1
|
Huang Y, Wang J, Mancino V, Pham J, O’Grady C, Li H, Jiang K, Chin D, Poon C, Ho PY, Gyarmati G, Peti-Peterdi J, Hallows KR, Chung EJ. Oral delivery of nanomedicine for genetic kidney disease. PNAS NEXUS 2024; 3:pgae187. [PMID: 38807632 PMCID: PMC11131023 DOI: 10.1093/pnasnexus/pgae187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 05/01/2024] [Indexed: 05/30/2024]
Abstract
Chronic and genetic kidney diseases such as autosomal dominant polycystic kidney disease (ADPKD) have few therapeutic options, and clinical trials testing small molecule drugs have been unfavorable due to low kidney bioavailability and adverse side effects. Although nanoparticles can be designed to deliver drugs directly to the diseased site, there are no kidney-targeted nanomedicines clinically available, and most FDA-approved nanoparticles are administered intravenously which is not ideal for chronic diseases. To meet these challenges of chronic diseases, we developed a biomaterials-based strategy using chitosan particles (CP) for oral delivery of therapeutic, kidney-targeting peptide amphiphile micelles (KMs). We hypothesized that encapsuling KMs into CP would enhance the bioavailability of KMs upon oral administration given the high stability of chitosan in acidic conditions and mucoadhesive properties enabling absorption within the intestines. To test this, we evaluated the mechanism of KM access to the kidneys via intravital imaging and investigated the KM biodistribution in a porcine model. Next, we loaded KMs carrying the ADPKD drug metformin into CP (KM-CP-met) and measured in vitro therapeutic effect. Upon oral administration in vivo, KM-CP-met showed significantly greater bioavailability and accumulation in the kidneys as compared to KM only or free drug. As such, KM-CP-met treatment in ADPKD mice (Pkd1fl/fl;Pax8-rtTA;Tet-O-Cre which develops the disease over 120 days and mimics the slow development of ADPKD) showed enhanced therapeutic efficacy without affecting safety despite repeated treatment. Herein, we demonstrate the potential of KM-CP as a nanomedicine strategy for oral delivery for the long-term treatment of chronic kidney diseases.
Collapse
Affiliation(s)
- Yi Huang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Jonathan Wang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Valeria Mancino
- Department of Medicine, Division of Nephrology and Hypertension, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- USC/UKRO Kidney Research Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Jessica Pham
- Department of Medicine, Division of Nephrology and Hypertension, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- USC/UKRO Kidney Research Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Colette O’Grady
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Hui Li
- Department of Medicine, Division of Nephrology and Hypertension, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- USC/UKRO Kidney Research Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Kairui Jiang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Deborah Chin
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Christopher Poon
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Pei-Yin Ho
- Department of Medicine, Division of Nephrology and Hypertension, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- USC/UKRO Kidney Research Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Georgina Gyarmati
- Department of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - János Peti-Peterdi
- Department of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - Kenneth R Hallows
- Department of Medicine, Division of Nephrology and Hypertension, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- USC/UKRO Kidney Research Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Eun Ji Chung
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Medicine, Division of Nephrology and Hypertension, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA
- Department of Surgery, Division of Vascular Surgery and Endovascular Therapy, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
- Department of Stem Cell Biology and Regenerative Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90033, USA
- Bridge Institute, University of Southern California, Los Angeles, CA 90089, USA
| |
Collapse
|
2
|
Staruschenko A, Alexander RT, Caplan MJ, Ilatovskaya DV. Calcium signalling and transport in the kidney. Nat Rev Nephrol 2024:10.1038/s41581-024-00835-z. [PMID: 38641658 DOI: 10.1038/s41581-024-00835-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2024] [Indexed: 04/21/2024]
Abstract
The kidney plays a pivotal role in regulating calcium levels within the body. Approximately 98% of the filtered calcium is reabsorbed in the nephron, and this process is tightly controlled to maintain calcium homeostasis, which is required to facilitate optimal bone mineralization, preserve serum calcium levels within a narrow range, and support intracellular signalling mechanisms. The maintenance of these functions is attributed to a delicate balance achieved by various calcium channels, transporters, and calcium-binding proteins in renal cells. Perturbation of this balance due to deficiency or dysfunction of calcium channels and calcium-binding proteins can lead to severe complications. For example, polycystic kidney disease is linked to aberrant calcium transport and signalling. Furthermore, dysregulation of calcium levels can promote the formation of kidney stones. This Review provides an updated description of the key aspects of calcium handling in the kidney, focusing on the function of various calcium channels and the physiological stimuli that control these channels or are communicated through them. A discussion of the role of calcium as an intracellular second messenger and the pathophysiology of renal calcium dysregulation, as well as a summary of gaps in knowledge and future prospects, are also included.
