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Lee H, Wiegand DJ, Griswold K, Punthambaker S, Chun H, Kohman RE, Church GM. Photon-directed multiplexed enzymatic DNA synthesis for molecular digital data storage. Nat Commun 2020; 11:5246. [PMID: 33067441 PMCID: PMC7567835 DOI: 10.1038/s41467-020-18681-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 08/27/2020] [Indexed: 01/07/2023] Open
Abstract
New storage technologies are needed to keep up with the global demands of data generation. DNA is an ideal storage medium due to its stability, information density and ease-of-readout with advanced sequencing techniques. However, progress in writing DNA is stifled by the continued reliance on chemical synthesis methods. The enzymatic synthesis of DNA is a promising alternative, but thus far has not been well demonstrated in a parallelized manner. Here, we report a multiplexed enzymatic DNA synthesis method using maskless photolithography. Rapid uncaging of Co2+ ions by patterned UV light activates Terminal deoxynucleotidyl Transferase (TdT) for spatially-selective synthesis on an array surface. Spontaneous quenching of reactions by the diffusion of excess caging molecules confines synthesis to light patterns and controls the extension length. We show that our multiplexed synthesis method can be used to store digital data by encoding 12 unique DNA oligonucleotide sequences with video game music, which is equivalent to 84 trits or 110 bits of data.
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Affiliation(s)
- Howon Lee
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
- Wyss Institute for Biologically Inspired Engineering, Boston, MA, 02115, USA
| | - Daniel J Wiegand
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
- Wyss Institute for Biologically Inspired Engineering, Boston, MA, 02115, USA
| | - Kettner Griswold
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
- Wyss Institute for Biologically Inspired Engineering, Boston, MA, 02115, USA
- MIT Media Lab, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Charles Stark Draper Laboratory, Cambridge, MA, 02139, USA
| | - Sukanya Punthambaker
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
- Wyss Institute for Biologically Inspired Engineering, Boston, MA, 02115, USA
| | - Honggu Chun
- Department of Biomedical Engineering, Korea University, 466 Hana Science Hall, 145 Anamro, Seongbukgu, 02841, Seoul, South Korea
| | - Richie E Kohman
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA.
- Wyss Institute for Biologically Inspired Engineering, Boston, MA, 02115, USA.
| | - George M Church
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA.
- Wyss Institute for Biologically Inspired Engineering, Boston, MA, 02115, USA.
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2
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Sweeney D, Hollins F, Gomez E, Mistry R, Saunders R, Challiss RAJ, Brightling CE. No evidence for altered intracellular calcium-handling in airway smooth muscle cells from human subjects with asthma. BMC Pulm Med 2015; 15:12. [PMID: 25880173 PMCID: PMC4349477 DOI: 10.1186/s12890-015-0009-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 02/03/2015] [Indexed: 11/30/2022] Open
Abstract
Background Asthma is characterized by airway hyper-responsiveness and variable airflow obstruction, in part as a consequence of hyper-contractile airway smooth muscle, which persists in primary cell culture. One potential mechanism for this hyper-contractility is abnormal intracellular Ca2+ handling. Methods We sought to compare intracellular Ca2+ handling in airway smooth muscle cells from subjects with asthma compared to non-asthmatic controls by measuring: i) bradykinin-stimulated changes in inositol 1,4,5-trisphosphate (IP3) accumulation and intracellular Ca2+ concentration, ii) sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) expression, iii) mechanisms of cytoplasmic Ca2+ clearance assessed following instantaneous flash photolytic release of Ca2+ into the cytoplasm. Results We found no differences in airway smooth muscle cell basal intracellular Ca2+ concentrations, bradykinin-stimulated IP3 accumulation or intracellular Ca2+ responses. Quantification of SERCA2 mRNA or protein expression levels revealed no differences in ASM cells obtained from subjects with asthma compared to non-asthmatic controls. We did not identify differences in intracellular calcium kinetics assessed by flash photolysis and calcium uncaging independent of agonist-activation with or without SERCA inhibition. However, we did observe some correlations in subjects with asthma between lung function and the different cellular measurements of intracellular Ca2+ handling, with poorer lung function related to increased rate of recovery following flash photolytic elevation of cytoplasmic Ca2+ concentration. Conclusions Taken together, the experimental results reported in this study do not demonstrate major fundamental differences in Ca2+ handling between airway smooth muscle cells from non-asthmatic and asthmatic subjects. Therefore, increased contraction of airway smooth muscle cells derived from asthmatic subjects cannot be fully explained by altered Ca2+ homeostasis.
