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Poulsen SB, Murali SK, Thomas L, Assmus A, Rosenbæk LL, Nielsen R, Dimke H, Rieg T, Fenton RA. Genetic deletion of the kidney sodium/proton exchanger-3 (NHE3) does not alter calcium and phosphate balance due to compensatory responses. Kidney Int 2024:S0085-2538(24)00533-7. [PMID: 39089578 DOI: 10.1016/j.kint.2024.07.013] [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: 07/05/2022] [Revised: 06/10/2024] [Accepted: 07/02/2024] [Indexed: 08/04/2024]
Abstract
The sodium/proton exchanger-3 (NHE3) plays a major role in acid-base and extracellular volume regulation and is also implicated in calcium homeostasis. As calcium and phosphate balances are closely linked, we hypothesized that there was a functional link between kidney NHE3 activity, calcium, and phosphate balance. Therefore, we examined calcium and phosphate homeostasis in kidney tubule-specific NHE3 knockout mice (NHE3loxloxPax8 mice). Compared to controls, these knockout mice were normocalcemic with no significant difference in urinary calcium excretion or parathyroid hormone levels. Thiazide-induced hypocalciuria was less pronounced in the knockout mice, in line with impaired proximal tubule calcium transport. Knockout mice had greater furosemide-induced calciuresis and distal tubule calcium transport pathways were enhanced. Despite lower levels of the sodium/phosphate cotransporters (NaPi)-2a and -2c, knockout mice had normal plasma phosphate, sodium-dependent 32Phosphate uptake in proximal tubule membrane vesicles and urinary phosphate excretion. Intestinal phosphate uptake was unchanged. Low dietary phosphate reduced parathyroid hormone levels and increased NaPi-2a and -2c abundances in both genotypes, but NaPi-2c levels remained lower in the knockout mice. Gene expression profiling suggested proximal tubule remodeling in the knockout mice. Acutely, indirect NHE3 inhibition using the SGLT2 inhibitor empagliflozin did not affect urinary calcium and phosphate excretion. No differences in femoral bone density or architecture were detectable in the knockout mice. Thus, a role for kidney NHE3 in calcium homeostasis can be unraveled by diuretics, but NHE3 deletion in the kidneys has no major effects on overall calcium and phosphate homeostasis due, at least in part, to compensating mechanisms.
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Affiliation(s)
- Søren B Poulsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Sathish K Murali
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Linto Thomas
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida, USA
| | - Adrienne Assmus
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Lena L Rosenbæk
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Rikke Nielsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark; Department of Nephrology, Odense University Hospital, Odense, Denmark
| | - Timo Rieg
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida, USA; James A. Haley Veterans' Hospital, Tampa, Florida, USA.
| | - Robert A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
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2
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Xu FZ, Meng FR, Li WJ, Xu L, Zhang H, Zhang YB, Fan XY. Predictive value of serum magnesium levels for prognosis in patients with non-small cell lung cancer undergoing EGFR-TKI therapy. Open Life Sci 2024; 19:20220923. [PMID: 39071492 PMCID: PMC11282910 DOI: 10.1515/biol-2022-0923] [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: 02/25/2024] [Revised: 05/29/2024] [Accepted: 06/17/2024] [Indexed: 07/30/2024] Open
Abstract
The aim of this study is to assess the impact of serum magnesium (Mg) levels on prognostic outcomes in patients with non-small cell lung cancer (NSCLC) undergoing treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI). A cohort comprising 91 patients with NSCLC with epidermal growth factor receptor mutations received EGFR-TKI therapy. Assessments of liver and kidney function and electrolyte levels were conducted before treatment initiation and after completing two cycles of EGFR-TKI therapy. Data on variables such as age, gender, presence of distant metastasis, smoking history, other therapeutic interventions, and the specific TKI used were collected for analysis. Cox regression analysis revealed that patients with higher Mg levels prior to EGFR-TKI therapy had significantly longer progression-free survival (PFS) and overall survival (OS). Elevated Mg levels remained predictive of PFS and OS after two cycles of EGFR-TKI therapy. Multiple regression analysis confirmed these findings. Additionally, it was observed that smokers might represent a unique population, demonstrating a correlation between OS and Mg levels. Our findings indicate that serum Mg level is a prognostic factor in patients with NSCLC undergoing EGFR-TKI therapy. This may provide new insights into the underlying mechanisms of EGFR-TKI therapy related to electrolyte balance.
