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Dąbkowski K, Kreft E, Sałaga-Zaleska K, Chyła-Danił G, Mickiewicz A, Gruchała M, Kuchta A, Jankowski M. Human In Vitro Oxidized Low-Density Lipoprotein (oxLDL) Increases Urinary Albumin Excretion in Rats. Int J Mol Sci 2024; 25:5498. [PMID: 38791535 PMCID: PMC11122078 DOI: 10.3390/ijms25105498] [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: 04/19/2024] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024] Open
Abstract
Hypercholesterolemia-associated oxidative stress increases the formation of oxidized low-density lipoprotein (oxLDL), which can affect endothelial cell function and potentially contribute to renal dysfunction, as reflected by changes in urinary protein excretion. This study aimed to investigate the impact of exogenous oxLDL on urinary excretion of albumin and nephrin. LDL was isolated from a patient with familial hypercholesterolemia (FH) undergoing lipoprotein apheresis (LA) and was oxidized in vitro with Cu (II) ions. Biochemical markers of LDL oxidation, such as TBARS, conjugated dienes, and free ε-amino groups, were measured. Wistar rats were treated with a single intraperitoneal injection of PBS, LDL, or oxLDL (4 mg of protein/kg b.w.). Urine was collected one day before and two days after the injection. We measured blood lipid profiles, urinary protein excretion (specifically albumin and nephrin), and markers of systemic oxidative stress (8-OHdG and 8-iso-PGF2α). The results showed that injection of oxLDL increased urinary albumin excretion by approximately 28% (310 ± 27 μg/24 h vs. 396 ± 26 μg/24 h, p = 0.0003) but had no effect on nephrin excretion. Neither PBS nor LDL had any effect on urinary albumin or nephrin excretion. Additionally, oxLDL did not affect systemic oxidative stress. In conclusion, hypercholesterolemia may adversely affect renal function through oxidatively modified LDL, which interferes with the renal handling of albumin and leads to the development of albuminuria.
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Affiliation(s)
- Kamil Dąbkowski
- Department of Clinical Chemistry, Medical University of Gdańsk, 80-210 Gdańsk, Poland; (K.D.); (E.K.); (K.S.-Z.); (G.C.-D.); (A.K.)
| | - Ewelina Kreft
- Department of Clinical Chemistry, Medical University of Gdańsk, 80-210 Gdańsk, Poland; (K.D.); (E.K.); (K.S.-Z.); (G.C.-D.); (A.K.)
| | - Kornelia Sałaga-Zaleska
- Department of Clinical Chemistry, Medical University of Gdańsk, 80-210 Gdańsk, Poland; (K.D.); (E.K.); (K.S.-Z.); (G.C.-D.); (A.K.)
| | - Gabriela Chyła-Danił
- Department of Clinical Chemistry, Medical University of Gdańsk, 80-210 Gdańsk, Poland; (K.D.); (E.K.); (K.S.-Z.); (G.C.-D.); (A.K.)
| | - Agnieszka Mickiewicz
- 1st Department of Cardiology, Medical University of Gdańsk, 80-210 Gdańsk, Poland; (A.M.); (M.G.)
| | - Marcin Gruchała
- 1st Department of Cardiology, Medical University of Gdańsk, 80-210 Gdańsk, Poland; (A.M.); (M.G.)
| | - Agnieszka Kuchta
- Department of Clinical Chemistry, Medical University of Gdańsk, 80-210 Gdańsk, Poland; (K.D.); (E.K.); (K.S.-Z.); (G.C.-D.); (A.K.)
| | - Maciej Jankowski
- Department of Clinical Chemistry, Medical University of Gdańsk, 80-210 Gdańsk, Poland; (K.D.); (E.K.); (K.S.-Z.); (G.C.-D.); (A.K.)