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Affiliation(s)
- David Sweeney
- Department of Infection, Immunity & Inflammation, and Institute for Lung Health, University of Leicester, Glenfield Hospital, Leicester, LE3 9QP, UK. .,Department of Cell Physiology & Pharmacology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester, LE1 9HN, UK.
| | - Fay Hollins
- Department of Infection, Immunity & Inflammation, and Institute for Lung Health, University of Leicester, Glenfield Hospital, Leicester, LE3 9QP, UK.
| | - Edith Gomez
- Department of Infection, Immunity & Inflammation, and Institute for Lung Health, University of Leicester, Glenfield Hospital, Leicester, LE3 9QP, UK. .,Department of Cell Physiology & Pharmacology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester, LE1 9HN, UK.
| | - Rajendra Mistry
- Department of Cell Physiology & Pharmacology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester, LE1 9HN, UK.
| | - Ruth Saunders
- Department of Infection, Immunity & Inflammation, and Institute for Lung Health, University of Leicester, Glenfield Hospital, Leicester, LE3 9QP, UK.
| | - Robert Alfred John Challiss
- Department of Cell Physiology & Pharmacology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester, LE1 9HN, UK.
| | - Christopher Edward Brightling
- Department of Infection, Immunity & Inflammation, and Institute for Lung Health, University of Leicester, Glenfield Hospital, Leicester, LE3 9QP, UK.
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3
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Zhang LX, Li HF, Wang LD, Jin S, Dou XC, Tian ZF, Ma Q. Resveratrol and genistein inhibition of rat isolated gastrointestinal contractions and related mechanisms. World J Gastroenterol 2014; 20:15335-15342. [PMID: 25386082 PMCID: PMC4223267 DOI: 10.3748/wjg.v20.i41.15335] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 07/22/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effects and underlying mechanisms of resveratrol and genistein on contractile responses of rat gastrointestinal smooth muscle.
METHODS: Isolated strips of gastrointestinal smooth muscle from Spraque-Dawley rats were suspended in organ baths containing Kreb’s solution, and the contractility of smooth muscles was measured before and after incubation with resveratrol and genistein, and the related mechanisms were studied by co-incubation with various inhibitors.
RESULTS: Resveratrol and genistein dose-dependently decreased the resting tension, and also reduced the mean contractile amplitude of gastrointestinal smooth muscle. Estrogen receptor blockades (ICI 182780 and tamoxifen) failed to alter the inhibitory effects induced by resveratrol and genistein. However, their effects were attenuated by inhibitions of α-adrenergic receptor (phentolamine), nitric oxide synthase (levorotatory-NG-nitroarginine), ATP-sensitive potassium channels (glibenclamide), and cyclic adenosine monophosphate (SQ22536). In high K+/Ca2+-free Kreb’s solution containing 0.01 mmol/L egtazic acid, resveratrol and genistein reduced the contractile responses of CaCl2, and shifted its cumulative concentration-response curves rightward.
CONCLUSION: Resveratrol and genistein relax gastrointestinal smooth muscle viaα-adrenergic receptors, nitric oxide and cyclic adenosine monophosphate pathways, ATP-sensitive potassium channels, and inhibition of L-type Ca2+ channels.
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MESH Headings
- Animals
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/metabolism
- Cyclic AMP/metabolism
- Dose-Response Relationship, Drug
- Duodenum/drug effects
- Duodenum/metabolism
- Female
- Gastric Mucosa/metabolism
- Gastrointestinal Motility/drug effects
- Genistein/pharmacology
- In Vitro Techniques
- KATP Channels/agonists
- KATP Channels/metabolism
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/metabolism
- Nitric Oxide/metabolism
- Phytoestrogens/pharmacology
- Rats, Sprague-Dawley
- Receptors, Adrenergic, alpha/drug effects
- Receptors, Adrenergic, alpha/metabolism
- Resveratrol
- Signal Transduction/drug effects
- Stilbenes/pharmacology
- Stomach/drug effects
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4
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Crocini C, Coppini R, Ferrantini C, Pavone FS, Sacconi L. Functional cardiac imaging by random access microscopy. Front Physiol 2014; 5:403. [PMID: 25368580 PMCID: PMC4202699 DOI: 10.3389/fphys.2014.00403] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/29/2014] [Indexed: 11/22/2022] Open
Abstract
Advances in the development of voltage sensitive dyes and Ca2+ sensors in combination with innovative microscopy techniques allowed researchers to perform functional measurements with an unprecedented spatial and temporal resolution. At the moment, one of the shortcomings of available technologies is their incapability of imaging multiple fast phenomena while controlling the biological determinants involved. In the near future, ultrafast deflectors can be used to rapidly scan laser beams across the sample, performing optical measurements of action potential and Ca2+ release from multiple sites within cardiac cells and tissues. The same scanning modality could also be used to control local Ca2+ release and membrane electrical activity by activation of caged compounds and light-gated ion channels. With this approach, local Ca2+ or voltage perturbations could be induced, simulating arrhythmogenic events, and their impact on physiological cell activity could be explored. The development of this optical methodology will provide fundamental insights in cardiac disease, boosting new therapeutic strategies, and, more generally, it will represent a new approach for the investigation of the physiology of excitable cells.