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Affiliation(s)
- Fang-Zhou Xu
- Department of Geriatric Respiratory and Critical Care Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, 230032, Anhui, China
- Anhui Geriatric Institute, Hefei, 230001, Anhui, China
| | - Fu-Rong Meng
- Department of Geriatric Respiratory and Critical Care Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, 230032, Anhui, China
- Anhui Geriatric Institute, Hefei, 230001, Anhui, China
| | - Wan-Jing Li
- Department of Geriatric Respiratory and Critical Care Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, 230032, Anhui, China
- Anhui Geriatric Institute, Hefei, 230001, Anhui, China
| | - Lu Xu
- Department of Geriatric Respiratory and Critical Care Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, 230032, Anhui, China
| | - Hao Zhang
- Department of Geriatric Respiratory and Critical Care Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, 230032, Anhui, China
| | - Yan-Bei Zhang
- Department of Geriatric Respiratory and Critical Care Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, 230032, Anhui, China
| | - Xiao-Yun Fan
- Anhui Geriatric Institute, Hefei, 230001, Anhui, China
- Department of Geriatric Respiratory and Critical Care Medicine, The First Affiliated Hospital of Anhui Medical University, No. 218 of JiXi Road, ShuShan District, Hefei, 230032, Anhui, China
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3
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Marneros AG. Aplasia Cutis Congenita Pathomechanisms Reveal Key Regulators of Skin and Skin Appendage Morphogenesis. J Invest Dermatol 2024:S0022-202X(24)01730-5. [PMID: 39023472 DOI: 10.1016/j.jid.2024.05.014] [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: 03/29/2024] [Revised: 05/03/2024] [Accepted: 05/18/2024] [Indexed: 07/20/2024]
Abstract
Aplasia cutis congenita (ACC) manifests at birth as a defect of the scalp skin. New findings answer 2 longstanding questions: why ACC forms and why it affects mainly the midline scalp skin. Dominant-negative mutations in the genes KCTD1 or KCTD15 cause ACC owing to loss of function of KCTD1/KCTD15 complexes in cranial neural crest cells (NCCs), which normally form midline cranial suture mesenchymal cells that express keratinocyte growth factors. Loss of KCTD1/KCTD15 function in NCCs impairs the formation of normal midline cranial sutures and, consequently, the overlying skin, resulting in ACC. Moreover, KCTD1/KCTD15 complexes in keratinocytes regulate skin appendage morphogenesis.
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Affiliation(s)
- Alexander G Marneros
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.
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4
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Raymundo JR, Zhang H, Smaldone G, Zhu W, Daly KE, Glennon BJ, Pecoraro G, Salvatore M, Devine WA, Lo CW, Vitagliano L, Marneros AG. KCTD1/KCTD15 complexes control ectodermal and neural crest cell functions, and their impairment causes aplasia cutis. J Clin Invest 2023; 134:e174138. [PMID: 38113115 PMCID: PMC10866662 DOI: 10.1172/jci174138] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 12/13/2023] [Indexed: 12/21/2023] Open
Abstract
Aplasia cutis congenita (ACC) is a congenital epidermal defect of the midline scalp and has been proposed to be due to a primary keratinocyte abnormality. Why it forms mainly at this anatomic site has remained a long-standing enigma. KCTD1 mutations cause ACC, ectodermal abnormalities, and kidney fibrosis, whereas KCTD15 mutations cause ACC and cardiac outflow tract abnormalities. Here, we found that KCTD1 and KCTD15 can form multimeric complexes and can compensate for each other's loss and that disease mutations are dominant negative, resulting in lack of KCTD1/KCTD15 function. We demonstrated that KCTD15 is critical for cardiac outflow tract development, whereas KCTD1 regulates distal nephron function. Combined inactivation of KCTD1/KCTD15 in keratinocytes resulted in abnormal skin appendages but not in ACC. Instead, KCTD1/KCTD15 inactivation in neural crest cells resulted in ACC linked to midline skull defects, demonstrating that ACC is not caused by a primary defect in keratinocytes but is a secondary consequence of impaired cranial neural crest cells, giving rise to midline cranial suture cells that express keratinocyte-promoting growth factors. Our findings explain the clinical observations in patients with KCTD1 versus KCTD15 mutations, establish KCTD1/KCTD15 complexes as critical regulators of ectodermal and neural crest cell functions, and define ACC as a neurocristopathy.