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Balbotkina EV, Karavashkina TA, Seliverstova EV, Kutina AV. Microalbuminuria in Rats Treated with D-Nitroarginine Methyl Ether. Bull Exp Biol Med 2024; 176:437-441. [PMID: 38491255 DOI: 10.1007/s10517-024-06042-x] [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] [Received: 05/30/2023] [Indexed: 03/18/2024]
Abstract
Microalbuminuria is an early symptom and prognostic marker of the progression of renal pathology. The analysis of the role of anionic components of the renal glomeruli in the albumin retention and the development of a model of minimal changes in the glomerular filter leading to the appearance of microalbuminuria are relevant. The effect of organic cations D-arginine methyl esters (D-AME) and D-nitroarginine (D-NAME) on the excretion of albumin by the kidneys in rats was studied. D-AME had no effect on urinary albumin excretion in rats. D-NAME caused microalbuminuria, which persisted for more than a day and sharply increased after injection of vasopressin. The number of anionic sites labeled with polyethyleneimine decreased in the structures of the glomerular filter. D-NAME-induced microalbuminuria can later serve as a model for studying nephroprotective or damaging factors.
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Affiliation(s)
- E V Balbotkina
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - T A Karavashkina
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - E V Seliverstova
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - A V Kutina
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.
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Chen Y, Li H, Zhang D, Gong Y, Jiang H, Sun H, Wang Y. ANGPT2/CAV1 regulates albumin transcytosis of glomerular endothelial cells under high glucose exposure and is impaired by losartan. Nefrologia 2024; 44:50-60. [PMID: 36842857 DOI: 10.1016/j.nefroe.2022.11.028] [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] [Received: 07/08/2022] [Revised: 11/02/2022] [Accepted: 11/10/2022] [Indexed: 02/28/2023] Open
Abstract
BACKGROUND Microalbuminuria is a common clinical symptom that manifests in the early stages of diabetic kidney disease (DKD) and is also the main feature of glomerular endothelial cells (GECs) injury. There is increasing evidence that the transcytosis of albumin across GECs is closely related to the formation of albuminuria. Our previous studies have shown that angiopoietin 2 (ANGPT2) can inhibit albumin transcytosis across renal tubular epithelial cells by activating caveolin 1 (CAV1) phosphorylation during high glucose (HG) exposure. The role of ANGPT2 in albumin transcytosis across GECs remains unclear. Losartan significantly reduces albuminuria, but the mechanism has not been clarified. METHODS We established an in vitro albumin transcytosis model to investigate the change in albumin transcytosis across human renal glomerular endothelial cells (hrGECs) under normal glucose (NG), high glucose (HG) and losartan intervention. We knocked down ANGPT2 and CAV1 to evaluate their roles in albumin transcytosis across hrGECs and verified the relationship between them. In vivo, DKD mouse models were established and treated with different doses of losartan. Immunohistochemistry and Western blot were used to detect the expression of ANGPT2 and CAV1. RESULTS In vitro, the transcytosis of albumin across hrGECs was significantly increased under high glucose stimulation, and losartan inhibited this process. The expression of ANGPT2 and CAV1 were both increased in hrGECs under HG conditions and losartan intervention reduced the expression of them. Moreover, ANGPT2 downregulation reduced albumin transcytosis in hrGECs by regulating CAV1 expression. In vivo, the expression of ANGPT2 and CAV1 in the glomerulus was both increased significantly in DKD mice. Compared with DKD mice, losartan treatment reduced albuminuria and decreased the expression of ANGPT2 and CAV1 in a dose-dependent manner. CONCLUSIONS ANGPT2 exacerbated albumin transcytosis across GECs by increasing CAV1 expression during HG exposure, thereby increasing albuminuria. Losartan reduces albumin transcytosis and albuminuria formation in DKD by inhibiting the upregulation of ANGPT2 under HG conditions. Our findings suggest that ANGPT2 and CAV1 may be novel therapeutic targets for diabetic albuminuria. In addition, we provide new evidence to elaborate on the mechanism of losartan in the development of DKD.