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Affiliation(s)
- Claudia Crocini
- European Laboratory for Non-Linear Spectroscopy (LENS) Florence, Italy
| | - Raffaele Coppini
- Division of Pharmacology, Department "NeuroFarBa," University of Florence Florence, Italy
| | - Cecilia Ferrantini
- Division of Physiology, Department of Experimental and Clinical Medicine, University of Florence Florence, Italy
| | - Francesco S Pavone
- European Laboratory for Non-Linear Spectroscopy (LENS) Florence, Italy ; Department of Physics and Astronomy, University of Florence Sesto Fiorentino, Italy ; National Research Council, National Institute of Optics Florence, Italy
| | - Leonardo Sacconi
- European Laboratory for Non-Linear Spectroscopy (LENS) Florence, Italy ; National Research Council, National Institute of Optics Florence, Italy
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5
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Yoon J, Choi M, Ku T, Choi WJ, Choi C. Optical induction of muscle contraction at the tissue scale through intrinsic cellular amplifiers. JOURNAL OF BIOPHOTONICS 2014; 7:597-606. [PMID: 23650149 DOI: 10.1002/jbio.201200246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 02/03/2013] [Accepted: 03/03/2013] [Indexed: 06/02/2023]
Abstract
The smooth muscle cell is the principal component responsible for involuntary control of visceral organs, including vascular tonicity, secretion, and sphincter regulation. It is known that the neurotransmitters released from nerve endings increase the intracellular Ca(2+) level in smooth muscle cells followed by muscle contraction. We herein report that femtosecond laser pulses focused on the diffraction-limited volume can induce intracellular Ca(2+) increases in the irradiated smooth muscle cell without neurotransmitters, and locally increased intracellular Ca(2+) levels are amplified by calcium-induced calcium-releasing mechanisms through the ryanodine receptor, a Ca(2+) channel of the endoplasmic reticulum. The laser-induced Ca(2+) increases propagate to adjacent cells through gap junctions. Thus, ultrashort-pulsed lasers can induce smooth muscle contraction by controlling Ca(2+), even with optical stimulation of the diffraction-limited volume. This optical method, which leads to reversible and reproducible muscle contraction, can be used in research into muscle dynamics, neuromuscular disease treatment, and nanorobot control.
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Affiliation(s)
- Jonghee Yoon
- Department of Bio and Brain Engineering, KAIST, Daejeon, Korea; KAIST Institute for Optical Science and Technology, KAIST, Daejeon, Korea
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6
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Karakhim SO. Mathematical modeling of calcium homeostasis in smooth muscle cells while activity of plasma membrane calcium pump is modulated. UKRAINIAN BIOCHEMICAL JOURNAL 2013. [DOI: 10.15407/ubj85.05.177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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7
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van Breemen C, Fameli N, Evans AM. Pan-junctional sarcoplasmic reticulum in vascular smooth muscle: nanospace Ca2+ transport for site- and function-specific Ca2+ signalling. J Physiol 2013; 591:2043-54. [PMID: 23339179 DOI: 10.1113/jphysiol.2012.246348] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
This review focuses on how smooth muscle sarcoplasmic reticulum (SR), the major releasable Ca(2+) store in these cells, performs its many functions by communicating with the plasma membrane (PM) and other organelles across cytoplasmic nanospaces, defined by membrane-membrane junctions less than 50 nm across. In spite of accumulating evidence in favour of the view that cytoplasmic nanospaces are a prerequisite for effective control of diverse cellular functions, our current understanding of how smooth muscle cells accomplish site- and function-specific Ca(2+) signalling remains in its infancy. We first present evidence in support of the view that effective Ca(2+) signalling depends on the restricted diffusion of Ca(2+) within cytoplasmic nanospaces. We then develop an evidence-based model of the smooth muscle SR - the 'pan-junctional SR' model - that incorporates a network of tubules and quilts that are capable of auto-regulating their Ca(2+) content and determining junctional [Ca(2+)]i through loading and unloading at membrane-membrane nanojunctions. Thereby, we provide a novel working hypothesis in order to inform future investigation into the control of a variety of cellular functions by local Ca(2+) signals at junctional nanospaces, from contraction and energy metabolism to nuclear transcription. Based on the current literature, we discuss the molecular mechanisms whereby the SR mediates these multiple functions through the interaction of ion channels and pumps embedded in apposing membranes within inter-organellar junctions. We finally highlight the fact that although most current hypotheses are qualitatively supported by experimental data, solid quantitative simulations are seriously lacking. Considering that at physiological concentrations the number of calcium ions in a typical junctional nanospace between the PM and SR is of the order of 1, ion concentration variability plays a major role as the currency of information transfer and stochastic quantitative modelling will be required to both test and develop working hypotheses.
