1
|
Nelson C, Dichiera AM, Brauner CJ. Developing rainbow trout (Oncorhynchus mykiss) lose branchial plasma accessible carbonic anhydrase expression with hatch and the transition to pH-sensitive, adult hemoglobin polymorphs. J Comp Physiol B 2024; 194:537-543. [PMID: 38698121 DOI: 10.1007/s00360-024-01557-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 03/03/2024] [Accepted: 04/15/2024] [Indexed: 05/05/2024]
Abstract
Salmonids possess a unique respiratory system comprised of three major components: highly pH-sensitive hemoglobins, red blood cell (RBC) intracellular pH (pHi) protection, and a heterogeneous distribution of plasma accessible carbonic anhydrase (paCA), specifically with absence of paCA at the gills. These characteristics are thought to have evolved to enhance oxygen unloading to the tissues while protecting uptake at the gills. Our knowledge of this system is detailed in adults, but little is known about it through development. Developing rainbow trout (Oncorhynchus mykiss) express embryonic RBCs containing hemoglobins that are relatively insensitive to pH; however, availability of gill paCA and RBC pHi protection is unknown. We show that pre-hatch rainbow trout express gill paCA, which is lost in correlation with the emergence of highly pH-sensitive adult hemoglobins and RBC pHi protection. Rainbow trout therefore exhibit a switch in respiratory strategy with hatch. We conclude that gill paCA likely represents an embryonic trait in rainbow trout and is constrained in adults due to their highly pH-sensitive hemoglobins.
Collapse
Affiliation(s)
| | | | - Colin J Brauner
- University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| |
Collapse
|
2
|
Harter TS, Dichiera AM, Esbaugh AJ. The physiological significance of plasma-accessible carbonic anhydrase in the respiratory systems of fishes. J Comp Physiol B 2024:10.1007/s00360-024-01562-4. [PMID: 38842596 DOI: 10.1007/s00360-024-01562-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/26/2024] [Accepted: 05/13/2024] [Indexed: 06/07/2024]
Abstract
Carbonic anhydrase (CA) activity is ubiquitously found in all vertebrate species, tissues and cellular compartments. Most species have plasma-accessible CA (paCA) isoforms at the respiratory surfaces, where the enzyme catalyzes the conversion of plasma bicarbonate to carbon dioxide (CO2) that can be excreted by diffusion. A notable exception are the teleost fishes that appear to lack paCA at their gills. The present review: (i) recapitulates the significance of CA activity and distribution in vertebrates; (ii) summarizes the current evidence for the presence or absence of paCA at the gills of fishes, from the basal cyclostomes to the derived teleosts and extremophiles such as the Antarctic icefishes; (iii) explores the contribution of paCA to organismal CO2 excretion in fishes; and (iv) the functional significance of its absence at the gills, for the specialized system of O2 transport in most teleosts; (v) outlines the multiplicity and isoform distribution of membrane-associated CAs in fishes and methodologies to determine their plasma-accessible orientation; and (vi) sketches a tentative time line for the evolutionary dynamics of branchial paCA distribution in the major groups of fishes. Finally, this review highlights current gaps in the knowledge on branchial paCA function and provides recommendations for future work.
Collapse
Affiliation(s)
- Till S Harter
- Department of Biology, McMaster University, Hamilton, ON, L8S 4K1, Canada.
