
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, United States of America
| | - Celeste N Sanchez
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, United States of America
| | - Damie J Juat
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, United States of America
| | - Michaela M S Hatch
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, United States of America
| | - Venktesh S Shirure
- Department of Biomedical Engineering, University of California, Davis, CA, United States of America
| | - Matthew Wortham
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, CA, United States of America
| | - Kim-Vy Nguyen-Ngoc
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, CA, United States of America
| | - Yesl Jun
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, CA, United States of America
| | - Roberto Gaetani
- Department of Bioengineering, University of California, San Diego, CA, United States of America
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Karen L Christman
- Department of Cellular & Molecular Medicine, University of California, San Diego, CA, United States of America
- Department of Bioengineering, University of California, San Diego, CA, United States of America
| | - Luc Teyton
- Department of Immunology & Microbiology, The Scripps Research Institute, San Diego, CA, United States of America
| | - Steven C George
- Department of Biomedical Engineering, University of California, Davis, CA, United States of America
| | - Maike Sander
- Pediatric Diabetes Research Center, Department of Pediatrics, University of California, San Diego, CA, United States of America
- Department of Cellular & Molecular Medicine, University of California, San Diego, CA, United States of America
| | - Christopher C W Hughes
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, United States of America
- Department of Biomedical Engineering, University of California, Irvine, CA, United States of America
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2
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Biendarra‐Tiegs SM, Yechikov S, Shergill B, Brumback B, Takahashi K, Shirure VS, Gonzalez RE, Houshmand L, Zhong D, Weng K, Silva J, Smith TW, Rentschler SL, George SC. An iPS-derived in vitro model of human atrial conduction. Physiol Rep 2022; 10:e15407. [PMID: 36117385 PMCID: PMC9483613 DOI: 10.14814/phy2.15407] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 04/27/2022] [Accepted: 07/14/2022] [Indexed: 11/25/2022] Open
Abstract
Atrial fibrillation (AF) is the most common arrhythmia in the United States, affecting approximately 1 in 10 adults, and its prevalence is expected to rise as the population ages. Treatment options for AF are limited; moreover, the development of new treatments is hindered by limited (1) knowledge regarding human atrial electrophysiological endpoints (e.g., conduction velocity [CV]) and (2) accurate experimental models. Here, we measured the CV and refractory period, and subsequently calculated the conduction wavelength, in vivo (four subjects with AF and four controls), and ex vivo (atrial slices from human hearts). Then, we created an in vitro model of human atrial conduction using induced pluripotent stem (iPS) cells. This model consisted of iPS-derived human atrial cardiomyocytes plated onto a micropatterned linear 1D spiral design of Matrigel. The CV (34-41 cm/s) of the in vitro model was nearly five times faster than 2D controls (7-9 cm/s) and similar to in vivo (40-64 cm/s) and ex vivo (28-51 cm/s) measurements. Our iPS-derived in vitro model recapitulates key features of in vivo atrial conduction and may be a useful methodology to enhance our understanding of AF and model patient-specific disease.
