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Pinki F, Costello DA, Stewart G. Regional investigation of UT-B urea transporters in the rat brain. Biochem Biophys Rep 2023; 36:101563. [PMID: 37929290 PMCID: PMC10624589 DOI: 10.1016/j.bbrep.2023.101563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 11/07/2023] Open
Abstract
Recent studies have reported increased levels of urea in the aging brain and various neurological disorders. Additionally, these diseased tissues also have increased expression of the UT-B transporter that regulates urea transport in the brain. However, little is known regarding the actual UT-B protein distribution across the brain in either normal or diseased states. This current study investigated UT-B protein abundance across three regions of the rat brain - anterior, posterior and cerebellum. Endpoint RT-PCR experiments showed that there were no regional differences in UT-B RNA expression (NS, N = 3, ANOVA), whilst Western blotting confirmed no difference in the abundance of a 35 kDa UT-B protein (NS, N = 3-4, ANOVA). In contrast, there was a significant variation in a non-UT-B 100 kDa protein (P < 0.001, N = 3-4, ANOVA), which was also detected by anti-UT-B antibodies. Using the C6 rat astrocyte cell line, Western blot analysis showed that 48-h incubation in either 5 mM or 10 mM significantly increased a 30-45 kDa UT-B protein signal (P < 0.05, N = 3, ANOVA). Furthermore, investigation of compartmentalized C6 protein samples showed the 30-45 kDa signal in the membrane fraction, whilst the 100 kDa non-UT-B signal was predominantly in the cytosolic fraction. Finally, immunolocalization studies gave surprisingly weak detection of rat UT-B, except for strong staining of red blood cells in the cerebellum. In conclusion, this study confirmed that RNA expression and protein abundance of UT-B were equal across all regions of the rat brain, suggesting that urea levels were also similar. However, it also highlighted some of the technical challenges of studying urea transporters at the protein level.
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Affiliation(s)
- Farhana Pinki
- UCD School of Biology and Environmental Science, University College Dublin, Dublin 4, Ireland
| | - Derek A Costello
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
- UCD Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Gavin Stewart
- UCD School of Biology and Environmental Science, University College Dublin, Dublin 4, Ireland
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You X, Rani A, Özcan E, Lyu Y, Sela DA. Bifidobacterium longum subsp. infantis utilizes human milk urea to recycle nitrogen within the infant gut microbiome. Gut Microbes 2023; 15:2192546. [PMID: 36967532 PMCID: PMC10054289 DOI: 10.1080/19490976.2023.2192546] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
Human milk guides the structure and function of microbial commensal communities that colonize the nursing infant gut. Indigestible molecules dissolved in human milk establish a microbiome often dominated by bifidobacteria capable of utilizing these substrates. Interestingly, urea accounts for ~15% of total human milk nitrogen, representing a potential reservoir for microbiota that may be salvaged for critical metabolic operations during lactation and neonatal development. Accordingly, B. infantis strains are competent for urea nitrogen utilization, constituting a previously hypothetical phenotype in commensal bacteria hosted by humans. Urease gene expression, downstream nitrogen metabolic pathways, and enzymatic activity are induced during urea utilization to yield elevated ammonia concentrations. Moreover, biosynthetic networks relevant to infant nutrition and development are transcriptionally responsive to urea utilization including branched chain and other essential amino acids. Importantly, isotopically labeled urea nitrogen is broadly distributed throughout the expressed B. infantis proteome. This incisively demonstrates that the previously inaccessible urea nitrogen is incorporated into microbial products available for infant host utilization. In aggregate, B. infantis possesses the requisite phenotypic foundation to participate in human milk urea nitrogen recycling within its infant host and thus may be a key contributor to nitrogen homeostasis early in life.
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Affiliation(s)
- Xiaomeng You
- Department of Food Science, University of Massachusetts, Amherst, MA, USA
| | - Asha Rani
- Department of Food Science, University of Massachusetts, Amherst, MA, USA
| | - Ezgi Özcan
- Department of Food Science, University of Massachusetts, Amherst, MA, USA
| | - Yang Lyu
- Department of Food Science, University of Massachusetts, Amherst, MA, USA
| | - David A Sela
- Department of Food Science, University of Massachusetts, Amherst, MA, USA
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA
- Department of Nutrition, University of Massachusetts, Amherst, MA, USA
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, USA
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Zhu Q, Zhan D, Yang Y, Chong Y, Xue H, Zhu P. LINC00173 Promotes Wilms’ Tumor Progression Through MGAT1-mediated MUC3A N-glycosylation. Cell Cycle 2022; 21:1795-1810. [PMID: 35491865 DOI: 10.1080/15384101.2022.2070399] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- Qingliang Zhu
- Department of Urology Surgery, Jiangdu People’s Hospital of Yangzhou, Yangzhou, 225200, Jiangsu, China
| | - Deming Zhan
- Department of Urology Surgery, Jiangdu People’s Hospital of Yangzhou, Yangzhou, 225200, Jiangsu, China
| | - Yongguo Yang
- Department of Pathology, Jiangdu People’s Hospital of Yangzhou, Yangzhou, 225200, Jiangsu, China
| | - Yankun Chong
- Department of Urology Surgery, Jiangdu People’s Hospital of Yangzhou, Yangzhou, 225200, Jiangsu, China
| | - Haoliang Xue
- Department of Urology Surgery, Jiangdu People’s Hospital of Yangzhou, Yangzhou, 225200, Jiangsu, China
| | - Peng Zhu
- Department of Urology Surgery, Jiangdu People’s Hospital of Yangzhou, Yangzhou, 225200, Jiangsu, China
