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Abstract
During water-land transition, ancient fishes acquired the ability to breathe air, but air-breathing engendered problems in nitrogenous waste excretion. Nitrogen is a fundamental component of amino acids, proteins, and nucleic acids, and the degradation of these nitrogen-containing compounds releases ammonia. Ammonia is toxic and must be removed. Fishes in water excrete ammonia as the major nitrogenous waste through gills, but gills of air-breathing fishes are modified for air-breathing or largely replaced by air-breathing organs. Notably, fishes emerged from water can no longer excrete ammonia effectively because of a lack of water to flush the gills. Hence, ancient fishes that participated in water-land transition must have developed means to deal with ammonia toxicity. Extant air-breathing fishes, particularly amphibious ones, can serve as models to examine adaptations which might have facilitated the emergence of ancient fishes from water. Some of these fishes can actively emerge from water and display complex behaviors on land, while a few can burrow into mud and survive for years during drought. Many of them are equipped with mechanisms to ameliorate ammonia toxicity during emersion. In this review, the mechanisms adopted by air-breathing fishes to deal with ammonia toxicity during emersion were organized into seven disparate strategies. In addition, eight extant air-breathing fishes with distinctive terrestrial behaviors and peculiar natural habitats were selected to describe in detail how these seven strategies could be adopted in disparate combinations to ameliorate ammonia toxicity during emersion.
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Hangzo H, Banerjee B, Saha S, Saha N. Ammonia stress under high environmental ammonia induces Hsp70 and Hsp90 in the mud eel, Monopterus cuchia. FISH PHYSIOLOGY AND BIOCHEMISTRY 2017; 43:77-88. [PMID: 27492114 DOI: 10.1007/s10695-016-0269-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 08/01/2016] [Indexed: 06/06/2023]
Abstract
The obligatory air-breathing mud eel (Monopterus cuchia) is frequently being challenged with high environmental ammonia (HEA) exposure in its natural habitats. The present study investigated the possible induction of heat shock protein 70 and 90 (hsp70, hsc70, hsp90α and hsp90β) genes and more expression of Hsp70 and Hsp90 proteins under ammonia stress in different tissues of the mud eel after exposure to HEA (50 mM NH4Cl) for 14 days. HEA resulted in significant accumulation of toxic ammonia in different body tissues and plasma, which was accompanied with the stimulation of oxidative stress in the mud eel as evidenced by more accumulation of malondialdehyde (MDA) and hydrogen peroxide (H2O2) during exposure to HEA. Further, hyper-ammonia stress led to significant increase in the levels of mRNA transcripts for inducible hsp70 and hsp90α genes and also their translated proteins in different tissues probably as a consequence of induction of hsp70 and hsp90α genes in the mud eel. However, hyper-ammonia stress was neither associated with any significant alterations in the levels of mRNA transcripts for constitutive hsc70 and hsp90β genes nor their translated proteins in any of the tissues studied. More abundance of Hsp70 and Hsp90α proteins might be one of the strategies adopted by the mud eel to defend itself from the ammonia-induced cellular damages under ammonia stress. Further, this is the first report of ammonia-induced induction of hsp70 and hsp90α genes under hyper-ammonia stress in any freshwater air-breathing teleost.
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Affiliation(s)
- Hnunlalliani Hangzo
- Biochemical Adaptation Laboratory, Department of Zoology, North-Eastern Hill University, Shillong, 793022, India
| | - Bodhisattwa Banerjee
- Biochemical Adaptation Laboratory, Department of Zoology, North-Eastern Hill University, Shillong, 793022, India
| | - Shrabani Saha
- Institute of Biotechnology, Amity University, Sector 125, Noida, 201303, India
| | - Nirmalendu Saha
- Biochemical Adaptation Laboratory, Department of Zoology, North-Eastern Hill University, Shillong, 793022, India.