Collapse
Affiliation(s)
- Alexander Staruschenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA.
- Hypertension and Kidney Research Center, University of South Florida, Tampa, FL, USA.
- James A. Haley Veterans Hospital, Tampa, FL, USA.
| | - R Todd Alexander
- Department of Paediatrics, University of Alberta, Edmonton, AB, Canada
- Women's and Children's Health Institute, Edmonton, AB, Canada
| | - Michael J Caplan
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Daria V Ilatovskaya
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| |
Collapse
|
3
|
Bordoni L, Kristensen AM, Sardella D, Kidmose H, Pohl L, Krag SRP, Schiessl IM. Longitudinal tracking of acute kidney injury reveals injury propagation along the nephron. Nat Commun 2023; 14:4407. [PMID: 37479698 PMCID: PMC10362041 DOI: 10.1038/s41467-023-40037-y] [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: 01/17/2023] [Accepted: 07/10/2023] [Indexed: 07/23/2023] Open
Abstract
Acute kidney injury (AKI) is an important risk factor for chronic kidney disease (CKD), but the underlying mechanisms of failed tubule repair and AKI-CKD transition are incompletely understood. In this study, we aimed for dynamic tracking of tubule injury and remodeling to understand if focal injury upon AKI may spread over time. Here, we present a model of AKI, in which we rendered only half of the kidney ischemic. Using serial intravital 2-photon microscopy and genetic identification of cycling cells, we tracked dynamic tissue remodeling in post- and non-ischemic kidney regions simultaneously and over 3 weeks. Spatial and temporal analysis of cycling cells relative to initial necrotic cell death demonstrated pronounced injury propagation and expansion into non-necrotic tissue regions, which predicted tubule atrophy with epithelial VCAM1 expression. In summary, our longitudinal analyses of tubule injury, remodeling, and fate provide important insights into AKI pathology.
Collapse
Affiliation(s)
- Luca Bordoni
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | | | - Donato Sardella
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Hanne Kidmose
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Layla Pohl
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | | |
Collapse
|
4
|
Radmilović MD, Drvenica IT, Rabasović MD, Ilić VL, Pavlović D, Oasa S, Vukojević V, Perić M, Nikolić SN, Krmpot AJ. Interactions of ultrashort laser pulses with hemoglobin: Photophysical aspects and potential applications. Int J Biol Macromol 2023:125312. [PMID: 37302636 DOI: 10.1016/j.ijbiomac.2023.125312] [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: 03/21/2023] [Revised: 05/16/2023] [Accepted: 06/08/2023] [Indexed: 06/13/2023]
Abstract
Hemoglobin (Hb), a life-sustaining and highly abundant erythrocyte protein, is not readily fluorescent. A few studies have already reported Two-Photon Excited Fluorescence (TPEF) of Hb, however, the mechanisms through which Hb becomes fluorescent upon interaction with ultrashort laser pulses are not completely understood. Here, we characterized photophysically this interaction on Hb thin film and erythrocytes using fluorescence spectroscopy upon single-photon/two-photon absorption, and UV-VIS single-photon absorption spectroscopy. A gradual increase of the fluorescence intensity, ending up with saturation, is observed upon prolonged exposure of Hb thin layer and erythrocytes to ultrashort laser pulses at 730 nm. When compared to protoporphyrin IX (PpIX) and oxidized Hb by H2O2, TPEF spectra from a thin Hb film and erythrocytes showed good mutual agreement, broad peaking at 550 nm, supporting hemoglobin undergoes degradation and that same fluorescent specie(s) originating from the heme moiety are generated. The uniform square shaped patterns of the fluorescent photoproduct exhibited the same level of the fluorescence intensity even after 12 weeks from the formation, indicating high photoproduct stability. We finally demonstrated the full potential of the formed Hb photoproduct with TPEF scanning microscopy towards spatiotemporally controlled micropatterning in HTF and single human erythrocyte labelling and tracking in the whole blood.