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Affiliation(s)
- Jackelyn R. Raymundo
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Hui Zhang
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | | | - Wenjuan Zhu
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, USA
| | - Kathleen E. Daly
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Benjamin J. Glennon
- Developmental Biology Department, John G. Rangos Sr. Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | | | | - William A. Devine
- Developmental Biology Department, John G. Rangos Sr. Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Cecilia W. Lo
- Developmental Biology Department, John G. Rangos Sr. Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Luigi Vitagliano
- Institute of Biostructures and Bioimaging, Consiglio Nazionale delle Ricerche, Naples, Italy
| | - Alexander G. Marneros
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
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Tang H, Xu C, Zhang P, Luo T, Huang Y, Yang X. A profile of SGLT-2 inhibitors in hyponatremia: The evidence to date. Eur J Pharm Sci 2023; 184:106415. [PMID: 36870579 DOI: 10.1016/j.ejps.2023.106415] [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: 11/27/2022] [Revised: 02/14/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023]
Abstract
Hyponatremia is the most common electrolyte disorder in clinical practice, which may lead to life-threatening complications. Several lines of evidence suggest that hyponatremia is associated not only with significant increases in length of stay, cost, and financial burden, but also with increased morbidity and mortality. Hyponatremia is also considered to be a negative prognostic factor in patients with heart failure and cancer. Although multiple therapeutic methods are available for treating hyponatremia, most have some limitations, such as poor compliance, rapid correction of serum Na+, other negative side effects and high cost. Given these limitations, identifying novel therapies for hyponatremia is essential. Recent clinical studies have shown that SGLT-2 inhibitors (SGLT 2i) significantly increased serum Na+ levels and were well tolerated by patients who underwent this treatment. Therefore, oral administration of SGLT 2i appears to be an effective treatment for hyponatremia. This article will briefly review the etiology of hyponatremia and integrated control of sodium within the kidney, current therapies for hyponatremia, potential mechanisms and efficacy of SGLT 2i for hyponatremia, and the benefits in cardiovascular, cancer, and kidney disease by regulating sodium and water balance.
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Affiliation(s)
- Hui Tang
- Department of Pharmacy, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, China; School of Pharmacy, Southwest Medical University, Luzhou 646000, China
| | - Changjing Xu
- Department of Pharmacy, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, China
| | - Piao Zhang
- Department of Pharmacy, Ya 'an People's Hospital, Ya 'an, Sichuan 646000, China
| | - Taimin Luo
- Department of pharmacy, Chengdu Seventh People's Hospital, Chengdu, Sichuan 610000, China
| | - Yilan Huang
- Department of Pharmacy, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, China; School of Pharmacy, Southwest Medical University, Luzhou 646000, China.
| | - Xuping Yang
- Department of Pharmacy, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, China; School of Pharmacy, Southwest Medical University, Luzhou 646000, China.
