scholarly journals Beyond a Passive Conduit: Implications of Lymphatic Biology for Kidney Diseases

2020 ◽  
Vol 31 (6) ◽  
pp. 1178-1190 ◽  
Author(s):  
Daniyal J. Jafree ◽  
David A. Long

The kidney contains a network of lymphatic vessels that clear fluid, small molecules, and cells from the renal interstitium. Through modulating immune responses and via crosstalk with surrounding renal cells, lymphatic vessels have been implicated in the progression and maintenance of kidney disease. In this Review, we provide an overview of the development, structure, and function of lymphatic vessels in the healthy adult kidney. We then highlight the contributions of lymphatic vessels to multiple forms of renal pathology, emphasizing CKD, transplant rejection, and polycystic kidney disease and discuss strategies to target renal lymphatics using genetic and pharmacologic approaches. Overall, we argue the case for lymphatics playing a fundamental role in renal physiology and pathology and treatments modulating these vessels having therapeutic potential across the spectrum of kidney disease.

Author(s):  
Diana Hamdan ◽  
Lisa A. Robinson

Excessive infiltration of immune cells into the kidney is a key feature of acute and chronic kidney diseases. The family of chemokines are key drivers of this process. CX3CL1 (fractalkine) is one of two unique chemokines synthesized as a transmembrane protein which undergoes proteolytic cleavage to generate a soluble species. Through interacting with its cognate receptor, CX3CR1, CX3CL1 was originally shown to act as a conventional chemoattractant in the soluble form, and as an adhesion molecule in the transmembrane form. Since then, other functions of CX3CL1 beyond leukocyte recruitment have been described, including cell survival, immunosurveillance, and cell-mediated cytotoxicity. This review summarizes diverse roles of CX3CL1 in kidney disease and potential uses as a therapeutic target and novel biomarker. As the CX3CL1-CX3CR1 axis has been shown to contribute to both detrimental and protective effects in various kidney diseases, a thorough understanding of how the expression and function of CX3CL1 are regulated is needed to unlock its therapeutic potential.


Metabolites ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 58
Author(s):  
Xiaoqin Zhang ◽  
Xiaogang Li

Ferroptosis is a newly identified form of regulated cell death driven by iron-dependent phospholipid peroxidation and oxidative stress. Ferroptosis has distinct biological and morphology characteristics, such as shrunken mitochondria when compared to other known regulated cell deaths. The regulation of ferroptosis includes different molecular mechanisms and multiple cellular metabolic pathways, including glutathione/glutathione peroxidase 4(GPX4) signaling pathways, which are involved in the amino acid metabolism and the activation of GPX4; iron metabolic signaling pathways, which are involved in the regulation of iron import/export and the storage/release of intracellular iron through iron-regulatory proteins (IRPs), and lipid metabolic signaling pathways, which are involved in the metabolism of unsaturated fatty acids in cell membranes. Ferroptosis plays an essential role in the pathology of various kidneys diseases, including acute kidney injury (AKI), chronic kidney disease (CKD), autosomal dominant polycystic kidney disease (ADPKD), and renal cell carcinoma (RCC). Targeting ferroptosis with its inducers/initiators and inhibitors can modulate the progression of kidney diseases in animal models. In this review, we discuss the characteristics of ferroptosis and the ferroptosis-based mechanisms, highlighting the potential role of the main ferroptosis-associated metabolic pathways in the treatment and prevention of various kidney diseases.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Mingxuan Chi ◽  
Kuai Ma ◽  
Jing Wang ◽  
Zhaolun Ding ◽  
Yunlong Li ◽  
...  