Collapse
Affiliation(s)
| | - Ivana T Drvenica
- Institute for Medical Research, National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | | | - Vesna Lj Ilić
- Institute for Medical Research, National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Danica Pavlović
- Institute of Physics Belgrade, University of Belgrade, Belgrade, Serbia
| | - Sho Oasa
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Vladana Vukojević
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Mina Perić
- Faculty of Biology, University of Belgrade, Belgrade, Serbia; Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Stanko N Nikolić
- Institute of Physics Belgrade, University of Belgrade, Belgrade, Serbia; Division of Arts and Sciences, Texas A&M University at Qatar, Doha, Qatar
| | - Aleksandar J Krmpot
- Institute of Physics Belgrade, University of Belgrade, Belgrade, Serbia; Division of Arts and Sciences, Texas A&M University at Qatar, Doha, Qatar.
| |
Collapse
|
5
|
Valentino M, Bianco V, Miccio L, Memmolo P, Brancato V, Libretti P, Gambacorta M, Salvatore M, Ferraro P. Beyond conventional microscopy: Observing kidney tissues by means of fourier ptychography. Front Physiol 2023; 14:1120099. [PMID: 36860516 PMCID: PMC9968938 DOI: 10.3389/fphys.2023.1120099] [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: 12/09/2022] [Accepted: 02/01/2023] [Indexed: 02/17/2023] Open
Abstract
Kidney microscopy is a mainstay in studying the morphological structure, physiology and pathology of kidney tissues, as histology provides important results for a reliable diagnosis. A microscopy modality providing at same time high-resolution images and a wide field of view could be very useful for analyzing the whole architecture and the functioning of the renal tissue. Recently, Fourier Ptychography (FP) has been proofed to yield images of biology samples such as tissues and in vitro cells while providing high resolution and large field of view, thus making it a unique and attractive opportunity for histopathology. Moreover, FP offers tissue imaging with high contrast assuring visualization of small desirable features, although with a stain-free mode that avoids any chemical process in histopathology. Here we report an experimental measuring campaign for creating the first comprehensive and extensive collection of images of kidney tissues captured by this FP microscope. We show that FP microscopy unlocks a new opportunity for the physicians to observe and judge renal tissue slides through the novel FP quantitative phase-contrast microscopy. Phase-contrast images of kidney tissue are analyzed by comparing them with the corresponding renal images taken under a conventional bright-field microscope both for stained and unstained tissue samples of different thicknesses. In depth discussion on the advantages and limitations of this new stain-free microscopy modality is reported, showing its usefulness over the classical light microscopy and opening a potential route for using FP in clinical practice for histopathology of kidney.