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Smaldone G, Pecoraro G, Pane K, Franzese M, Ruggiero A, Vitagliano L, Salvatore M. The Oncosuppressive Properties of KCTD1: Its Role in Cell Growth and Mobility. BIOLOGY 2023; 12:biology12030481. [PMID: 36979172 PMCID: PMC10045846 DOI: 10.3390/biology12030481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023]
Abstract
The KCTD protein family is traditionally regarded as proteins that play key roles in neurological physiopathology. However, new studies are increasingly demonstrating their involvement in many other biological processes, including cancers. This is particularly evident for KCTD proteins not involved in protein ubiquitination and degradation, such as KCTD1. We explored the role of KCTD1 in colorectal cancer by knocking down this protein in the human colon adenocarcinoma cell line, SW480. We re-assessed its ability to downregulate β-catenin, a central actor in the WNT/β-catenin signalling pathway. Interestingly, opposite effects are observed when the protein is upregulated in CACO2 colorectal cancer cells. Moreover, interrogation of the TCGA database indicates that KCTD1 downregulation is associated with β-catenin overexpression in colorectal cancer patients. Indeed, knocking down KCTD1 in SW480 cells led to a significant increase in their motility and stemness, two important tumorigenesis traits, suggesting an oncosuppressor role for KCTD1. It is worth noting that similar effects are induced on colorectal cancer cells by the misregulation of KCTD12, a protein that is distantly related to KCTD1. The presented results further expand the spectrum of KCTD1 involvement in apparently unrelated physiopathological processes. The similar effects produced on colorectal cancer cell lines by KCTD1 and KCTD12 suggest novel, previously unreported analogous activities among members of the KCTD protein family.
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Affiliation(s)
| | | | - Katia Pane
- IRCCS SYNLAB SDN, Via E. Gianturco 113, 80143 Naples, Italy
| | | | - Alessia Ruggiero
- Institute of Biostructures and Bioimaging, C.N.R., 80134 Napoli, Italy
| | - Luigi Vitagliano
- Institute of Biostructures and Bioimaging, C.N.R., 80134 Napoli, Italy
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7
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Abstract
Mg2+ is essential for many cellular and physiological processes, including muscle contraction, neuronal activity, and metabolism. Consequently, the blood Mg2+ concentration is tightly regulated by balanced intestinal Mg2+ absorption, renal Mg2+ excretion, and Mg2+ storage in bone and soft tissues. In recent years, the development of novel transgenic animal models and identification of Mendelian disorders has advanced our current insight in the molecular mechanisms of Mg2+ reabsorption in the kidney. In the proximal tubule, Mg2+ reabsorption is dependent on paracellular permeability by claudin-2/12. In the thick ascending limb of Henle's loop, the claudin-16/19 complex provides a cation-selective pore for paracellular Mg2+ reabsorption. The paracellular Mg2+ reabsorption in this segment is regulated by the Ca2+-sensing receptor, parathyroid hormone, and mechanistic target of rapamycin (mTOR) signaling. In the distal convoluted tubule, the fine tuning of Mg2+ reabsorption takes place by transcellular Mg2+ reabsorption via transient receptor potential melastatin-like types 6 and 7 (TRPM6/TRPM7) divalent cation channels. Activity of TRPM6/TRPM7 is dependent on hormonal regulation, metabolic activity, and interacting proteins. Basolateral Mg2+ extrusion is still poorly understood but is probably dependent on the Na+ gradient. Cyclin M2 and SLC41A3 are the main candidates to act as Na+/Mg2+ exchangers. Consequently, disturbances of basolateral Na+/K+ transport indirectly result in impaired renal Mg2+ reabsorption in the distal convoluted tubule. Altogether, this review aims to provide an overview of the molecular mechanisms of Mg2+ reabsorption in the kidney, specifically focusing on transgenic mouse models and human hereditary diseases.