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Hailemariam S, Zhao S, He Y, Wang J. Urea transport and hydrolysis in the rumen: A review. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2021; 7:989-996. [PMID: 34738029 PMCID: PMC8529027 DOI: 10.1016/j.aninu.2021.07.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 07/02/2021] [Accepted: 07/08/2021] [Indexed: 11/29/2022]
Abstract
Inefficient dietary nitrogen (N) conversion to microbial proteins, and the subsequent use by ruminants, is a major research focus across different fields. Excess bacterial ammonia (NH3) produced due to degradation or hydrolyses of N containing compounds, such as urea, leads to an inefficiency in a host's ability to utilize nitrogen. Urea is a non-protein N containing compound used by ruminants as an ammonia source, obtained from feed and endogenous sources. It is hydrolyzed by ureases from rumen bacteria to produce NH3 which is used for microbial protein synthesis. However, lack of information exists regarding urea hydrolysis in ruminal bacteria, and how urea gets to hydrolysis sites. Therefore, this review describes research on sites of urea hydrolysis, urea transport routes towards these sites, the role and structure of urea transporters in rumen epithelium and bacteria, the composition of ruminal ureolytic bacteria, mechanisms behind urea hydrolysis by bacterial ureases, and factors influencing urea hydrolysis. This review explores the current knowledge on the structure and physiological role of urea transport and ureolytic bacteria, for the regulation of urea hydrolysis and recycling in ruminants. Lastly, underlying mechanisms of urea transportation in rumen bacteria and their physiological importance are currently unknown, and therefore future research should be directed to this subject.
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Affiliation(s)
- Samson Hailemariam
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
- Dilla University, College of Agriculture and Natural Resource, Dilla P. O. Box 419, Ethiopia
| | - Shengguo Zhao
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yue He
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jiaqi Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
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Decaux G, Gankam Kengne F. Hypertonic saline, isotonic saline, water restriction, long loops diuretics, urea or vaptans to treat hyponatremia. Expert Rev Endocrinol Metab 2020; 15:195-214. [PMID: 32401559 DOI: 10.1080/17446651.2020.1755259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/09/2020] [Indexed: 01/08/2023]
Abstract
Introduction: Hyponatremia is the most common fluid and electrolyte abnormality. It is associated with much higher morbidity and mortality rates than found in non hyponatremic patients.Areas covered: When the physician is faced to a hyponatremic patient he first has to confirm that hyponatremia is associated with hypoosmolality. Then he must answer to a series of questions: What is its origin? Is it acute or chronic? Which treatment is the most appropriate? We will discuss the various options for the treatment of hypotonic hyponatremia. For a better comprehensive approach of the treatment we will also discuss some pathophysiological data. The use of urea in euvolemic and hypervolemic hyponatremia will be particularly discussed. Literature was reviewed from Jan 1970 to Dec 2019.Expert opinion: Prospective studies showing the benefit in decreasing morbidity by increasing SNa in patients with chronic hyponatremia should be done. These studies should also compare the efficacy and side effects of urea therapy compare to vaptans.
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Affiliation(s)
- Guy Decaux
- Department of Internal Medicine, Erasmus University Hospital, ULB, Brussels, Belgium
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Yu L, Liu T, Fu S, Li L, Meng X, Su X, Xie Z, Ren J, Meng Y, Lv X, Du Y. Physiological functions of urea transporter B. Pflugers Arch 2019; 471:1359-1368. [PMID: 31734718 PMCID: PMC6882768 DOI: 10.1007/s00424-019-02323-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 10/16/2019] [Accepted: 10/17/2019] [Indexed: 11/04/2022]
Abstract
Urea transporters (UTs) are membrane proteins in the urea transporter protein A (UT-A) and urea transporter protein B (UT-B) families. UT-B is mainly expressed in endothelial cell membrane of the renal medulla and in other tissues, including the brain, heart, pancreas, colon, bladder, bone marrow, and cochlea. UT-B is responsible for the maintenance of urea concentration, male reproductive function, blood pressure, bone metabolism, and brain astrocyte and cardiac functions. Its deficiency and dysfunction contribute to the pathogenesis of many diseases. Actually, UT-B deficiency increases the sensitivity of bladder epithelial cells to apoptosis triggers in mice and UT-B-null mice develop II-III atrioventricular block and depression. The expression of UT-B in the rumen of cow and sheep may participate in digestive function. However, there is no systemic review to discuss the UT-B functions. Here, we update research approaches to understanding the functions of UT-B.
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Affiliation(s)
- Lanying Yu
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Tiantian Liu
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Shuang Fu
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Li Li
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Xiaoping Meng
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Xin Su
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Zhanfeng Xie
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Jiayan Ren
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China
| | - Yan Meng
- Department of Pathophysiology, College of Basic Medicine, Jilin University, Changchun, 130021, Jilin, People's Republic of China.
| | - Xuejiao Lv
- Department of Respiratory Medicine, the Second Affiliated Hospital of Jilin University, Changchun, 130041, Jilin, People's Republic of China.
| | - Yanwei Du
- Changchun University of Chinese Medicine, Changchun, 130117, People's Republic of China.
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