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8
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Halidi N, Boittin FX, Bény JL, Meister JJ. Propagation of fast and slow intercellular Ca2+ waves in primary cultured arterial smooth muscle cells. Cell Calcium 2011; 50:459-67. [DOI: 10.1016/j.ceca.2011.08.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Revised: 08/02/2011] [Accepted: 08/02/2011] [Indexed: 11/30/2022]
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9
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LI YM, JI GJ. Evolution in Research of Ryanodine Receptors and Its Subtype 2 Regulators*. PROG BIOCHEM BIOPHYS 2011. [DOI: 10.3724/sp.j.1206.2010.00518] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Povstyan OV, Harhun MI, Gordienko DV. Ca2+ entry following P2X receptor activation induces IP3 receptor-mediated Ca2+ release in myocytes from small renal arteries. Br J Pharmacol 2011; 162:1618-38. [PMID: 21175582 PMCID: PMC3057298 DOI: 10.1111/j.1476-5381.2010.01169.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 11/04/2010] [Accepted: 11/25/2010] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE P2X receptors mediate sympathetic control and autoregulation of the renal circulation triggering contraction of renal vascular smooth muscle cells (RVSMCs) via an elevation of intracellular Ca(2+) concentration ([Ca(2+) ](i) ). Although it is well-appreciated that the myocyte Ca(2+) signalling system is composed of microdomains, little is known about the structure of the [Ca(2+) ](i) responses induced by P2X receptor stimulation in vascular myocytes. EXPERIMENTAL APPROACHES Using confocal microscopy, perforated-patch electrical recordings, immuno-/organelle-specific staining, flash photolysis and RT-PCR analysis we explored, at the subcellular level, the Ca(2+) signalling system engaged in RVSMCs on stimulation of P2X receptors with the selective agonist αβ-methylene ATP (αβ-meATP). KEY RESULTS RT-PCR analysis of single RVSMCs showed the presence of genes encoding inositol 1,4,5-trisphosphate receptor type 1(IP(3) R1) and ryanodine receptor type 2 (RyR2). The amplitude of the [Ca(2+) ](i) transients depended on αβ-meATP concentration. Depolarization induced by 10 µmol·L(-1) αβ-meATP triggered an abrupt Ca(2+) release from sub-plasmalemmal ('junctional') sarcoplasmic reticulum enriched with IP(3) Rs but poor in RyRs. Depletion of calcium stores, block of voltage-gated Ca(2+) channels (VGCCs) or IP(3) Rs suppressed the sub-plasmalemmal [Ca(2+) ](i) upstroke significantly more than block of RyRs. The effect of calcium store depletion or IP(3) R inhibition on the sub-plasmalemmal [Ca(2+) ](i) upstroke was attenuated following block of VGCCs. CONCLUSIONS AND IMPLICATIONS Depolarization of RVSMCs following P2X receptor activation induces IP(3) R-mediated Ca(2+) release from sub-plasmalemmal ('junctional') sarcoplasmic reticulum, which is activated mainly by Ca(2+) influx through VGCCs. This mechanism provides convergence of signalling pathways engaged in electromechanical and pharmacomechanical coupling in renal vascular myocytes.
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MESH Headings
- Adenosine Triphosphate/analogs & derivatives
- Adenosine Triphosphate/metabolism
- Adenosine Triphosphate/pharmacology
- Animals
- Calcium/metabolism
- Calcium Channels/metabolism
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Kidney/blood supply
- Male
- Muscle Cells/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/metabolism
- Purinergic P2X Receptor Agonists/pharmacology
- Rats
- Rats, Inbred WKY
- Receptors, Purinergic P2X/metabolism
- Renal Artery/metabolism
- Ryanodine Receptor Calcium Release Channel/genetics
- Sarcoplasmic Reticulum/metabolism
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Affiliation(s)
- Oleksandr V Povstyan
- Division of Basic Medical Sciences, St. George's, University of London, London, UK
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11
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Abstract
The sarcoplasmic reticulum (SR) of smooth muscles presents many intriguing facets and questions concerning its roles, especially as these change with development, disease, and modulation of physiological activity. The SR's function was originally perceived to be synthetic and then that of a Ca store for the contractile proteins, acting as a Ca amplification mechanism as it does in striated muscles. Gradually, as investigators have struggled to find a convincing role for Ca-induced Ca release in many smooth muscles, a role in controlling excitability has emerged. This is the Ca spark/spontaneous transient outward current coupling mechanism which reduces excitability and limits contraction. Release of SR Ca occurs in response to inositol 1,4,5-trisphosphate, Ca, and nicotinic acid adenine dinucleotide phosphate, and depletion of SR Ca can initiate Ca entry, the mechanism of which is being investigated but seems to involve Stim and Orai as found in nonexcitable cells. The contribution of the elemental Ca signals from the SR, sparks and puffs, to global Ca signals, i.e., Ca waves and oscillations, is becoming clearer but is far from established. The dynamics of SR Ca release and uptake mechanisms are reviewed along with the control of luminal Ca. We review the growing list of the SR's functions that still includes Ca storage, contraction, and relaxation but has been expanded to encompass Ca homeostasis, generating local and global Ca signals, and contributing to cellular microdomains and signaling in other organelles, including mitochondria, lysosomes, and the nucleus. For an integrated approach, a review of aspects of the SR in health and disease and during development and aging are also included. While the sheer versatility of smooth muscle makes it foolish to have a "one model fits all" approach to this subject, we have tried to synthesize conclusions wherever possible.