Collapse
Affiliation(s)
- Marika Valentino
- National Research Council (CNR) of Italy, Institute of Applied Sciences and Intelligent Systems (ISASI), Pozzuoli, Italy,Department of Electric and Information Technologies Engineering, University of Naples “Federico II”, Naples, Italy
| | - Vittorio Bianco
- National Research Council (CNR) of Italy, Institute of Applied Sciences and Intelligent Systems (ISASI), Pozzuoli, Italy,*Correspondence: Vittorio Bianco, ; Marcello Gambacorta,
| | - Lisa Miccio
- National Research Council (CNR) of Italy, Institute of Applied Sciences and Intelligent Systems (ISASI), Pozzuoli, Italy
| | - Pasquale Memmolo
- National Research Council (CNR) of Italy, Institute of Applied Sciences and Intelligent Systems (ISASI), Pozzuoli, Italy
| | | | | | - Marcello Gambacorta
- IRCCS SYNLAB SDN, Naples, Italy,*Correspondence: Vittorio Bianco, ; Marcello Gambacorta,
| | | | - Pietro Ferraro
- National Research Council (CNR) of Italy, Institute of Applied Sciences and Intelligent Systems (ISASI), Pozzuoli, Italy
| |
Collapse
|
6
|
Sardella D, Kristensen AM, Bordoni L, Kidmose H, Shahrokhtash A, Sutherland DS, Frische S, Schiessl IM. Serial intravital 2-photon microscopy and analysis of the kidney using upright microscopes. Front Physiol 2023; 14:1176409. [PMID: 37168225 PMCID: PMC10164931 DOI: 10.3389/fphys.2023.1176409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/03/2023] [Indexed: 05/13/2023] Open
Abstract
Serial intravital 2-photon microscopy of the kidney and other abdominal organs is a powerful technique to assess tissue function and structure simultaneously and over time. Thus, serial intravital microscopy can capture dynamic tissue changes during health and disease and holds great potential to characterize (patho-) physiological processes with subcellular resolution. However, successful image acquisition and analysis require significant expertise and impose multiple potential challenges. Abdominal organs are rhythmically displaced by breathing movements which hamper high-resolution imaging. Traditionally, kidney intravital imaging is performed on inverted microscopes where breathing movements are partly compensated by the weight of the animal pressing down. Here, we present a custom and easy-to-implement setup for intravital imaging of the kidney and other abdominal organs on upright microscopes. Furthermore, we provide image processing protocols and a new plugin for the free image analysis software FIJI to process multichannel fluorescence microscopy data. The proposed image processing pipelines cover multiple image denoising algorithms, sample drift correction using 2D registration, and alignment of serial imaging data collected over several weeks using landmark-based 3D registration. The provided tools aim to lower the barrier of entry to intravital microscopy of the kidney and are readily applicable by biomedical practitioners.
Collapse
Affiliation(s)
- Donato Sardella
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- *Correspondence: Ina Maria Schiessl, ; Donato Sardella,
| | | | - Luca Bordoni
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Hanne Kidmose
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Ali Shahrokhtash
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | | | | | - Ina Maria Schiessl
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- *Correspondence: Ina Maria Schiessl, ; Donato Sardella,
| |
Collapse
|
7
|
GYARMATI GEORGINA, TOMA ILDIKÓ, IZUHARA AUDREY, BURFORD JAMESL, SHROFF URVINIKHIL, PAPADOURI STELLA, DEEPAK SACHIN, PETI-PETERDI JÁNOS. The role of TRPC6 calcium channels and P2 purinergic receptors in podocyte mechanical and metabolic sensing. Physiol Int 2021; 109:2021.00205. [PMID: 34978536 PMCID: PMC9200898 DOI: 10.1556/2060.2021.00205] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 11/22/2021] [Indexed: 12/17/2022]
Abstract
Podocyte calcium (Ca2+) signaling plays important roles in the (patho)physiology of the glomerular filtration barrier. Overactivation of podocyte transient receptor potential canonical (TRPC) channels including TRPC6 and purinergic signaling via P2 receptors that are known mechanosensors can increase podocyte intracellular Ca2+ levels ([Ca2+]i) and cause cell injury, proteinuria and glomerular disease including in diabetes. However, important mechanistic details of the trigger and activation of these pathways in vivo in the intact glomerular environment are lacking. Here we show direct visual evidence that podocytes can sense mechanical overload (increased glomerular capillary pressure) and metabolic alterations (increased plasma glucose) via TRPC6 and purinergic receptors including P2Y2. Multiphoton microscopy of podocyte [Ca2+]i was performed in vivo using wild-type and TRPC6 or P2Y2 knockout (KO) mice expressing the calcium reporter GCaMP3/5 only in podocytes and in vitro using freshly dissected microperfused glomeruli. Single-nephron intra-glomerular capillary pressure elevations induced by obstructing the efferent arteriole lumen with laser-induced microthrombus in vivo and by a micropipette in vitro triggered >2-fold increases in podocyte [Ca2+]i. These responses were blocked in TRPC6 and P2Y2 KO mice. Acute elevations of plasma glucose caused >4-fold increases in podocyte [Ca2+]i that were abolished by pharmacological inhibition of TRPC6 or P2 receptors using SAR7334 or suramin treatment, respectively. This study established the role of Ca2+ signaling via TRPC6 channels and P2 receptors in mechanical and metabolic sensing of podocytes in vivo, which are promising therapeutic targets in conditions with high intra-glomerular capillary pressure and plasma glucose, such as diabetic and hypertensive nephropathy.