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Affiliation(s)
- Jeroen H F de Baaij
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
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Wang D, Trevillian P, May S, Diakumis P, Wang Y, Colville D, Bahlo M, Greferath U, Fletcher E, Young B, Mack HG, Savige J. KCTD1 and Scalp-Ear-Nipple ('Finlay-Marks') syndrome may be associated with myopia and Thin basement membrane nephropathy through an effect on the collagen IV α3 and α4 chains. Ophthalmic Genet 2023; 44:19-27. [PMID: 36579937 DOI: 10.1080/13816810.2022.2144900] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Scalp-Ear-Nipple syndrome is caused by pathogenic KCTD1 variants and characterised by a scalp defect, prominent ears, and rudimentary breasts. We describe here further clinical associations in the eye and kidney. METHODS Fifteen affected members from two unrelated families with p.(Ala30Glu) or p.(Pro31Leu) in KCTD1 were examined for ocular and renal abnormalities. The relevant proteins were studied in the eye and kidney, and the mutation consequences determined from mouse knockout models. RESULTS Five males and 10 females with a median age of 40 years (range 1-70) with pathogenic variants p.(Ala30Glu) (n = 12) or p.(Pro31Leu) (n = 3) in KCTD1 were studied. Of the 6 who underwent detailed ophthalmic examination, 5 (83%) had low myopic astigmatism, the mean spherical equivalent of 10 eyes was 2.38D, and one (17%) had hypermetropic astigmatism. One female had a divergent strabismus.Five individuals had renal cysts (5/15, 33%), with renal biopsy in one demonstrating a thinned glomerular basement membrane identical to that seen in Thin basement membrane nephropathy (AD Alport syndrome).In the eye, KCTD1 and its downstream targets, TFAP2, and the collagen IV α3 and α4 chains localised to the cornea and near the retinal amacrine cells. In the kidney, all these proteins except TFAP2 were expressed in the podocytes and distal tubules. TFAP2B and COL4A4 knockout mice also had kidney cysts, and COL4A3 and COL4A4 knockout mice had myopia. CONCLUSION Individuals with a pathogenic KCTD1 variant may have low myopic astigmatism and represent a further rare genetic cause for a thinned glomerular basement membrane.
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Affiliation(s)
- Dongmao Wang
- Department of Medicine (Northern Health and Melbourne Health), University of Melbourne, Melbourne, Australia
| | - Paul Trevillian
- Department of Nephrology, John Hunter Hospital, Newcastle, Australia
| | - Stephen May
- Renal Unit, Tamworth Hospital, Tamworth, Australia
| | - Peter Diakumis
- Department of Bioinformatics, Walter and Eliza Hall Institute, Parkville, Australia
| | - Yanyan Wang
- Department of Medicine (Northern Health and Melbourne Health), University of Melbourne, Melbourne, Australia
| | - Deb Colville
- Department of Medicine (Northern Health and Melbourne Health), University of Melbourne, Melbourne, Australia
| | - Melanie Bahlo
- Department of Bioinformatics, Walter and Eliza Hall Institute, Parkville, Australia
| | - Una Greferath
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia
| | - Erica Fletcher
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia
| | - Barbara Young
- Department of Pathology John Hunter Hospital, Newcastle, Australia
| | - Heather G Mack
- Department of Ophthalmology, Royal Victorian Eye and Ear Hospital, University of Melbourne, East Melbourne, Australia
| | - Judy Savige
- Department of Medicine (Northern Health and Melbourne Health), University of Melbourne, Melbourne, Australia
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Li H, Dixon EE, Wu H, Humphreys BD. Comprehensive single-cell transcriptional profiling defines shared and unique epithelial injury responses during kidney fibrosis. Cell Metab 2022; 34:1977-1998.e9. [PMID: 36265491 PMCID: PMC9742301 DOI: 10.1016/j.cmet.2022.09.026] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 07/19/2022] [Accepted: 09/28/2022] [Indexed: 01/12/2023]
Abstract
The underlying cellular events driving kidney fibrogenesis and metabolic dysfunction are incompletely understood. Here, we employed single-cell combinatorial indexing RNA sequencing to analyze 24 mouse kidneys from two fibrosis models. We profiled 309,666 cells in one experiment, representing 50 cell types/states encompassing epithelial, endothelial, immune, and stromal populations. Single-cell analysis identified diverse injury states of the proximal tubule, including two distinct early-phase populations with dysregulated lipid and amino acid metabolism, respectively. Lipid metabolism was defective in the chronic phase but was transiently activated in the very early stages of ischemia-induced injury, where we discovered increased lipid deposition and increased fatty acid β-oxidation. Perilipin 2 was identified as a surface marker of intracellular lipid droplets, and its knockdown in vitro disrupted cell energy state maintenance during lipid accumulation. Surveying epithelial cells across nephron segments identified shared and unique injury responses. Stromal cells exhibited high heterogeneity and contributed to fibrogenesis by epithelial-stromal crosstalk.