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Affiliation(s)
- Susan Wray
- Department of Physiology, School of Biomedical Sciences, University of Liverpool, Liverpool, Merseyside L69 3BX, United Kingdom.
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12
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Chen Z, Li Z, Wei B, Yin W, Xu T, Kotlikoff MI, Ji G. FKBP12.6-knockout mice display hyperinsulinemia and resistance to high-fat diet-induced hyperglycemia. FASEB J 2009; 24:357-63. [PMID: 19805579 DOI: 10.1096/fj.09-138446] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
FK506 binding protein 12.6 kDa (FKBP12.6), a protein that regulates ryanodine Ca(2+) release channels, may act as an important regulator of insulin secretion. In this study, the role of FKBP12.6 in the control of insulin secretion and blood glucose is clarified using FKBP12.6(-/-) mice. FKBP12.6(-/-) mice showed significant fed hyperinsulinemia but exhibited normoglycemia, fasting normoinsulinemia, and normal body weight compared with wild-type (WT) littermate control mice. Deletion of FKBP12.6 resulted in enhanced glucose-stimulated insulin secretion (GSIS) both in vivo and in vitro, a result that is due to enhanced glucose-induced islet Ca(2+) elevation. After a high-fat dietary challenge (HF diet) for 3 mo, FKBP12.6(-/-) mice displayed higher body weight, hyperinsulinemia, and lower fed blood glucose concentrations compared with WT mice. FKBP12.6(-/-) mice displayed hyperinsulinemia, and resistance to HF diet-induced hyperglycemia, suggesting that FKBP12.6 plays an important role in insulin secretion and blood glucose control, and raising the possibility that it may be a potential therapeutic target for the treatment of type 2 diabetes.
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Affiliation(s)
- Zheng Chen
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
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13
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Membrane depolarization causes a direct activation of G protein-coupled receptors leading to local Ca2+ release in smooth muscle. Proc Natl Acad Sci U S A 2009; 106:11418-23. [PMID: 19549818 DOI: 10.1073/pnas.0813307106] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Membrane depolarization activates voltage-dependent Ca(2+) channels (VDCCs) inducing Ca(2+) release via ryanodine receptors (RyRs), which is obligatory for skeletal and cardiac muscle contraction and other physiological responses. However, depolarization-induced Ca(2+) release and its functional importance as well as underlying signaling mechanisms in smooth muscle cells (SMCs) are largely unknown. Here we report that membrane depolarization can induce RyR-mediated local Ca(2+) release, leading to a significant increase in the activity of Ca(2+) sparks and contraction in airway SMCs. The increased Ca(2+) sparks are independent of VDCCs and the associated extracellular Ca(2+) influx. This format of local Ca(2+) release results from a direct activation of G protein-coupled, M(3) muscarinic receptors in the absence of exogenous agonists, which causes activation of Gq proteins and phospholipase C, and generation of inositol 1,4,5-triphosphate (IP(3)), inducing initial Ca(2+) release through IP(3) receptors and then further Ca(2+) release via RyR2 due to a local Ca(2+)-induced Ca(2+) release process. These findings demonstrate an important mechanism for Ca(2+) signaling and attendant physiological function in SMCs.