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Affiliation(s)
| | - Sergey Yechikov
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Bhupinder Shergill
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Brittany Brumback
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Kentaro Takahashi
- Department of MedicineWashington University in St. LouisSt. LouisMissouriUSA
| | - Venktesh S. Shirure
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Ruth Estelle Gonzalez
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Laura Houshmand
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Denise Zhong
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
| | - Kuo‐Chan Weng
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Jon Silva
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMissouriUSA
| | - Timothy W. Smith
- Department of MedicineWashington University in St. LouisSt. LouisMissouriUSA
| | - Stacey L. Rentschler
- Department of MedicineWashington University in St. LouisSt. LouisMissouriUSA
- Department of Developmental BiologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Steven C. George
- Department of Biomedical EngineeringUniversity of California, DavisDavisCaliforniaUSA
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3
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Shirure VS, Lam SF, Shergill B, Chu YE, Ng NR, George SC. Quantitative design strategies for fine control of oxygen in microfluidic systems. Lab Chip 2020; 20:3036-3050. [PMID: 32716448 DOI: 10.1039/d0lc00350f] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Hypoxia, or low oxygen (O2) tension, is a central feature of important disease processes including wound healing and cancer. Subtle temporal and spatial variations (≤1% change) in the concentration of O2 can profoundly impact gene expression and cellular functions. Sodium sulfite reacts rapidly with O2 and can be used to lower the O2 concentrations in PDMS-based tissue culture systems without exposing the cell culture to the chemical reaction. By carefully considering the mass transfer and reaction kinetics of sodium sulfite and O2, we developed a flexible theoretical framework to design an experimental microfluidic system that provides fine spatial and temporal control of O2 tension. The framework packages the dimensions, fluid flow, reaction rates, concentrations, and material properties of the fluidic lines and device into dimensionless groups that facilitate scaling and design. We validated the theoretical results by experimentally measuring O2 tension throughout the experimental system using phosphorescence lifetime imaging. We then tested the system by examining the impact of hypoxia inducible factor-1α (HIF-1α) on the proliferation and migration of MDA-MB-231 breast cancer cells. Using this system, we demonstrate that mild constant hypoxia (≤4%) induces HIF-1α mediated functional changes in the tumor cells. Furthermore, slow (>12 hours), but not rapid (<1 hour), fluctuations in O2 tension impact HIF-1α mediated proliferation and migration. Our results provide a generalized framework for fine temporal and spatial control of O2 and emphasize the need to consider mild spatial and temporal changes in O2 tension as potentially important factors in disease processes such as cancer.
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Affiliation(s)
- Venktesh S Shirure
- Department of Biomedical Engineering, University of California Davis, CA, USA.
| | - Sandra F Lam
- Department of Biomedical Engineering, Washington University in St. Louis, MO, USA
| | - Bhupinder Shergill
- Department of Biomedical Engineering, University of California Davis, CA, USA.
| | - Yunli E Chu
- Department of Biomedical Engineering, Washington University in St. Louis, MO, USA
| | - Natalie R Ng
- Department of Biomedical Engineering, Washington University in St. Louis, MO, USA
| | - Steven C George
- Department of Biomedical Engineering, University of California Davis, CA, USA.
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4
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Abstract
Following on from Part 1 of the series (regional nerve blocks for the face and scalp), we guide the clinician through the anatomy and cutaneous innervation of the digits, wrist and ankle, providing a practical step-by-step guide to regional nerve blockade of these areas.
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Affiliation(s)
- T Davies
- Department of Anaesthesia, Royal Free London NHS Foundation Trust, UK
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5
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Abstract
The aim of this two-part series is to provide an up-to-date review of essential regional nerve blocks for dermatological practice. In Part 1, we give a concise overview of local anaesthetics and their potential complications, as well as the relevant anatomy and cutaneous innervation of the face and scalp. This culminates in a step-by-step practical guide to performing each nerve block.
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Affiliation(s)
- T Davies
- Department of Anaesthesia, Royal Free London NHS Foundation Trust, UK
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6
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Meloty-Kapella L, Shergill B, Kuon J, Botvinick E, Weinmaster G. Notch ligand endocytosis generates mechanical pulling force dependent on dynamin, epsins, and actin. Dev Cell 2012; 22:1299-312. [PMID: 22658936 DOI: 10.1016/j.devcel.2012.04.005] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 02/15/2012] [Accepted: 04/04/2012] [Indexed: 12/17/2022]
Abstract
Notch signaling induced by cell surface ligands is critical to development and maintenance of many eukaryotic organisms. Notch and its ligands are integral membrane proteins that facilitate direct cell-cell interactions to activate Notch proteolysis and release the intracellular domain that directs Notch-specific cellular responses. Genetic studies suggest that Notch ligands require endocytosis, ubiquitylation, and epsin endocytic adaptors to activate signaling, but the exact role of ligand endocytosis remains unresolved. Here we characterize a molecularly distinct mode of clathrin-mediated endocytosis requiring ligand ubiquitylation, epsins, and actin for ligand cells to activate signaling in Notch cells. Using a cell-bead optical tweezers system, we obtained evidence for cell-mediated mechanical force dependent on this distinct mode of ligand endocytosis. We propose that the mechanical pulling force produced by endocytosis of Notch-bound ligand drives conformational changes in Notch that permit activating proteolysis.