Collapse
Affiliation(s)
- GEORGINA GYARMATI
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - ILDIKÓ TOMA
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - AUDREY IZUHARA
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - JAMES L. BURFORD
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - URVI NIKHIL SHROFF
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - STELLA PAPADOURI
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - SACHIN DEEPAK
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| | - JÁNOS PETI-PETERDI
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, USA
| |
Collapse
|
8
|
Shroff UN, Gyarmati G, Izuhara A, Deepak S, Peti-Peterdi J. A new view of macula densa cell protein synthesis. Am J Physiol Renal Physiol 2021; 321:F689-F704. [PMID: 34693742 PMCID: PMC8714974 DOI: 10.1152/ajprenal.00222.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 10/12/2021] [Accepted: 10/15/2021] [Indexed: 11/22/2022] Open
Abstract
Macula densa (MD) cells, a chief sensory cell type in the nephron, are endowed with unique microanatomic features including a high density of protein synthetic organelles and secretory vesicles in basal cell processes ("maculapodia") that suggest a so far unknown high rate of MD protein synthesis. This study aimed to explore the rate and regulation of MD protein synthesis and their effects on glomerular function using novel transgenic mouse models, newly established fluorescence cell biology techniques, and intravital microscopy. Sox2-tdTomato kidney tissue sections and an O-propargyl puromycin incorporation-based fluorescence imaging assay showed that MD cells have the highest level of protein synthesis within the kidney cortex followed by intercalated cells and podocytes. Genetic gain of function of mammalian target of rapamycin (mTOR) signaling specifically in MD cells (in MD-mTORgof mice) or their physiological activation by low-salt diet resulted in further significant increases in the synthesis of MD proteins. Specifically, these included both classic and recently identified MD-specific proteins such as cyclooxygenase 2, microsomal prostaglandin E2 synthase 1, and pappalysin 2. Intravital imaging of the kidney using multiphoton microscopy showed significant increases in afferent and efferent arteriole and glomerular capillary diameters and blood flow in MD-mTORgof mice coupled with an elevated glomerular filtration rate. The presently identified high rate of MD protein synthesis that is regulated by mTOR signaling is a novel component of the physiological activation and glomerular hemodynamic regulatory functions of MD cells that remains to be fully characterized.NEW & NOTEWORTHY This study discovered the high rate of protein synthesis in macula densa (MD) cells by applying direct imaging techniques with single cell resolution. Physiological activation and mammalian target of rapamycin signaling played important regulatory roles in this process. This new feature is a novel component of the tubuloglomerular cross talk and glomerular hemodynamic regulatory functions of MD cells. Future work is needed to elucidate the nature and (patho)physiological role of the specific proteins synthesized by MD cells.