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Affiliation(s)
- Yang Chen
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Huiqing Li
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Di Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Yi Gong
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Huajun Jiang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Hui Sun
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| | - Yumei Wang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
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Locatelli M, Rottoli D, Mahmoud R, Abbate M, Corna D, Cerullo D, Tomasoni S, Remuzzi G, Zoja C, Benigni A, Macconi D. Endothelial Glycocalyx of Peritubular Capillaries in Experimental Diabetic Nephropathy: A Target of ACE Inhibitor-Induced Kidney Microvascular Protection. Int J Mol Sci 2023; 24:16543. [PMID: 38003732 PMCID: PMC10671403 DOI: 10.3390/ijms242216543] [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: 10/24/2023] [Revised: 11/08/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
Peritubular capillary rarefaction is a recurrent aspect of progressive nephropathies. We previously found that peritubular capillary density was reduced in BTBR ob/ob mice with type 2 diabetic nephropathy. In this model, we searched for abnormalities in the ultrastructure of peritubular capillaries, with a specific focus on the endothelial glycocalyx, and evaluated the impact of treatment with an angiotensin-converting enzyme inhibitor (ACEi). Mice were intracardially perfused with lanthanum to visualise the glycocalyx. Transmission electron microscopy analysis revealed endothelial cell abnormalities and basement membrane thickening in the peritubular capillaries of BTBR ob/ob mice compared to wild-type mice. Remodelling and focal loss of glycocalyx was observed in lanthanum-stained diabetic kidneys, associated with a reduction in glycocalyx components, including sialic acids, as detected through specific lectins. ACEi treatment preserved the endothelial glycocalyx and attenuated the ultrastructural abnormalities of peritubular capillaries. In diabetic mice, peritubular capillary damage was associated with an enhanced tubular expression of heparanase, which degrades heparan sulfate residues of the glycocalyx. Heparanase was also detected in renal interstitial macrophages that expressed tumor necrosis factor-α. All these abnormalities were mitigated by ACEi. Our findings suggest that, in experimental diabetic nephropathy, preserving the endothelial glycocalyx is important in order to protect peritubular capillaries from damage and loss.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Ariela Benigni
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy; (M.L.); (D.R.); (R.M.); (M.A.); (D.C.); (D.C.); (S.T.); (G.R.); (C.Z.); (D.M.)
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5
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Huijink TM, van 't Hof CJ, van Furth LA, de Haan NA, Maassen H, Venema LH, Lammerts RGM, van den Heuvel MC, Hillebrands JL, van den Born J, Berger SP, Leuvenink HGD. Loss of Endothelial Glycocalyx During Normothermic Machine Perfusion of Porcine Kidneys Irrespective of Pressure and Hematocrit. Transplant Direct 2023; 9:e1507. [PMID: 37456589 PMCID: PMC10348736 DOI: 10.1097/txd.0000000000001507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 07/18/2023] Open
Abstract
Normothermic machine perfusion (NMP) is a promising modality for marginal donor kidneys. However, little is known about the effects of NMP on causing endothelial glycocalyx (eGC) injury. This study aims to evaluate the effects of NMP on eGC injury in marginal donor kidneys and whether this is affected by perfusion pressures and hematocrits. Methods Porcine slaughterhouse kidneys (n = 6/group) underwent 35 min of warm ischemia. Thereafter, the kidneys were preserved with oxygenated hypothermic machine perfusion for 3 h. Subsequently, 4 h of NMP was applied using pressure-controlled perfusion with an autologous blood-based solution containing either 12%, 24%, or 36% hematocrit. Pressures of 55, 75, and 95 mm Hg were applied in the 24% group. Perfusate, urine, and biopsy samples were collected to determine both injury and functional parameters. Results During NMP, hyaluronan levels in the perfusate increased significantly (P < 0.0001). In addition, the positivity of glyco-stained glycocalyx decreased significantly over time, both in the glomeruli (P = 0.024) and peritubular capillaries (P = 0.003). The number of endothelial cells did not change during NMP (P = 0.157), whereas glomerular endothelial expression of vascular endothelial growth factor receptor-2 decreased significantly (P < 0.001). Microthrombi formation was significantly increased after NMP. The use of different pressures and hematocrits did not affect functional parameters during perfusion. Conclusions NMP is accompanied with eGC and vascular endothelial growth factor receptor-2 loss, without significant loss of endothelial cells. eGC loss was not affected by the different pressures and hematocrits used. It remains unclear whether endothelial injury during NMP has harmful consequences for the transplanted kidney.