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14
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Frei E, Hofmann F, Wegener JW. Phospholipase C mediated Ca2+ signals in murine urinary bladder smooth muscle. Eur J Pharmacol 2009; 610:106-9. [PMID: 19303404 DOI: 10.1016/j.ejphar.2009.03.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Revised: 02/27/2009] [Accepted: 03/10/2009] [Indexed: 10/21/2022]
Abstract
Muscarinic stimulation of urinary bladder induces contraction via an increase in intracellular Ca(2+) concentration that results from Ca(2+) influx through Ca(2+) channels and/or IP(3)-mediated Ca(2+) release controlled by phospholipase C (PLC) signalling. The significance of PLC/IP(3) signalling in this cascade has recently been questioned because PLC inhibitors were without effect on carbachol-induced contractions in detrusor muscle strips. However, PLC/IP(3)-mediated Ca(2+) release was clearly observed in recordings of Ca(2+) signals in isolated myocytes. Therefore, we investigated the presence of PLC/IP(3)-dependent Ca(2+) release by directly monitoring Ca(2+) signals in intact detrusor muscle strips. Concomitant Ca(2+) signals from Ca(2+) channel activity were eliminated by the Ca(2+) channel antagonist isradipine (3 microM) or by the use of muscles from Ca(v)1.2 channel-deficient (SMACKO) mice. In absence of Ca(2+) channel activity, carbachol elicited contractions and Ca(2+) signals in muscles from wild type and SMACKO mice that were inhibited by the PLC inhibitor U73122 (10 microM). The results show that PLC/IP(3)-dependent Ca(2+) release is activated by stimulation with carbachol in urinary bladder smooth muscle but has a minor contribution to overall carbachol-induced Ca(2+) signals.
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Affiliation(s)
- Eva Frei
- Institut für Pharmakologie und Toxikologie, TU München, Biedersteiner Str. 29, D-80802 München, Germany
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15
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Takahashi N, Shiomi H, Kushida N, Liu F, Ishibashi K, Yanagida T, Shishido K, Aikawa K, Yamaguchi O. Obstruction alters muscarinic receptor-coupled RhoA/Rho-kinase pathway in the urinary bladder of the rat. Neurourol Urodyn 2009; 28:257-62. [DOI: 10.1002/nau.20625] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Scherschel JA, Rubart M. Cardiovascular imaging using two-photon microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2008; 14:492-506. [PMID: 18986603 PMCID: PMC2583458 DOI: 10.1017/s1431927608080835] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Two-photon excitation microscopy has become the standard technique for high resolution deep tissue and intravital imaging. It provides intrinsic three-dimensional resolution in combination with increased penetration depth compared to single-photon confocal microscopy. This article will describe the basic physical principles of two-photon excitation and will review its multiple applications to cardiovascular imaging, including second harmonic generation and fluorescence laser scanning microscopy. In particular, the capability and limitations of multiphoton microscopy to assess functional heterogeneity on a cellular scale deep within intact, Langendorff-perfused hearts are demonstrated. It will also discuss the use of two-photon excitation-induced release of caged compounds for the study of intracellular calcium signaling and intercellular dye transfer.
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Affiliation(s)
- John A Scherschel
- Department of Pediatrics, Division of Cardiology, Wells Center for Pediatric Research, 1044 West Walnut Street, Indianapolis, IN 46202, USA
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Abstract
The calcium ion (Ca(2+)) is the simplest and most versatile intracellular messenger known. The discovery of Ca(2+) sparks and a related family of elementary Ca(2+) signaling events has revealed fundamental principles of the Ca(2+) signaling system. A newly appreciated "digital" subsystem consisting of brief, high Ca(2+) concentration over short distances (nanometers to microns) comingles with an "analog" global Ca(2+) signaling subsystem. Over the past 15 years, much has been learned about the theoretical and practical aspects of spark formation and detection. The quest for the spark mechanisms [the activation, coordination, and termination of Ca(2+) release units (CRUs)] has met unexpected challenges, however, and raised vexing questions about CRU operation in situ. Ample evidence shows that Ca(2+) sparks catalyze many high-threshold Ca(2+) processes involved in cardiac and skeletal muscle excitation-contraction coupling, vascular tone regulation, membrane excitability, and neuronal secretion. Investigation of Ca(2+) sparks in diseases has also begun to provide novel insights into hypertension, cardiac arrhythmias, heart failure, and muscular dystrophy. An emerging view is that spatially and temporally patterned activation of the digital subsystem confers on intracellular Ca(2+) signaling an exquisite architecture in space, time, and intensity, which underpins signaling efficiency, stability, specificity, and diversity. These recent advances in "sparkology" thus promise to unify the simplicity and complexity of Ca(2+) signaling in biology.
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Affiliation(s)
- Heping Cheng
- Institute of Molecular Medicine, National Laboratory of Biomembrane and Membrane Biotechnology, Peking University, Beijing, China.