The human gut microbiota is a complex cluster composed of 100 trillion microorganisms, which holds a symbiotic relationship with the host under normal circumstances. Intestinal flora can facilitate the treatment of human metabolic dysfunctions and interact with the intestinal tract, which could influence intestinal tolerance, immunity, and sensitivity to inflammation. In recent years, significant interests have evolved on the association of intestinal microbiota and kidney diseases within the academic circle. Abnormal changes in intestinal microbiota, known as dysbiosis, can affect the integrity of the intestinal barrier, resulting in the bacterial translocation, production, and accumulation of dysbiotic gut-derived metabolites, such as urea, indoxyl sulfate (IS), and p-cresyl sulfate (PCS). These processes lead to the abnormal activation of immune cells; overproduction of antibodies, immune complexes, and inflammatory factors; and inflammatory cell infiltration that can directly or indirectly cause damage to the renal parenchyma. The aim of this review is to summarize the role of intestinal flora in the development and progression of several renal diseases, such as lupus nephritis, chronic kidney disease, diabetic nephropathy, and renal ischemia-reperfusion injury. Further research on these mechanisms should provide insights into the therapeutic potential of regulating intestinal flora and intervening related molecular targets for the abovementioned nephropathy.


2020 ◽  
Vol 10 (3) ◽  
Author(s):  
Flávia Silveira ◽  
Káthia Zuntini ◽  
Márcia Silveira ◽  
Lohanna Tavares ◽  
Juliana Mendes ◽  
...  

OBJECTIVES: This study aims to present the confirmed cases of SARS-CoV-2 infection in pediatric patients with chronic and acute kidney diseases admitted to a tertiary pediatric hospital. METHODS: Descriptive and retrospective observational study with all children hospitalized between March and June 2020 who had, simultaneously, SARS-CoV-2 infection and renal pathologies. Of this total of patients, those who had another underlying disease besides the renal disease were excluded. RESULTS: During the period, nine children with kidney disease were admitted to the hospital and had infection confirmed by the new coronavirus through positive RT-PCR. Regarding the underlying disease, seven had only kidney disease, three of whom had stage 5 chronic kidney disease; one, with stage 1 chronic kidney disease; one, with cortic-sensitive nephrotic syndrome; and two, with acute kidney injury. Two patients in this study had already undergone kidney transplantation, used immunosuppressants and had their doses reduced due to the infectious condition. Only one required oxygen therapy and transfer to the intensive care unit, but was not intubated and returned to the ward within 24 hours. CONCLUSIONS: According to the cases described, the pediatric population with kidney disease, including those using immunosuppressants due to acute transplant rejection, seems to evolve without severe COVID-19, therefore there is no great divergence in relation to the population of the same healthy age group.


Written for the busy nephrologist and internist who need easy to access information on the diagnosis, investigation, and treatment of patients with kidney disease, the Oxford Desk Reference Nephrology is presented in a way that is not only easy to read and digest but also is detailed enough to allow an in depth understanding of the complex mix of metabolic, immunological, and genetic causes of both acute and chronic kidney disease. The kidneys are rarely affected by disease in isolation; the book comprehensively covers the multisystem disorders that require a multidisciplinary approach, including the cardiological, rheumatological, haematological, infectious, oncological, and urological aspects of kidney disease. In parallel, it extensively describes the myriad multisystem complications of progressive chronic kidney disease with practical advice on how these should be investigated and managed. The importance of understanding the evolution of kidney disease in children and young adults is covered, as in many parts of the world there is no distinction between adult and paediatric nephrology. Therefore, it is important that nephrologists have a sound grasp of both paediatric and adult kidney diseases. The number of patients with advanced kidney disease treated with a kidney transplant or receiving dialysis is increasing in all parts of the world. All nephrologists will manage patients on dialysis or who have a kidney transplant and all internists will encounter these patients. Thus, it is imperative that they have an understanding of these treatments and the commonly encountered medical problems such patients experience.