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Affiliation(s)
- Tobias M Huijink
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Cor J van 't Hof
- Department of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - L Annick van Furth
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Nora A de Haan
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Hanno Maassen
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Leonie H Venema
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Rosa G M Lammerts
- Department of Transplantation Immunology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Marius C van den Heuvel
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Jan-Luuk Hillebrands
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Jacob van den Born
- Department of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Stefan P Berger
- Department of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Henri G D Leuvenink
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
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Ingenbleek Y. Revisiting PINI Scoring in Light of Recent Biological Advances. Nutrients 2023; 15:1846. [PMID: 37111065 PMCID: PMC10146499 DOI: 10.3390/nu15081846] [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] [Received: 03/06/2023] [Revised: 04/01/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
The prognostic inflammatory and nutritional index (PINI) is a simple scoring formula allowing the follow-up of dietary protein restriction and infectious complications affecting critically ill patients hospitalized in medical and surgical wards. The World Health organization (WHO) has recently recommended using the binary CRP (C-reactive protein) and AGP (α1-acid glycoprotein) numerators of the PINI formula in underprivileged inhabitants of developing countries to evaluate their (sub)clinical infectious states making their chronic malnutrition worse. These studies, mainly located in Africa and Asia, demonstrate that children and women enduring the combined effects of infectious burden and (micro)nutrient deprivation (principally retinol and iron) usually manifest persistent refractoriness and slackened recovery throughout dietary rehabilitation. The additive measurement of ALB (albumin) and TTR (transthyretin) composing the denominator of the PINI formula is shown to be helpful in grading the downsizing of lean body mass (LBM), a cornerstone of bodybuilding. The confrontation of these four objective parameters thus allows the quantification of the respective importance of nutritional and inflammatory components of any disease process, taking into account that TTR is the sole plasma protein remaining highly correlated to the fluctuations of LBM. The below review highlights the prevailing roles played by protein nutritional states in the release of plasma retinol to target tissues and to the restoration of iron-deficient anemias.
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Affiliation(s)
- Yves Ingenbleek
- Laboratory of Nutrition, Faculty of Pharmacy, University of Strasbourg, Route du Rhin, 67401 Illkirch-Graffenstaden, France
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Kulkarni K, Patel S, Ali R, Hussain T. Angiotensin II type 2 receptor activation preserves megalin in the kidney and prevents proteinuria in high salt diet fed rats. Sci Rep 2023; 13:4277. [PMID: 36922642 PMCID: PMC10017765 DOI: 10.1038/s41598-023-31454-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 03/12/2023] [Indexed: 03/18/2023] Open
Abstract
Proteinuria is a risk factor for and consequence of kidney injury. Angiotensin II type 2 receptor (AT2R) is an emerging reno-protective target and is anti-proteinuric under pathological conditions, including high salt-fed obese animals. However, the mechanisms remain unknown, particularly whether the anti-proteinuric activity of AT2R is independent of its anti-hypertensive and anti-inflammatory effects. In the present study, obese Zucker rats were fed high sodium (4%) diet (HSD) for 48 h, a time in which blood pressure does not change. HSD caused proteinuria without affecting glomerular slit diaphragm proteins (nephrin and podocin), glomerular filtration rate, inflammatory and fibrotic markers (TNFα, IL-6, and TGF-β), ruling out glomerular injury, inflammation and fibrosis but indicating tubular mechanisms of proteinuria. At cellular and molecular levels, we observed a glycogen synthase kinase (GSK)-3β-mediated megalin phosphorylation, and its subsequent endocytosis and lysosomal degradation in HSD-fed rat kidneys. Megalin is a major proximal tubular endocytic protein transporter. The AT2R agonist C21 (0.3 mg/kg/day, i.p.) administration prevented proteinuria and rescued megalin surface expression potentially by activating Akt-mediated phosphorylation and inactivation of GSK-3β in HSD-fed rat kidneys. Overall, AT2R has a direct anti-proteinuric activity, potentially via megalin regulation, and is suggested as a novel target to limit kidney injury.