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18
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Shirokova N, Niggli E. Studies of RyR function in situ. Methods 2008; 46:183-93. [PMID: 18848990 DOI: 10.1016/j.ymeth.2008.09.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Accepted: 09/12/2008] [Indexed: 10/21/2022] Open
Abstract
The ryanodine receptors (RyRs) are intracellular Ca2+ release channels of the sarcoplasmic reticulum (SR) involved in many cellular responses, including muscle excitation-contraction coupling. Multiple biochemical and biophysical methods are available to study RyR functions. However, most of them are somewhat limited because they can only be used to examine channels which are purified from the SR and no longer in their natural environment. In this review we discuss optical methods for studying RyR functions in situ. We describe several techniques for the investigation of local (microscopic) intracellular Ca2+ signals (a.k.a Ca2+ sparks) by means of confocal microscopy and flash photolysis of caged compounds. We discuss how these studies can and will continue to contribute to our understanding of RyR function in physiological and pathological conditions.
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Affiliation(s)
- Natalia Shirokova
- Department of Pharmacology & Physiology, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA.
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19
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Colleran PN, Behnke BJ, Wilkerson MK, Donato AJ, Delp MD. Simulated microgravity alters rat mesenteric artery vasoconstrictor dynamics through an intracellular Ca2+release mechanism. Am J Physiol Regul Integr Comp Physiol 2008; 294:R1577-85. [DOI: 10.1152/ajpregu.00084.2008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous work has shown that orthostatic hypotension associated with cardiovascular deconditioning results from inadequate peripheral vasoconstriction. We used the hindlimb-unloaded (HU) rat in this study as a model to induce cardiovascular deconditioning. The purpose of this study was to test the hypothesis that 14 days of HU diminishes vasoconstrictor responsiveness of mesenteric resistance arteries. Mesenteric resistance arteries from control ( n = 43) and HU ( n = 44) rats were isolated, cannulated, and pressurized to 108 cm H2O for in vitro experimentation. Myogenic (intralumenal pressure ranging from 30 to 180 cm H2O), KCl (2–100 mM), norepinephrine (NE, 10−9–10−4M) and caffeine (1–20 mM) induced vasoconstriction, as well as the temporal dynamics of vasoconstriction to NE, were determined. The active myogenic and passive pressure responses were unaltered by HU when pressures remained within physiological range. However, vasoconstrictor responses to KCl, NE, and caffeine were diminished by HU, as well as the rate of constriction to NE (C, 14.8 ± 3.6 μm/s vs. HU 7.6 ± 1.8 μm/s). Expression of sarcoplasmic reticulum Ca2+ATPase 2 and ryanodine 3 receptor mRNA was unaffected by HU, while ryanodine 2 receptor mRNA and protein expression were diminished in mesenteric arteries from HU rats. These data suggest that HU-induced and microgravity-associated orthostatic intolerance may be due, in part, to an attenuated vasoconstrictor responsiveness of mesenteric resistance arteries resulting from a diminished ryanodine 2 receptor Ca2+release mechanism.
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Christ GJ, Andersson KE. Rho-kinase and effects of Rho-kinase inhibition on the lower urinary tract. Neurourol Urodyn 2008; 26:948-54. [PMID: 17696159 DOI: 10.1002/nau.20475] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Altered smooth muscle cell contractility/tone contributes, at least in part, to the lower urinary tract symptoms (LUTS) seen in men with benign prostatic obstruction (BPO). Accordingly, many of the therapies to date have focused largely on blockade of individual membrane receptors to diminish smooth muscle contractility and provide symptomatic relief. This pharmacologic approach has been associated with variable results, limited efficacy, and untoward side effects. Such limited clinical success is not surprising given the plethora of neurotransmitters, neuromodulators, and hormones that are now known to modulate LUT smooth muscle cell tone. In the pursuit of improved treatment options, more recent investigations have focused attention on intracellular signal transduction events that represent convergence points for membrane receptor activation. In particular, calcium sensitization and the role of the Rho-kinase pathway has received much attention. In this report, we review the literature on the role of the Rho-kinase pathway in the modulation of LUT smooth muscle cell tone. In short, the available data support an important role for Rho-kinase in the physiologic and pathophysiologic regulation of LUT smooth muscle cell tone. Rho-kinase inhibitors thus appear to represent a potentially attractive therapeutic possibility for the treatment of LUTS.