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Affiliation(s)
- Haikuo Li
- Division of Nephrology, Department of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Eryn E Dixon
- Division of Nephrology, Department of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Haojia Wu
- Division of Nephrology, Department of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Benjamin D Humphreys
- Division of Nephrology, Department of Medicine, Washington University in St. Louis, St. Louis, MO, USA; Department of Developmental Biology, Washington University in St. Louis, St. Louis, MO, USA.
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Carboxymethylation of Desmodium styracifolium Polysaccharide and Its Repair Effect on Damaged HK-2 Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:2082263. [PMID: 35993017 PMCID: PMC9391130 DOI: 10.1155/2022/2082263] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 06/29/2022] [Accepted: 07/23/2022] [Indexed: 11/17/2022]
Abstract
Objective Desmodium styracifolium is the best traditional medicine for treating kidney calculi in China. This study is aimed at increasing the carboxyl (-COOH) content of D. styracifolium polysaccharide (DSP0) and further increasing its antistone activity. Methods DSP0 was carboxymethylated with chloroacetic acid at varying degrees. Then, oxalate-damaged HK-2 cells were repaired with modified polysaccharide, and the changes in biochemical indices before and after repair were detected. Results Three modified polysaccharides with 7.45% (CDSP1), 12.2% (CDSP2), and 17.7% (CDSP3) -COOH are obtained. Compared with DSP0 (-COOH content = 1.17%), CDSPs have stronger antioxidant activity in vitro and can improve the vitality of damaged HK-2 cells. CDSPs repair the cell morphology and cytoskeleton, increase the cell healing ability, reduce reactive oxygen species and nitric oxide levels, increase mitochondrial membrane potential, limit autophagy level to a low level, reduce the eversion of phosphatidylserine in the cell membrane, weaken the inhibition of oxalate on DNA synthesis, restore cell cycle to normal state, promote cell proliferation, and reduce apoptosis/necrosis. Conclusion The carboxymethylation modification of DSP0 can improve its antioxidant activity and enhance its ability to repair damaged HK-2 cells. Among them, CDSP2 with medium -COOH content has the highest activity of repairing cells, whereas CDSP3 with the highest -COOH content has the highest antioxidant activity. This difference may be related to the active environment of polysaccharide and conformation of the polysaccharide and cell signal pathway. This result suggests that Desmodium styracifolium polysaccharide with increased -COOH content may have improved potential treatment and prevention of kidney calculi.