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Affiliation(s)
- Kalyani Kulkarni
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Health 2, 4349 Martin Luther King Boulevard, Houston, TX, 77204-5037, USA
| | - Sanket Patel
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Health 2, 4349 Martin Luther King Boulevard, Houston, TX, 77204-5037, USA
| | - Riyasat Ali
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Health 2, 4349 Martin Luther King Boulevard, Houston, TX, 77204-5037, USA
| | - Tahir Hussain
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Health 2, 4349 Martin Luther King Boulevard, Houston, TX, 77204-5037, USA.
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Comper WD, Vuchkova J, McCarthy KJ. New insights into proteinuria/albuminuria. Front Physiol 2022; 13:991756. [PMID: 36225307 PMCID: PMC9548894 DOI: 10.3389/fphys.2022.991756] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
The fractional clearance of proteins as measured in healthy human subjects increases 10,000–100,000- fold when studied in nephrotic patients. This remarkable increase cannot be accounted for by extracellular biophysical mechanisms centered at the glomerular filtration barrier. Rather, it is the nephron and its combination of filtration and cellular uptake that can provide a plausible explanation of these fractional clearance changes. The nephron has two regions that critically determine the level proteinuria/albuminuria. Glomerular filtration of plasma proteins is primarily a size selective event that is basically unchanged in acquired and genetic kidney disease. The glomerular concepts of ‘charge selectivity’ and of ‘large pores’, previously used to explain proteinuria, are now recognized to be flawed and non-existent. Filtered proteins then encounter downstream two protein receptors of the Park and Maack type associated with the proximal tubular cell. The high capacity receptor is thought to retrieve the majority of filtered proteins and return them to the blood supply. Inhibition/saturation of this pathway in kidney disease may create the nephrotic condition and hypoproteinemia/hypoalbuminemia. Inhibitors of this pathway (possibly podocyte derived) are still to be identified. A relatively small proportion of the filtered protein is directed towards a high affinity, low capacity receptor that guides the protein to undergo lysosomal degradation. Proteinuria in normoproteinemic states is derived by inhibition of this pathway, such as in diabetes. The combination of glomerular sieving, and the degradation and retrieval pathways can quantitatively account for the changes in fractional clearance of proteins in the nephrotic condition. Finally, the general retrieval of filtered protein by the proximal tubular cell focuses on the teleological importance of this cell as this retrieval represents the third pillar of retrieval that this cell participates in (it also retrieves water and salt).