| | - Angelina M Dichiera
- College of William and Mary, Virginia Institute of Marine Science, Gloucester Point, VA, 23062, USA
| | - Andrew J Esbaugh
- Marine Science Institute, University of Texas at Austin, Port Aransas, TX, 78373, USA
| |
Collapse
|
3
|
Nelson C, Standen EM, Allen PJ, Brauner CJ. An investigation of gill and blood carbonic anhydrase characteristics in three basal actinopterygian species: alligator gar (Atractosteus spatula), white sturgeon (Acipenser transmontanus) and Senegal bichir (Polypterus senegalus). J Comp Physiol B 2024; 194:155-166. [PMID: 38459993 DOI: 10.1007/s00360-024-01539-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/22/2023] [Accepted: 01/19/2024] [Indexed: 03/11/2024]
Abstract
Many teleosts possess a unique set of respiratory characteristics allowing enhanced oxygen unloading to the tissues during stress. This system comprises three major components: highly pH sensitive haemoglobins (large Bohr and Root effects), rapid red blood cell (RBC) intracellular pH (pHi) protection, and a heterogeneous distribution of membrane-bound plasma-accessible carbonic anhydrase (paCA; absence in the gills). The first two components have received considerable research effort; however, the evolutionary loss of branchial paCA has received little attention. In the current study, we investigated the availability of branchial membrane-bound CA, along with several other CA-related characteristics in species belonging to three basal actinopterygian groups: the Lepisosteiformes, Acipenseriformes and Polypteriformes to assess the earlier hypothesis that Root effect haemoglobins constrain branchial paCA availability. We present the first evidence suggesting branchial membrane-bound CA presence in a basal actinopterygian species: the Senegal bichir (Polypterus senegalus) and show that like the teleosts, white sturgeon (Acipenser transmontanus) and alligator gar (Atractosteus spatula) do not possess branchial membrane-bound CA. We discuss the varying respiratory strategies for these species and propose that branchial paCA may have been lost much earlier than previously thought, likely in relation to the changes in haemoglobin buffer capacity associated with the increasing magnitude of the Bohr effect. The findings described here represent an important advancement in our understanding of the evolution of the unique system of enhanced oxygen unloading thought to be present in most teleosts, a group that encompasses half of all vertebrates.
Collapse
Affiliation(s)
| | | | - Peter J Allen
- Mississippi State University, Mississippi, 39762, USA
| | - Colin J Brauner
- University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| |
Collapse
|
4
|
Harter TS, Smith EA, Tresguerres M. A novel perspective on the evolutionary loss of plasma-accessible carbonic anhydrase at the teleost gill. J Exp Biol 2023; 226:jeb246016. [PMID: 37694374 PMCID: PMC10629482 DOI: 10.1242/jeb.246016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 08/31/2023] [Indexed: 09/12/2023]
Abstract
The gills of most teleost fishes lack plasma-accessible carbonic anhydrase (paCA) that could participate in CO2 excretion. We tested the prevailing hypothesis that paCA would interfere with red blood cell (RBC) intracellular pH regulation by β-adrenergic sodium-proton exchangers (β-NHE) that protect pH-sensitive haemoglobin-oxygen (Hb-O2) binding during an acidosis. In an open system that mimics the gills, β-NHE activity increased Hb-O2 saturation during a respiratory acidosis in the presence or absence of paCA, whereas the effect was abolished by NHE inhibition. However, in a closed system that mimics the tissue capillaries, paCA disrupted the protective effects of β-NHE activity on Hb-O2 binding. The gills are an open system, where CO2 generated by paCA can diffuse out and is not available to acidifying the RBCs. Therefore, branchial paCA in teleosts may not interfere with RBC pH regulation by β-NHEs, and other explanations for the evolutionary loss of the enzyme must be considered.
Collapse
Affiliation(s)
- Till S. Harter
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| | - Emma A. Smith
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| | - Martin Tresguerres
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| |
Collapse
|
5
|
Farrell AP. Getting to the heart of anatomical diversity and phenotypic plasticity: fish hearts are an optimal organ model in need of greater mechanistic study. J Exp Biol 2023; 226:jeb245582. [PMID: 37578108 DOI: 10.1242/jeb.245582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Natural selection has produced many vertebrate 'solutions' for the cardiac life-support system, especially among the approximately 30,000 species of fishes. For example, across species, fish have the greatest range for central arterial blood pressure and relative ventricular mass of any vertebrate group. This enormous cardiac diversity is excellent ground material for mechanistic explorations. Added to this species diversity is the emerging field of population-specific diversity, which is revealing that cardiac design and function can be tailored to a fish population's local environmental conditions. Such information is important to conservation biologists and ecologists, as well as physiologists. Furthermore, the cardiac structure and function of an individual adult fish are extremely pliable (through phenotypic plasticity), which is typically beneficial to the heart's function when environmental conditions are variable. Consequently, exploring factors that trigger cardiac remodelling with acclimation to new environments represents a marvellous opportunity for performing mechanistic studies that minimize the genetic differences that accompany cross-species comparisons. What makes the heart an especially good system for the investigation of phenotypic plasticity and species diversity is that its function can be readily evaluated at the organ level using established methodologies, unlike most other organ systems. Although the fish heart has many merits as an organ-level model to provide a mechanistic understanding of phenotypic plasticity and species diversity, bringing this potential to fruition will require productive research collaborations among physiologists, geneticists, developmental biologists and ecologists.