2021 ◽  
Vol 12 ◽  
Author(s):  
Myriam Dao ◽  
Helene François

Chronic kidney disease (CKD) concerns millions of individuals worldwide, with few therapeutic strategies available to date. Recent evidence suggests that the endocannabinoid system (ECS) could be a new therapeutic target to prevent CKD. ECS combines receptors, cannabinoid receptor type 1 (CB1R) and type 2 (CB2R), and ligands. The most prominent receptor within the kidney is CB1R, its endogenous local ligands being anandamide and 2-arachidonoylglycerol. Therefore, the present review focuses on the therapeutic potential of CB1R and not CB2R. In the normal kidney, CB1R is expressed in many cell types, especially in the vasculature where it contributes to the regulation of renal hemodynamics. CB1R could also participate to water and sodium balance and to blood pressure regulation but its precise role remains to decipher. CB1R promotes renal fibrosis in both metabolic and non-metabolic nephropathies. In metabolic syndrome, obesity and diabetes, CB1R inhibition not only improves metabolic parameters, but also exerts a direct role in preventing renal fibrosis. In non-metabolic nephropathies, its inhibition reduces the development of renal fibrosis. There is a growing interest of the industry to develop new CB1R antagonists without central nervous side-effects. Experimental data on renal fibrosis are encouraging and some molecules are currently under early-stage clinical phases (phases I and IIa studies). In the present review, we will first describe the role of the endocannabinoid receptors, especially CB1R, in renal physiology. We will next explore the role of endocannabinoid receptors in both metabolic and non-metabolic CKD and renal fibrosis. Finally, we will discuss the therapeutic potential of CB1R inhibition using the new pharmacological approaches. Overall, the new pharmacological blockers of CB1R could provide an additional therapeutic toolbox in the management of CKD and renal fibrosis from both metabolic and non-metabolic origin.


2021 ◽  
Author(s):  
Hao Liu ◽  
Chitkale Hiremath ◽  
Quinten Patterson ◽  
Saumya Vora ◽  
Zhiguo Shang ◽  
...  

ABSTRACTBackgroundLymphatic abnormalities are observed in several types of kidney disease, but the relationship between the renal lymphatic system and renal function is unclear. The discovery of lymphatic-specific proteins, advances in microscopy, and available genetic mouse models provide the tools to help elucidate the role of renal lymphatics in physiology and disease.MethodsWe utilized a mouse model containing a missense mutation in Vegfr3 (dubbed Chy) that abrogates its kinase ability. Vegfr3Chy/+ mice were examined for developmental abnormalities and kidney-specific outcomes. Control and Vegfr3Chy/+ mice were subjected to cisplatin-mediated injury. We characterized renal lymphatics using a combination of tissue clearing, light-sheet microscopy and computational analyses.ResultsIn the kidney, we found Vegfr3 is expressed not only in lymphatic vessels, but also various blood vessels. Vegfr3Chy/+ mice had severely reduced renal lymphatics with 100% penetrance, but we found no abnormalities in blood pressure, renal function and histology. Similarly, there was no difference in the degree of renal injury after cisplatin, although Vegfr3Chy/+ mice developed more perivascular inflammation by histology. Control mice treated with cisplatin had a measurable increase in cortical lymphatic density despite no change in cortical lymphatic volume and length.ConclusionsWe demonstrate that Vegfr3 is required for development of renal lymphatics, but a reduction in lymphatic density does not alter renal function and induces only modest histological changes after injury. Our data suggests that an increase in lymphatic density after cisplatin injury may reflect the loss of cortical volume associated with chronic kidney disease rather than growth of lymphatic vessels.SIGNIFICANCE STATEMENTDefects in renal lymphatics occur in various kidney diseases, but their role in maintaining kidney structure and function is unknown. We combine tissue clearing, light-sheet microscopy and computational analysis to characterize lymphatics and find that mice with a heterozygous mutation in Vegfr3 (Vegfr3Chy/+) have severely reduced renal lymphatics. Strikingly, these mice have indistinguishable renal function and histology compared with controls. Even after cisplatin injury, there are no differences in renal function, although Vegfr3Chy/+ mice developed more perivascular inflammation. Our data present a novel method of lymphatic quantification and suggest that a normal complement of renal lymphatics is dispensable for renal structure and function.