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11
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Lamontagne JO, Zhang H, Zeid AM, Strittmatter K, Rocha AD, Williams T, Zhang S, Marneros AG. Transcription factors AP-2α and AP-2β regulate distinct segments of the distal nephron in the mammalian kidney. Nat Commun 2022; 13:2226. [PMID: 35468900 PMCID: PMC9038906 DOI: 10.1038/s41467-022-29644-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 03/22/2022] [Indexed: 12/13/2022] Open
Abstract
Transcription factors AP-2α and AP-2β have been suggested to regulate the differentiation of nephron precursor populations towards distal nephron segments. Here, we show that in the adult mammalian kidney AP-2α is found in medullary collecting ducts, whereas AP-2β is found in distal nephron segments except for medullary collecting ducts. Inactivation of AP-2α in nephron progenitor cells does not affect mammalian nephrogenesis, whereas its inactivation in collecting ducts leads to defects in medullary collecting ducts in the adult. Heterozygosity for AP-2β in nephron progenitor cells leads to progressive distal convoluted tubule abnormalities and β-catenin/mTOR hyperactivation that is associated with renal fibrosis and cysts. Complete loss of AP-2β in nephron progenitor cells caused an absence of distal convoluted tubules, renal cysts, and fibrosis with β-catenin/mTOR hyperactivation, and early postnatal death. Thus, AP-2α and AP-2β have non-redundant distinct spatiotemporal functions in separate segments of the distal nephron in the mammalian kidney. How the distal nephron is patterned during kidney development has been difficult to study. Here they show that AP-2β is required for the formation and postnatal function of distal convoluted tubules, whereas AP-2α has a role in maintaining the structure of medullary collecting ducts.
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Affiliation(s)
- Joseph O Lamontagne
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Hui Zhang
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Alia M Zeid
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Karin Strittmatter
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Alicia D Rocha
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Trevor Williams
- Department of Craniofacial Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Sheryl Zhang
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Alexander G Marneros
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA.
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12
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Zeid AM, Lamontagne JO, Zhang H, Marneros AG. Epidermal growth factor deficiency predisposes to progressive renal disease. FASEB J 2022; 36:e22286. [PMID: 35442545 DOI: 10.1096/fj.202101837r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 02/05/2022] [Accepted: 03/17/2022] [Indexed: 01/22/2023]
Abstract
Epidermal growth factor (EGF) is produced in the kidney by thick ascending limbs of the loop of Henle and by distal convoluted tubules (DCTs). Reduced urinary EGF levels have been associated with chronic kidney disease but it is not known whether physiological levels of EGF protect the kidney from progressive renal disease. Here, we show that EGF-deficient mice on a mixed genetic background had increased urinary microalbumin, and a subset of these mice developed severe progressive renal disease with azotemia that was not seen in WT or TGFα-deficient littermates with this mixed genetic background. These azotemic EGF-deficient mice developed crescentic glomerulonephritis linked to HB-EGF/EGFR hyperactivation in glomeruli, as well as attenuation of the proximal tubule brush border, distal convoluted tubule (DCT) dilatation, and kidney fibrosis associated with renal β-catenin/mTOR hyperactivation. The observation of these severe renal pathologies only in a subset of EGF-deficient mice suggests that independent segregation of strain-specific modifier alleles contributes to the severity of the renal abnormalities that only manifest when EGF is lacking. These findings link the lack of EGF to renal pathologies in the adult mammalian kidney, in support of a role of physiological levels of EGF for maintaining the function of glomeruli, proximal tubules, and DCTs. These observations suggest that diminished EGF levels predispose kidneys to progressive renal disease.
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Affiliation(s)
- Alia M Zeid
- Department of Dermatology, Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Joseph O Lamontagne
- Department of Dermatology, Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Hui Zhang
- Department of Dermatology, Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Alexander G Marneros
- Department of Dermatology, Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
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Peride I, Tiglis M, Neagu TP, Niculae A, Checherita IA. Magnesium—A More Important Role in CKD–MBD than We Thought. Diagnostics (Basel) 2022; 12:diagnostics12040880. [PMID: 35453928 PMCID: PMC9031465 DOI: 10.3390/diagnostics12040880] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/13/2022] [Accepted: 03/30/2022] [Indexed: 12/17/2022] Open
Abstract
Chronic kidney disease (CKD) is associated with different complications, including chronic kidney disease–mineral and bone disorder (CKD–MBD), which represents a systemic disorder that involves the presence of different mineral or bone structure abnormalities (i.e., modification of bone turnover, strength, volume, etc.), including even vascular calcification development. Even if, over the years, different pathophysiological theories have been developed to explain the onset and progression of CKD–MBD, the influence and importance of serum magnesium level on the evolution of CKD have only recently been highlighted. So far, data are inconclusive and conflicting; therefore, further studies are necessary to validate these findings, which could be useful in developing a better, more adequate, and personalized management of CKD patients.