Collapse
|
6
|
Nelson C, Dichiera AM, Jung EH, Brauner CJ. An atlas of plasma-accessible carbonic anhydrase availability in the model teleost, the rainbow trout. J Comp Physiol B 2023; 193:293-305. [PMID: 37029801 DOI: 10.1007/s00360-023-01484-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/28/2023] [Accepted: 03/14/2023] [Indexed: 04/09/2023]
Abstract
The unique teleost oxygenation system that permits enhanced oxygen unloading during stress comprises three main characteristics: pH-sensitive haemoglobin, red blood cell (RBC) intracellular pH (pHi) protection, and a heterogeneous distribution of plasma-accessible carbonic anhydrase (paCA). A heterogeneous distribution of paCA is essential; its presence permits enhanced oxygen unloading during stress, while its absence at the gills maintains conditions for oxygen uptake by pH-sensitive haemoglobins. We hypothesised that paCA would be absent in all four gill arches, as has been previously indicated for arch two, and that paCA would be present in all other tissues. Through a suite of biochemical and molecular methods, we confirmed the absence of paCA from all four arches. We also found evidence for paCA in nine other tissues and a lack of paCA availability in the stomach. Expression was highly variable between tissues and suggests these differences may be associated with their respective metabolic activities. Additionally, we analysed the specific CA-IV isoform expressed within each tissue and showed almost complete separation of expression between tissues; CA-IVa was detected in the heart, brain, anterior intestine, and liver, whereas CA-IVb was detected in all intestine sections, pyloric caeca, kidney, and white muscle. This adds to a growing collection of work suggesting CA-IVa and b play divergent roles in gas exchange and ion/acid-base balance, respectively. The current study represents the first comprehensive atlas of paCA availability within the circulatory system of the model teleost, rainbow trout, and fills important gaps in our knowledge of this unique oxygenation system.
Collapse
Affiliation(s)
| | | | - Ellen H Jung
- University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Colin J Brauner
- University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| |
Collapse
|
7
|
Engelbrecht E, Kooistra T, Knipe RS. The Vasculature in Pulmonary Fibrosis. CURRENT TISSUE MICROENVIRONMENT REPORTS 2022; 3:83-97. [PMID: 36712832 PMCID: PMC9881604 DOI: 10.1007/s43152-022-00040-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/23/2022] [Indexed: 02/02/2023]
Abstract
Purpose of Review The current paradigm of idiopathic pulmonary fibrosis (IPF) pathogenesis involves recurrent injury to a sensitive alveolar epithelium followed by impaired repair responses marked by fibroblast activation and deposition of extracellular matrix. Multiple cell types are involved in this response with potential roles suggested by advances in single-cell RNA sequencing and lung developmental biology. Notably, recent work has better characterized the cell types present in the pulmonary endothelium and identified vascular changes in patients with IPF. Recent Findings Lung tissue from patients with IPF has been examined at single-cell resolution, revealing reductions in lung capillary cells and expansion of a population of vascular cells expressing markers associated with bronchial endothelium. In addition, pre-clinical models have demonstrated a fundamental role for aging and vascular permeability in the development of pulmonary fibrosis. Summary Mounting evidence suggests that the endothelium undergoes changes in the context of fibrosis, and these changes may contribute to the development and/or progression of pulmonary fibrosis. Additional studies will be needed to further define the functional role of these vascular changes.