2021 ◽  
pp. 1-14
Author(s):  
Yu Sun ◽  
Sijia Cui ◽  
Yunfeng Hou ◽  
Fan Yi

<b><i>Background:</i></b> Podocytes, functionally specialized and terminally differentiated glomerular visceral epithelial cells, are critical for maintaining the structure and function of the glomerular filtration barrier. Podocyte injury is considered as the most important early event contributing to proteinuric kidney diseases such as obesity-related renal disease, diabetic kidney disease, focal segmental glomerulosclerosis, membranous nephropathy, and minimal change disease. Although considerable advances have been made in the understanding of mechanisms that trigger podocyte injury, cell-specific and effective treatments are not clinically available. <b><i>Summary:</i></b> Emerging evidence has indicated that the disorder of podocyte lipid metabolism is closely associated with various proteinuric kidney diseases. Excessive lipid accumulation in podocytes leads to cellular dysfunction which is defined as lipotoxicity, a phenomenon characterized by mitochondrial oxidative stress, actin cytoskeleton remodeling, insulin resistance, and inflammatory response that can eventually result in podocyte hypertrophy, detachment, and death. In this review, we summarize recent advances in the understanding of lipids in podocyte biological function and the regulatory mechanisms leading to podocyte lipid accumulation in proteinuric kidney disease. <b><i>Key Messages:</i></b> Targeting podocyte lipid metabolism may represent a novel therapeutic strategy for patients with proteinuric kidney disease.


2016 ◽  
Vol 14 (1) ◽  
pp. 8-10 ◽  
Author(s):  
Ingrid Prkacin ◽  
Gordana Cavric ◽  
Nikolina Basic-Jukic

AbstractClinical and laboratory findings of kidney disease in an adult may find an explanation in kidney functional and/or structural abnormalities that already existed during infancy and childhood, but that may have been missed or underdiagnosed. All the cardiovascular abnormalities that occur in adults with chronic kidney disease are also present in children with chronic kidney disease. Complications in childhood chronic kidney disease will have consequences well beyond pediatric age and influence outcomes of affected young adults with disease. Kidney dysfunction appears early in the course of kidney disease and has been observed in children and adults with chronic kidney disease, condition characterised with kidney fibrosis. Transforming growth factor beta is recognized as a major mediator of kidney fibrosis. New evidence illustrates the relationship between transforming growth factor beta signaling and microRNAs expression during kidney diseases development. MicroRNAs play important roles in kidney development and kidney diseases; they are naturally occurring, 22-nucleotide, noncoding RNAs that mediate posttranscriptional gene regulation. Dysregulation of miRNA expression is an indicator of several diseases including chronic kidney disease. Targeting microRNAs should be a therapeutic potential to ameliorate the disease related to fibrosis. The discovery that circulating miRNAs are detectable in serum and plasma, and that their expression varies as a result of disease, presents great potential to be used as biomarkers in kidney disease prevention and diagnosis.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Lini Jin ◽  
Binfeng Yu ◽  
Ines Armando ◽  
Fei Han

The integrity and function of mitochondria are essential for normal kidney physiology. Mitochondrial DNA (mtDNA) has been widely a concern in recent years because its abnormalities may result in disruption of aerobic respiration, cellular dysfunction, and even cell death. Particularly, aberrant mtDNA copy number (mtDNA-CN) is associated with the development of acute kidney injury and chronic kidney disease, and urinary mtDNA-CN shows the potential to be a promising indicator for clinical diagnosis and evaluation of kidney function. Several lines of evidence suggest that mtDNA may also trigger innate immunity, leading to kidney inflammation and fibrosis. In mechanism, mtDNA can be released into the cytoplasm under cell stress and recognized by multiple DNA-sensing mechanisms, including Toll-like receptor 9 (TLR9), cytosolic cGAS-stimulator of interferon genes (STING) signaling, and inflammasome activation, which then mediate downstream inflammatory cascades. In this review, we summarize the characteristics of these mtDNA-sensing pathways mediating inflammatory responses and their role in the pathogenesis of acute kidney injury, nondiabetic chronic kidney disease, and diabetic kidney disease. In addition, we highlight targeting of mtDNA-mediated inflammatory pathways as a novel therapeutic target for these kidney diseases.


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