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Affiliation(s)
- Ileana Peride
- Clinical Department No. 3, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
- Correspondence: (I.P.); (A.N.)
| | - Mirela Tiglis
- Clinical Department No. 14, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
| | - Tiberiu Paul Neagu
- Clinical Department No. 11, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
| | - Andrei Niculae
- Clinical Department No. 3, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
- Correspondence: (I.P.); (A.N.)
| | - Ionel Alexandru Checherita
- Clinical Department No. 3, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
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14
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Reyes JV, Medina PMB. Renal calcium and magnesium handling in Gitelman syndrome. Am J Transl Res 2022; 14:1-19. [PMID: 35173827 PMCID: PMC8829599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
Gitelman syndrome (GS) is an autosomal recessive salt-losing tubulopathy caused by biallelic inactivating mutations in the SLC12A3 gene. This gene encodes the thiazide-sensitive sodium-chloride cotransporter (NCC) which is exclusively expressed in the distal convoluted tubules (DCT). GS patients classically present with hypokalemic metabolic alkalosis with hypocalciuria and hypomagnesemia. While hypokalemia and metabolic alkalosis are easily explained by effects of the genotypic defect in GS, the mechanisms by which hypomagnesemia and hypocalciuria develop in GS are poorly understood. In this review, we aim to achieve three major objectives. First, present a concise discussion about current understanding on physiologic calcium and magnesium handling in the DCT. Second, integrate expression data from studies on calciotropic and magnesiotropic proteins relevant to the GS disease state. Lastly, provide insights into the possible mechanisms of calcium-magnesium crosstalk relating to the co-occurrence of hypocalciuria and hypomagnesemia in GS models. Our analyses highlight specific areas of study that are valuable in elucidating possible molecular pathways of hypocalciuria and hypomagnesemia in GS.
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Affiliation(s)
- Jeremiah V Reyes
- Biological Models Laboratory, Department of Biochemistry and Molecular Biology, College of Medicine, University of the Philippines Manila Ermita, Manila 1000, Philippines
| | - Paul Mark B Medina
- Biological Models Laboratory, Department of Biochemistry and Molecular Biology, College of Medicine, University of the Philippines Manila Ermita, Manila 1000, Philippines
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Gu X, Li Y, Qi C, Cai K. Biodegradable magnesium phosphates in biomedical applications. J Mater Chem B 2022; 10:2097-2112. [DOI: 10.1039/d1tb02836g] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As an essential element, magnesium is involved in a variety of physiological processes. Magnesium is the second most abundant cation in cells and the fourth most abundant cation in living...
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16
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Abstract
Magnesium (Mg2+) plays an essential role in many biological processes. Mg2+ deficiency is therefore associated with a wide range of clinical effects including muscle cramps, fatigue, seizures and arrhythmias. To maintain sufficient Mg2+ levels, (re)absorption of Mg2+ in the intestine and kidney is tightly regulated. Genetic defects that disturb Mg2+ uptake pathways, as well as drugs interfering with Mg2+ (re)absorption cause hypomagnesemia. The aim of this review is to provide an overview of the molecular mechanisms underlying genetic and drug-induced Mg2+ deficiencies. This leads to the identification of four main mechanisms that are affected by hypomagnesemia-causing mutations or drugs: luminal transient receptor potential melastatin type 6/7-mediated Mg2+ uptake, paracellular Mg2+ reabsorption in the thick ascending limb of Henle's loop, structural integrity of the distal convoluted tubule and Na+-dependent Mg2+ extrusion driven by the Na+/K+-ATPase. Our analysis demonstrates that genetic and drug-induced causes of hypomagnesemia share common molecular mechanisms. Targeting these shared pathways can lead to novel treatment options for patients with hypomagnesemia.
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