Collapse
Affiliation(s)
| | - Tristan Kooistra
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Rachel S. Knipe
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| |
Collapse
|
8
|
Harter TS, Brauner CJ. Teleost red blood cells actively enhance the passive diffusion of oxygen that was discovered by August Krogh. Comp Biochem Physiol A Mol Integr Physiol 2021; 253:110855. [DOI: 10.1016/j.cbpa.2020.110855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 11/23/2020] [Accepted: 11/23/2020] [Indexed: 11/28/2022]
|
9
|
Ansaloni F, Gerdol M, Torboli V, Fornaini NR, Greco S, Giulianini PG, Coscia MR, Miccoli A, Santovito G, Buonocore F, Scapigliati G, Pallavicini A. Cold Adaptation in Antarctic Notothenioids: Comparative Transcriptomics Reveals Novel Insights in the Peculiar Role of Gills and Highlights Signatures of Cobalamin Deficiency. Int J Mol Sci 2021; 22:ijms22041812. [PMID: 33670421 PMCID: PMC7918649 DOI: 10.3390/ijms22041812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/04/2021] [Accepted: 02/08/2021] [Indexed: 01/13/2023] Open
Abstract
Far from being devoid of life, Antarctic waters are home to Cryonotothenioidea, which represent one of the fascinating cases of evolutionary adaptation to extreme environmental conditions in vertebrates. Thanks to a series of unique morphological and physiological peculiarities, which include the paradigmatic case of loss of hemoglobin in the family Channichthyidae, these fish survive and thrive at sub-zero temperatures. While some of the distinctive features of such adaptations have been known for decades, our knowledge of their genetic and molecular bases is still limited. We generated a reference de novo assembly of the icefish Chionodraco hamatus transcriptome and used this resource for a large-scale comparative analysis among five red-blooded Cryonotothenioidea, the sub-Antarctic notothenioid Eleginops maclovinus and seven temperate teleost species. Our investigation targeted the gills, a tissue of primary importance for gaseous exchange, osmoregulation, ammonia excretion, and its role in fish immunity. One hundred and twenty genes were identified as significantly up-regulated in Antarctic species and surprisingly shared by red- and white-blooded notothenioids, unveiling several previously unreported molecular players that might have contributed to the evolutionary success of Cryonotothenioidea in Antarctica. In particular, we detected cobalamin deficiency signatures and discussed the possible biological implications of this condition concerning hematological alterations and the heavy parasitic loads typically observed in all Cryonotothenioidea.
Collapse
Affiliation(s)
- Federico Ansaloni
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
- International School for Advanced Studies, 34136 Trieste, Italy
| | - Marco Gerdol
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
- Correspondence:
| | - Valentina Torboli
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
| | - Nicola Reinaldo Fornaini
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
- Department of Cell Biology, Charles University, 12800 Prague, Czech Republic
| | - Samuele Greco
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
| | - Piero Giulio Giulianini
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
| | - Maria Rosaria Coscia
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, 80131 Naples, Italy;
| | - Andrea Miccoli
- Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia, 01100 Viterbo, Italy; (A.M.); (F.B.); (G.S.)
| | | | - Francesco Buonocore
- Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia, 01100 Viterbo, Italy; (A.M.); (F.B.); (G.S.)
| | - Giuseppe Scapigliati
- Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia, 01100 Viterbo, Italy; (A.M.); (F.B.); (G.S.)
| | - Alberto Pallavicini
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
- Anton Dohrn Zoological Station, 80122 Naples, Italy
- National Institute of Oceanography and Experimental Geophysics, 34010 Trieste, Italy
| |
Collapse
|
10
|
Brauner CJ, Shartau RB, Damsgaard C, Esbaugh AJ, Wilson RW, Grosell M. Acid-base physiology and CO2 homeostasis: Regulation and compensation in response to elevated environmental CO2. FISH PHYSIOLOGY 2019. [DOI: 10.1016/bs.fp.2019.08.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
11
|
Knight K. Thin-blooded icefish relocate carbonic anhydrase to gill. J Exp Biol 2018. [DOI: 10.1242/jeb.193680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|