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Affiliation(s)
- George J Christ
- Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
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21
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Gordienko DV, Harhun MI, Kustov MV, Pucovský V, Bolton TB. Sub-plasmalemmal [Ca2+]i upstroke in myocytes of the guinea-pig small intestine evoked by muscarinic stimulation: IP3R-mediated Ca2+ release induced by voltage-gated Ca2+ entry. Cell Calcium 2007; 43:122-41. [PMID: 17570487 PMCID: PMC2268754 DOI: 10.1016/j.ceca.2007.04.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Revised: 03/29/2007] [Accepted: 04/20/2007] [Indexed: 11/23/2022]
Abstract
Membrane depolarization triggers Ca2+ release from the sarcoplasmic reticulum (SR) in skeletal muscles via direct interaction between the voltage-gated L-type Ca2+ channels (the dihydropyridine receptors; VGCCs) and ryanodine receptors (RyRs), while in cardiac muscles Ca2+ entry through VGCCs triggers RyR-mediated Ca2+ release via a Ca2+-induced Ca2+ release (CICR) mechanism. Here we demonstrate that in phasic smooth muscle of the guinea-pig small intestine, excitation evoked by muscarinic receptor activation triggers an abrupt Ca2+ release from sub-plasmalemmal (sub-PM) SR elements enriched with inositol 1,4,5-trisphosphate receptors (IP3Rs) and poor in RyRs. This was followed by a lesser rise, or oscillations in [Ca2+]i. The initial abrupt sub-PM [Ca2+]i upstroke was all but abolished by block of VGCCs (by 5 μM nicardipine), depletion of intracellular Ca2+ stores (with 10 μM cyclopiazonic acid) or inhibition of IP3Rs (by 2 μM xestospongin C or 30 μM 2-APB), but was not affected by block of RyRs (by 50–100 μM tetracaine or 100 μM ryanodine). Inhibition of either IP3Rs or RyRs attenuated phasic muscarinic contraction by 73%. Thus, in contrast to cardiac muscles, excitation–contraction coupling in this phasic visceral smooth muscle occurs by Ca2+ entry through VGCCs which evokes an initial IP3R-mediated Ca2+ release activated via a CICR mechanism.
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Affiliation(s)
- D V Gordienko
- Division of Basic Medical Sciences, Ion Channels and Cell Signalling Centre, St. George's University of London, UK.
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22
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Kanai A, Roppolo J, Ikeda Y, Zabbarova I, Tai C, Birder L, Griffiths D, de Groat W, Fry C. Origin of spontaneous activity in neonatal and adult rat bladders and its enhancement by stretch and muscarinic agonists. Am J Physiol Renal Physiol 2006; 292:F1065-72. [PMID: 17107944 PMCID: PMC3033037 DOI: 10.1152/ajprenal.00229.2006] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study examined the origin of spontaneous activity in neonatal and adult rat bladders and the effect of stretch and muscarinic agonists and antagonists on spontaneous activity. Rats were anesthetized and their bladders were excised, cannulated, and loaded with voltage- and Ca(2+)-sensitive dyes. Intracellular Ca(2+) and membrane potential transients were mapped using photodiode arrays in whole bladders, bladder sheets, or cross-section preparations at 37 degrees C. Intravesical pressure was recorded from whole bladders. In neonatal bladders and sheets, spontaneous Ca(2+) and electrical signals arose at a site near the dome and spread in a coordinated manner throughout the bladder with different dome-to-neck conduction velocities (Ca(2+): 3.7 +/- 0.4 mm/s; membrane potential: 46.2 +/- 3.1 mm/s). In whole bladders, optical signals were associated with spontaneous contractions (10-20 cmH(2)O). By contrast, in adult bladders spontaneous Ca(2+) and electrical activity was uncoordinated, originating at multiple sites and was associated with smaller (2-5 cmH(2)O) contractions. Spontaneous contractions and optical signals were insensitive to tetrodotoxin (2 muM) but were blocked by nifedipine (10 muM). Stretch or low carbachol concentrations (50 nM) applied to neonatal whole bladders enhanced the amplitude (to 20-35 cmH(2)O) of spontaneous activity, which was blocked by atropine. Bladder cross sections revealed that Ca(2+) and membrane potential transients produced by stretch or carbachol began near the urothelial-suburothelial interface and then spread to the detrusor. In conclusion, spontaneous activity in neonatal bladders, unlike activity in adult bladders, is highly organized, originating in the urothelium-suburothelium near the dome. Activity is enhanced by stretch or carbachol and this enhancement is blocked by atropine. It is hypothesized that acetylcholine is released from the urothelium during bladder filling to enhance spontaneous activity.
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Affiliation(s)
- A Kanai
- Department of Medicine, University of Pittsburgh School of Medicine, A1224 Scaife Hall, Pittsburgh, PA 15261, USA.
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23
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Takano T, Nedergaard M. DM-nitrophen provides physiologically significant increases of intracellular [Ca2+] in the presence of Mg2+. Cell Calcium 2006; 41:503-4. [PMID: 17055047 DOI: 10.1016/j.ceca.2006.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Revised: 09/08/2006] [Accepted: 09/14/2006] [Indexed: 10/24/2022]
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Amberg GC, Navedo MF, Santana LF. On the loose: uncaging Ca2+ -induced Ca2+ release in smooth muscle. ACTA ACUST UNITED AC 2006; 127:221-3. [PMID: 16505144 PMCID: PMC2151499 DOI: 10.1085/jgp.200609510] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Gregory C Amberg
- Department of Physiology and Biophsyics, University of Washington School of Medicine, Seattle, 98195, USA
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