Collapse
Affiliation(s)
- Urvi Nikhil Shroff
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
| | - Georgina Gyarmati
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
| | - Audrey Izuhara
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
| | - Sachin Deepak
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
- Department of Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
| | - János Peti-Peterdi
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
| |
Collapse
|
9
|
Gyarmati G, Shroff UN, Izuhara A, Hou X, Da Sacco S, Sedrakyan S, Lemley KV, Amann K, Perin L, Peti-Peterdi J. Intravital imaging reveals glomerular capillary distension and endothelial and immune cell activation early in Alport syndrome. JCI Insight 2021; 7:152676. [PMID: 34793332 PMCID: PMC8765042 DOI: 10.1172/jci.insight.152676] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 11/17/2021] [Indexed: 11/17/2022] Open
Abstract
Alport syndrome (AS) is a genetic disorder caused by mutations in type IV collagen that lead to defective glomerular basement membrane, glomerular filtration barrier (GFB) damage, and progressive chronic kidney disease. While the genetic basis of AS is well known, the molecular and cellular mechanistic details of disease pathogenesis have been elusive, hindering the development of mechanism-based therapies. Here, we performed intravital multiphoton imaging of the local kidney tissue microenvironment in a X-linked AS mouse model to directly visualize the major drivers of AS pathology. Severely distended glomerular capillaries and aneurysms were found accompanied by numerous microthrombi, increased glomerular endothelial surface layer (glycocalyx) and immune cell homing, GFB albumin leakage, glomerulosclerosis, and interstitial fibrosis by 5 months of age, with an intermediate phenotype at 2 months. Renal histology in mouse or patient tissues largely failed to detect capillary aberrations. Treatment of AS mice with hyaluronidase or the ACE inhibitor enalapril reduced the excess glomerular endothelial glycocalyx and blocked immune cell homing and GFB albumin leakage. This study identified central roles of glomerular mechanical forces and endothelial and immune cell activation early in AS, which could be therapeutically targeted to reduce mechanical strain and local tissue inflammation and improve kidney function.
Collapse
Affiliation(s)
- Georgina Gyarmati
- Department of Physiology and Neuroscience, University of Southern California, Los Angeles, United States of America
| | - Urvi Nikhil Shroff
- Department of Physiology and Neuroscience, University of Southern California, Los Angeles, United States of America
| | - Audrey Izuhara
- Department of Physiology and Neuroscience, University of Southern California, Los Angeles, United States of America
| | - Xiaogang Hou
- Division of Urology, Children's Hospital Los Angeles, Los Angeles, United States of America
| | - Stefano Da Sacco
- Division of Urology, Children's Hospital Los Angeles, Los Angeles, United States of America
| | - Sargis Sedrakyan
- Division of Urology, Children's Hospital Los Angeles, Los Angeles, United States of America
| | - Kevin V Lemley
- Department of Pediatics, Children's Hospital Los Angeles, Los angeles, United States of America
| | - Kerstin Amann
- Department of Nephropathology, Friedrich Alexander University, Erlangen, Germany
| | - Laura Perin
- Division of Urology, Children's Hospital Los Angeles, Los Angeles, United States of America
| | - János Peti-Peterdi
- Department of Physiology and Neuroscience, University of Southern California, Los Angeles, United States of America
| |
Collapse
|
10
|
Abstract
AbstractAcute kidney injury (AKI) is a common clinical symptom, which is mainly manifested by elevated serum creatinine and blood urea nitrogen levels. When AKI is not repaired in time, the patient is prone to develop chronic kidney disease (CKD). The kidney is composed of more than 30 different cells, and its structure is complex. It is extremely challenging to understand the lineage relationships and cell fate of these cells in the process of kidney injury and regeneration. Since the 20th century, lineage tracing technology has provided an important mean for studying organ development, tissue damage repair, and the differentiation and fate of single cells. However, traditional lineage tracing methods rely on sacrificing animals to make tissue slices and then take snapshots with conventional imaging tools to obtain interesting information. This method cannot achieve dynamic and continuous monitoring of cell actions on living animals. As a kind of intravital microscopy (IVM), two-photon microscopy (TPM) has successfully solved the above problems. Because TPM has the ability to penetrate deep tissues and can achieve imaging at the single cell level, lineage tracing technology with TPM is gradually becoming popular. In this review, we provided the key technical elements of lineage tracing, and how to use intravital imaging technology to visualize and quantify the fate of renal cells.