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Affiliation(s)
- Wayne D. Comper
- Salaqua Diagnostics Inc, New York, NY, United States
- *Correspondence: Wayne D. Comper,
| | | | - Kevin J. McCarthy
- Department of Cellular Biology and Anatomy, LSU Health Sciences Center, Shreveport, LA, United States
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Locatelli M, Macconi D, Corna D, Cerullo D, Rottoli D, Remuzzi G, Benigni A, Zoja C. Sirtuin 3 Deficiency Aggravates Kidney Disease in Response to High-Fat Diet through Lipotoxicity-Induced Mitochondrial Damage. Int J Mol Sci 2022; 23:ijms23158345. [PMID: 35955472 PMCID: PMC9368634 DOI: 10.3390/ijms23158345] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 02/05/2023] Open
Abstract
Sirtuin 3 (SIRT3) is the primary mitochondrial deacetylase that controls the antioxidant pathway and energy metabolism. We previously found that renal Sirt3 expression and activity were reduced in mice with type 2 diabetic nephropathy associated with oxidative stress and mitochondrial abnormalities and that a specific SIRT3 activator improved renal damage. SIRT3 is modulated by diet, and to assess whether Sirt3 deficiency aggravates mitochondrial damage and accelerates kidney disease in response to nutrient overloads, wild-type (WT) and Sirt3−/− mice were fed a high-fat-diet (HFD) or standard diet for 8 months. Sirt3−/− mice on HFD exhibited earlier and more severe albuminuria compared to WT mice, accompanied by podocyte dysfunction and glomerular capillary rarefaction. Mesangial matrix expansion, tubular vacuolization and inflammation, associated with enhanced lipid accumulation, were more evident in Sirt3−/− mice. After HFD, kidneys from Sirt3−/− mice showed more oxidative stress than WT mice, mitochondria ultrastructural damage in tubular cells, and a reduction in mitochondrial mass and energy production. Our data demonstrate that Sirt3 deficiency renders mice more prone to developing oxidative stress and mitochondrial abnormalities in response to HFD, resulting in more severe kidney diseases, and this suggests that mitochondria protection may be a method to prevent HFD-induced renal injury.
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Zha D, Fu M, Qian Y. Vascular Endothelial Glycocalyx Damage and Potential Targeted Therapy in COVID-19. Cells 2022; 11:cells11121972. [PMID: 35741101 PMCID: PMC9221624 DOI: 10.3390/cells11121972] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/10/2022] [Accepted: 06/17/2022] [Indexed: 02/06/2023] Open
Abstract
COVID-19 is a highly infectious respiratory disease caused by a new coronavirus known as SARS-CoV-2. COVID-19 is characterized by progressive respiratory failure resulting from diffuse alveolar damage, inflammatory infiltrates, endotheliitis, and pulmonary and systemic coagulopathy forming obstructive microthrombi with multi-organ dysfunction, indicating that endothelial cells (ECs) play a central role in the pathogenesis of COVID-19. The glycocalyx is defined as a complex gel-like layer of glycosylated lipid–protein mixtures, which surrounds all living cells and acts as a buffer between the cell and the extracellular matrix. The endothelial glycocalyx layer (EGL) plays an important role in vascular homeostasis via regulating vascular permeability, cell adhesion, mechanosensing for hemodynamic shear stresses, and antithrombotic and anti-inflammatory functions. Here, we review the new findings that described EGL damage in ARDS, coagulopathy, and the multisystem inflammatory disease associated with COVID-19. Mechanistically, the inflammatory mediators, reactive oxygen species (ROS), matrix metalloproteases (MMPs), the glycocalyx fragments, and the viral proteins may contribute to endothelial glycocalyx damage in COVID-19. In addition, the potential therapeutic strategies targeting the EGL for the treatment of severe COVID-19 are summarized and discussed.
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Affiliation(s)
- Duoduo Zha
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang 330031, China;
| | - Mingui Fu
- Shock/Trauma Research Center, Department of Biomedical Sciences, School of Medicine, University of Missouri Kansas City, Kansas City, MO 64108, USA;
| | - Yisong Qian
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang 330031, China;
- Correspondence:
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Comper WD. Commentary: The Glomerular Endothelium Restricts Albumin Filtration. Front Med (Lausanne) 2022; 9:861566. [PMID: 35295597 PMCID: PMC8919079 DOI: 10.3389/fmed.2022.861566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
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