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Affiliation(s)
- Laurence Meloty-Kapella
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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7
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Shergill B, Meloty-Kapella L, Musse AA, Weinmaster G, Botvinick E. Optical tweezers studies on Notch: single-molecule interaction strength is independent of ligand endocytosis. Dev Cell 2012; 22:1313-20. [PMID: 22658935 DOI: 10.1016/j.devcel.2012.04.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 02/15/2012] [Accepted: 04/11/2012] [Indexed: 10/28/2022]
Abstract
Notch signaling controls diverse cellular processes critical to development and disease. Cell surface ligands bind Notch on neighboring cells but require endocytosis to activate signaling. The role ligand endocytosis plays in Notch activation has not been established. Here we integrate optical tweezers with cell biological and biochemical methods to test the prevailing model that ligand endocytosis facilitates recycling to enhance ligand interactions with Notch necessary to trigger signaling. Specifically, single-molecule measurements indicate that interference of ligand endocytosis and/or recycling does not alter the force required to rupture bonds formed between cells expressing the Notch ligand Delta-like1 (Dll1) and laser-trapped Notch1 beads. Together, our analyses eliminate roles for ligand endocytosis and recycling in Dll1-Notch1 interactions and indicate that recycling indirectly affects signaling by regulating the accumulation of cell surface ligand. Importantly, our study demonstrates the utility of optical tweezers to test a role for ligand endocytosis in generating cell-mediated mechanical force.
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8
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Anderson SM, Shergill B, Barry ZT, Manousiouthakis E, Chen TT, Botvinick E, Platt MO, Iruela-Arispe ML, Segura T. VEGF internalization is not required for VEGFR-2 phosphorylation in bioengineered surfaces with covalently linked VEGF. Integr Biol (Camb) 2011; 3:887-96. [PMID: 21826315 DOI: 10.1039/c1ib00037c] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Vascular endothelial growth factor (VEGF) is known to activate proliferation, migration, and survival pathways in endothelial cells through phosphorylation of VEGF receptor-2 (VEGFR-2). VEGF has been incorporated into biomaterials through encapsulation, electrostatic sequestration, and covalent attachment, but the effect of these immobilization strategies on VEGF signaling has not been thoroughly investigated. Further, although growth factor internalization along with the receptor generally occurs in a physiological setting, whether this internalization is needed for receptor phosphorylation is not entirely clear. Here we show that VEGF covalently bound through a modified heparin molecule elicits an extended response of pVEGFR-2 in human umbilical vein endothelial cells (HUVECs) and that the covalent linkage reduces internalization of the growth factor during receptor endocytosis. Optical tweezer measurements show that the rupture force required to disrupt the heparin-VEGF-VEGFR-2 interaction increases from 3-8 pN to 6-12 pN when a covalent bond is introduced between VEGF and heparin. Importantly, by covalently binding VEGF to a heparin substrate, the stability (half-life) of VEGF is extended over three-fold. Here, mathematical models support the biological conclusions, further suggesting that VEGF internalization is significantly reduced when covalently bound, and indicating that VEGF is available for repeated phosphorylation events.