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Liu J, Li F, Tang XD, Ma J, Mao M, Wu FZ, Bai SJ, Liu YY, Han CX, Li XX, Liu Y, Song YH, Wu ZY, Wang FY, Kang N. Sini powder () decoction alleviates mood disorder of insomnia by regulating cation-chloride cotransporters in hippocampus. Chin J Integr Med 2015:10.1007/s11655-015-2308-x. [PMID: 26597287 DOI: 10.1007/s11655-015-2308-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To investigate the mechanism of Sini Powder () decoction (SND) in the treatment of insomnia. METHODS The rats were randomly divided into four groups: control, model, SND-treated, and Estazolamtreated groups (n=15 in each group). Sleep deprivation (SD) rat model was established using the modifified multiple platform method for 14 h per day for 14 days, and the behavior of the rats were observed. Na-K-Cl-cotransporter (NKCC1) and K+/Cl- cotransporter (KCC2) in the hippocampus were tested by immunohistochemistry, real-time polymerase chain reaction, and western blot. RESULTS SD rats displayed anxiety-like behavior, which was alleviated by SND. The protein expressions of NKCC1 and KCC2 in the hippocampus were signifificantly decreased in SD rats compared with those in control rats (P<0.05); these proteins were signifificantly increased by SND (P<0.05). The mRNA expression of KCC2 was signifificantly decreased in SD rats (0.62±0.35 vs. 2.29±0.56; P=0.044), while SND showed a tendency to increase the mRNA of KCC2 in SD rats (P>0.05). By contrast, the mRNA expression of NKCC1 was signifificantly increased in the hippocampus of SD rats (6.58±1.54 vs. 2.82±0.32; P=0.011), while SND decreased the mRNA expression of NKCC1 (6.58±1.54 vs. 2.79±0.81; P=0.016). CONCLUSIONS Chinese medicine SND could alleviate mood disorder of SD rats by regulating cation-chloride cotransporters, such as NKCC1 and KCC2. These fifindings would have major implications in the mechanism of SND to relieve insomnia.
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Affiliation(s)
- Jing Liu
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Feng Li
- Beijing University of Chinese Medicine, Beijing, 100029, China.
| | - Xu-Dong Tang
- Xiyuan Hospital, Chinese Academy of Chinese Medical Science, Beijing, 100091, China
| | - Jie Ma
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Meng Mao
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Feng-Zhi Wu
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Shi-Jing Bai
- Beijng Science and Technology Publishing Co. Ltd., Beijing, 100035, China
| | - Yan-Yang Liu
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Chen-Xia Han
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Xin-Xue Li
- World Federation of Chinese Medicine Societies, Beijing, 100101, China
| | - Yan Liu
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Yue-Han Song
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Zhuo-Yun Wu
- Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Feng-Yun Wang
- Xiyuan Hospital, Chinese Academy of Chinese Medical Science, Beijing, 100091, China
| | - Nan Kang
- Xiyuan Hospital, Chinese Academy of Chinese Medical Science, Beijing, 100091, China
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Ip YK, Ching B, Hiong KC, Choo CYL, Boo MV, Wong WP, Chew SF. Light induces changes in activities of Na(+)/K(+)-ATPase, H(+)/K(+)-ATPase and glutamine synthetase in tissues involved directly or indirectly in light-enhanced calcification in the giant clam, Tridacna squamosa. Front Physiol 2015; 6:68. [PMID: 25798110 PMCID: PMC4351588 DOI: 10.3389/fphys.2015.00068] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 02/17/2015] [Indexed: 12/17/2022] Open
Abstract
The objective of this study was to determine the effects of 12 h of exposure to light, as compared with 12 h of exposure to darkness (control), on enzymatic activities of transporters involved in the transport of NH(+) 4 or H(+), and activities of enzymes involved in converting NH(+) 4 to glutamate/glutamine in inner mantle, outer mantle, and ctenidia of the giant clam, Tridacna squamosa. Exposure to light resulted in a significant increase in the effectiveness of NH(+) 4 in substitution for K(+) to activate Na(+)/K(+)-ATPase (NKA), manifested as a significant increase in the Na(+)/NH(+) 4-activated-NKA activity in the inner mantle. However, similar phenomena were not observed in the extensible outer mantle, which contained abundant symbiotic zooxanthellae. Hence, during light-enhanced calcification, H(+) released from CaCO3 deposition could react with NH3 to form NH(+) 4 in the extrapallial fluid, and NH(+) 4 could probably be transported into the shell-facing inner mantle epithelium through NKA. Light also induced an increase in the activity of glutamine synthetase, which converts NH(+) 4 and glutamate to glutamine, in the inner mantle. Taken together, these results explained observations reported