Collapse
|
11
|
Abstract
Renal epithelial cells show remarkable regenerative capacity to recover from acute injury, which involves specific phenotypic changes, but also significant profibrotic tubule-interstitial crosstalk. Tubule-derived profibrotic stimuli and subsequent myofibroblast activation and extracellular matrix deposition have been linked closely with decline of renal function and nephron loss. However, recent data have questioned the view of purely detrimental effects of myofibroblast activation in the injured kidney and even suggested its beneficial role for epithelial regeneration. This article reviews the current understanding of the underlying mechanisms of tubular cell turnover, new suggested pathways of proregenerative tubular-interstitial crosstalk, and relevant insights of proliferation-enhancing effects of myofibroblasts on epithelial cells in nonrenal tissues.
Collapse
|
12
|
Gyarmati G, Shroff UN, Riquier-Brison A, Kriz W, Kaissling B, Neal CR, Arkill KP, Ahmadi N, Gill IS, Moon JY, Desposito D, Peti-Peterdi J. A new view of macula densa cell microanatomy. Am J Physiol Renal Physiol 2021; 320:F492-F504. [PMID: 33491562 DOI: 10.1152/ajprenal.00546.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Although macula densa (MD) cells are chief regulatory cells in the nephron with unique microanatomical features, they have been difficult to study in full detail due to their inaccessibility and limitations in earlier microscopy techniques. The present study used a new mouse model with a comprehensive imaging approach to visualize so far unexplored microanatomical features of MD cells, their regulation, and functional relevance. MD-GFP mice with conditional and partial induction of green fluorescent protein (GFP) expression, which specifically and intensely illuminated only single MD cells, were used with fluorescence microscopy of fixed tissue and live MD cells in vitro and in vivo with complementary electron microscopy of the rat, rabbit, and human kidney. An elaborate network of major and minor cell processes, here named maculapodia, were found at the cell base, projecting toward other MD cells and the glomerular vascular pole. The extent of maculapodia showed upregulation by low dietary salt intake and the female sex. Time-lapse imaging of maculapodia revealed highly dynamic features including rapid outgrowth and an extensive vesicular transport system. Electron microscopy of rat, rabbit, and human kidneys and three-dimensional volume reconstruction in optically cleared whole-mount MD-GFP mouse kidneys further confirmed the presence and projections of maculapodia into the extraglomerular mesangium and afferent and efferent arterioles. The newly identified dynamic and secretory features of MD cells suggest the presence of novel functional and molecular pathways of cell-to-cell communication in the juxtaglomerular apparatus between MD cells and between MD and other target cells.NEW & NOTEWORTHY This study illuminated a physiologically regulated dense network of basal cell major and minor processes (maculapodia) in macula densa (MD) cells. The newly identified dynamic and secretory features of these microanatomical structures suggest the presence of novel functional and molecular pathways of cell-to-cell communication in the juxtaglomerular apparatus between MD and other target cells. Detailed characterization of the function and molecular details of MD cell intercellular communications and their role in physiology and disease warrant further studies.
Collapse
Affiliation(s)
- Georgina Gyarmati
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
| | - Urvi Nikhil Shroff
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
| | - Anne Riquier-Brison
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
| | - Wilhelm Kriz
- Centre for Biomedicine and Medical Technology Mannheim, Neuroanatomy, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | | | - Christopher R Neal
- Bristol Renal, Bristol Heart Institute, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Kenton P Arkill
- Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Biodiscovery Institute, University Park, United Kingdom
| | - Nariman Ahmadi
- Institute of Urology, Catherine & Joseph Aresty Department of Urology, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Inderbir S Gill
- Institute of Urology, Catherine & Joseph Aresty Department of Urology, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Ju-Young Moon
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
| | - Dorinne Desposito
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
| | - János Peti-Peterdi
- Departments of Physiology and Neuroscience, and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California
| |
Collapse
|