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Affiliation(s)
- Sean M Anderson
- Department of Chemical and Biomolecular Engineering, University of California, 420 Westwood Plaza, 5531 Boelter Hall, Los Angeles, CA 90095, USA
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9
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Abstract
Facial hyperpigmented disorders are a common complaint in the adult population of all races. First-line topical treatments are usually hydroquinone or topical retinoids, which can cause irritant reactions. The need for better tolerated, yet effective, skin lightening agents that could be utilized by a wider population has led to the investigation of several potential botanical/natural compounds. There are currently many topical cosmetic formulations claiming skin depigmenting effects. A few of the ingredients (e.g. soy) are supported not only by in vitro results but also by a body of controlled clinical efficacy studies; other ingredients, instead, are backed mostly by in vitro data and a few small uncontrolled clinical studies. In this review, we describe the most common natural ingredients used for skin depigmentation and their major published studies: soy, licorice extracts, kojic acid, arbutin, niacinamide, N-acetylglucosamine, COFFEEBERRY(™) and green tea.
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Affiliation(s)
- J J Leyden
- University of Pennsylvania, Philadelphia, PA, USA
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10
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Affiliation(s)
- A L Ekeowa-Anderson
- Department of Dermatology, The Royal London Hospital, Whitechapel, London E1 1BB, UK.
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11
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Abstract
Scleromyxoedema is a rare skin disease, characterized by deposition of acid mucopolysaccharides in the dermis. Although the disease primarily affects the skin, cardiovascular, renal and rheumatological manifestations have been described. In addition to these noncutaneous manifestations, about 15% of patients have central neurological symptoms such as psychosis, convulsions and encephalopathy. Successful therapy is difficult but high-dose intravenous immunoglobulin (IVIg) has been reported to be a successful treatment. We describe a patient with scleromyxoedema who presented with novel central nervous system manifestations of chronic cognitive impairment and dementia (Folstein Mini Mental State test score 8/30), which improved within a week after treatment with high-dose IVIg, with full restoration (Folstein Mini Mental State test score 27/30) at 2 months.
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Affiliation(s)
- B Shergill
- Department of Dermatology, The Royal Free Hospital, London NW3 2QG, UK.
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12
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13
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Cason J, Kaye JN, Jewers RJ, Kambo PK, Bible JM, Kell B, Shergill B, Pakarian F, Raju KS, Best JM. Perinatal infection and persistence of human papillomavirus types 16 and 18 in infants. J Med Virol 1995; 47:209-18. [PMID: 8551271 DOI: 10.1002/jmv.1890470305] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Perinatal transmission of genital human papillomaviruses (HPVs), including HPV-16 and -18 which are associated with anogenital carcinomas have been described previously [Pakarian et al. (1994): British Journal of Obstetrics and Gynaecology 101:514-517; Kaye et al. (1994) Journal of Medical Virology 44:415-421]. A study was undertaken to investigate whether HPV-16 and -18 DNA in infants contaminated at delivery persists until they are 6 months of age. Of 61 pregnant women recruited, 42 (68.8%) were HPV-16 and 13 (21.3%) were HPV-18 DNA positive. At 24 hr there were transmission rates from HPV DNA positive mothers to their infants of about 73% (HPV-16: 69%; HPV-18: 76.9%). Ten mothers who were both HPV-16 and -18 DNA positive produced six (60%) infants who were also doubly positive at 24 hr. HPV DNA persisted to 6 weeks in 79.5% (HPV-16: 84%; HPV-18: 75%) of those infants who were positive at birth. At 6 months of age, persistent HPV-16 DNA was detected in 83.3% of cases, but HPV-18 DNA persistence at this time was 20%. To extend these observations over a greater age range of children HPV-16 L1 and L2 proteins were expressed in insect cells via recombinant baculoviruses and sera from 229 children were examined to determine at what age IgM antibodies to HPV were acquired. There was a bimodal distribution of IgM seropositivity which peaked between 2 and 5 and 13 and 16 years of age, suggesting that two distinct modes of transmission may occur. The observation that infection with high cancer risk genital HPVs may occur in early life and persist is of considerable importance for HPV vaccine strategies.
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Affiliation(s)
- J Cason
- Richard Dimbleby Laboratory of Cancer Virology, Department of Virology, Rayne Institute, London, United Kingdom
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