elsewhere that light induced a significant increase in pH and a significant decrease in ammonia concentration in the extrapallial fluid, as well as a significant increase in the glutamine concentration in the inner mantle, of T. squamosa. Exposure of T. squamosa to light also led to a significant decrease in the N-ethylmaleimide (NEM)-sensitive-V-H(+)-ATPase (VATPase) in the inner mantle, and significant increases in the Na(+)/K(+)-activated-NKA, H(+)/NH(+) 4-activated-H(+)/K(+)-ATPase, and NEM-sensitive-VATPase activities in ctenidia, indicating that light-enhanced calcification might perturb Na(+) homeostasis and acid/base balance in the hemolymph, and might involve the active uptake of NH(+) 4 from the environment. This is the first report on light having direct enhancing effects on activities of certain transporters/enzymes related to light-enhanced calcification in the inner mantle and ctenidia of T. squamosa.
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Affiliation(s)
- Yuen K. Ip
- Department of Biological Sciences, National University of Singapore, SingaporeSingapore
- The Tropical Marine Science Institute, National University of Singapore, SingaporeSingapore
| | - Biyun Ching
- Department of Biological Sciences, National University of Singapore, SingaporeSingapore
- The Tropical Marine Science Institute, National University of Singapore, SingaporeSingapore
| | - Kum C. Hiong
- Department of Biological Sciences, National University of Singapore, SingaporeSingapore
- The Tropical Marine Science Institute, National University of Singapore, SingaporeSingapore
| | - Celine Y. L. Choo
- Department of Biological Sciences, National University of Singapore, SingaporeSingapore
- The Tropical Marine Science Institute, National University of Singapore, SingaporeSingapore
| | - Mel V. Boo
- Department of Biological Sciences, National University of Singapore, SingaporeSingapore
- The Tropical Marine Science Institute, National University of Singapore, SingaporeSingapore
| | - Wai P. Wong
- Department of Biological Sciences, National University of Singapore, SingaporeSingapore
| | - Shit F. Chew
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, SingaporeSingapore
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Urbina MA, Walsh PJ, Hill JV, Glover CN. Physiological and biochemical strategies for withstanding emersion in two galaxiid fishes. Comp Biochem Physiol A Mol Integr Physiol 2014; 176:49-58. [DOI: 10.1016/j.cbpa.2014.07.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 06/30/2014] [Accepted: 07/03/2014] [Indexed: 11/28/2022]
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Chew SF, Ip YK. Excretory nitrogen metabolism and defence against ammonia toxicity in air-breathing fishes. JOURNAL OF FISH BIOLOGY 2014; 84:603-38. [PMID: 24438022 DOI: 10.1111/jfb.12279] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
With the development of air-breathing capabilities, some fishes can emerge from water, make excursions onto land or even burrow into mud during droughts. Air-breathing fishes have modified gill morphology and morphometry and accessory breathing organs, which would tend to reduce branchial ammonia excretion. As ammonia is toxic, air-breathing fishes, especially amphibious ones, are equipped with various strategies to ameliorate ammonia toxicity during emersion or ammonia exposure. These strategies can be categorized into (1) enhancement of ammonia excretion and reduction of ammonia entry, (2) conversion of ammonia to a less toxic product for accumulation and subsequent excretion, (3) reduction of ammonia production and avoidance of ammonia accumulation and (4) tolerance of ammonia at cellular and tissue levels. Active ammonia excretion, operating in conjunction with lowering of ambient pH and reduction in branchial and cutaneous NH₃ permeability, is theoretically the most effective strategy to maintain low internal ammonia concentrations. NH₃ volatilization involves the alkalization of certain epithelial surfaces and requires mechanisms to prevent NH₃ back flux. Urea synthesis is an energy-intensive process and hence uncommon among air-breathing teleosts. Aestivating African lungfishes detoxify ammonia to urea and the accumulated urea is excreted following arousal. Reduction in ammonia production is achieved in some air-breathing fishes through suppression of amino acid catabolism and proteolysis, or through partial amino acid catabolism leading to alanine formation. Others can slow down ammonia accumulation through increased glutamine synthesis in the liver and muscle. Yet, some others develop high tolerance of ammonia at cellular and tissue levels, including tissues in the brain. In summary, the responses of air-breathing fishes to ameliorate ammonia toxicity are many and varied, determined by the behaviour of the species and the nature of the environment in which it lives.
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Affiliation(s)
- S F Chew
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616, Republic of Singapore
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Chen XL, Wee NLJE, Hiong KC, Ong JLY, Chng YR, Ching B, Wong WP, Chew SF, Ip YK. Properties and expression of Na+/K+-ATPase α-subunit isoforms in the brain of the swamp eel, Monopterus albus, which has unusually high brain ammonia tolerance. PLoS One 2013; 8:e84298. [PMID: 24391932 PMCID: PMC3877266 DOI: 10.1371/journal.pone.0084298] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 11/13/2013] [Indexed: 01/15/2023] Open
Abstract
The swamp eel, Monopterus albus, can survive in high concentrations of ammonia (>75 mmol l(-1)) and accumulate ammonia to high concentrations in its brain (4.5 µmol g(-1)). Na(+)/K(+)-ATPase (Nka) is an essential transporter in brain cells, and since NH4(+) can substitute for K(+) to activate Nka, we hypothesized that the brain of M. albus expressed multiple forms of Nka α-subunits, some of which might have high K(+) specificity. Thus, this study aimed to clone and sequence the nka α-subunits from the brain of M. albus, and to determine the effects of ammonia exposure on their mRNA expression and overall protein abundance. The effectiveness of NH4(+) to activate brain Nka from M. albus and Mus musculus was also examined by comparing their Na(+)/K(+)-ATPase and Na(+)/NH4(+)-ATPase activities over a range of K(+)/NH4(+) concentrations. The full length cDNA coding sequences of three nkaα (nkaα1, nkaα3a and nkaα3b) were identified in the brain of M. albus, but nkaα2 expression was undetectable. Exposure to 50 mmol l(-1) NH4Cl for 1 day or 6 days resulted in significant decreases in the mRNA expression of nkaα1, nkaα3a and nkaα3b. The overall Nka protein abundance also decreased significantly after 6 days of ammonia exposure. For M. albus, brain Na(+)/NH4(+)-ATPase activities were significantly lower than the Na(+)/K(+)-ATPase activities assayed at various NH4(+)/K(+) concentrations. Furthermore, the effectiveness of NH4(+) to activate Nka from the brain of M. albus was significantly lower than that from the brain of M. musculus, which is ammonia-sensitive. Hence, the (1) lack of nkaα2 expression, (2) high K(+) specificity of K(+) binding sites of Nkaα1, Nkaα3a and Nkaα3b, and (3) down-regulation of mRNA expression of all three nkaα isoforms and the overall Nka protein abundance in response to ammonia exposure might be some of the contributing factors to the high brain ammonia tolerance in M. albus.
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Affiliation(s)
- Xiu L. Chen
- Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore
| | - Nicklaus L. J. E. Wee
- Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore
| | - Kum C. Hiong
- Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore
| | - Jasmine L. Y. Ong
- Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore
| | - You R. Chng
- Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore
| | - Biyun Ching
- Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore
| | - Wai P. Wong
- Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore
| | - Shit F. Chew
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, Singapore, Republic of Singapore
| | - Yuen K. Ip
- Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore
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