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Nature Communications Sep 2023Reninomas are exceedingly rare renin-secreting kidney tumours that derive from juxtaglomerular cells, specialised smooth muscle cells that reside at the vascular inlet...
Reninomas are exceedingly rare renin-secreting kidney tumours that derive from juxtaglomerular cells, specialised smooth muscle cells that reside at the vascular inlet of glomeruli. They are the central component of the juxtaglomerular apparatus which controls systemic blood pressure through the secretion of renin. We assess somatic changes in reninoma and find structural variants that generate canonical activating rearrangements of, NOTCH1 whilst removing its negative regulator, NRARP. Accordingly, in single reninoma nuclei we observe excessive renin and NOTCH1 signalling mRNAs, with a concomitant non-excess of NRARP expression. Re-analysis of previously published reninoma bulk transcriptomes further corroborates our observation of dysregulated Notch pathway signalling in reninoma. Our findings reveal NOTCH1 rearrangements in reninoma, therapeutically targetable through existing NOTCH1 inhibitors, and indicate that unscheduled Notch signalling may be a disease-defining feature of reninoma.
Topics: Humans; Renin; Kidney Neoplasms; Juxtaglomerular Apparatus; Kidney Glomerulus; Signal Transduction; Receptor, Notch1
PubMed: 37749094
DOI: 10.1038/s41467-023-41118-8 -
High Blood Pressure & Cardiovascular... Sep 2017Renin is the first and rate-limiting step of the renin-angiotensin system. The exclusive source of renin in the circulation are the juxtaglomerular cells of the kidney,... (Review)
Review
Renin is the first and rate-limiting step of the renin-angiotensin system. The exclusive source of renin in the circulation are the juxtaglomerular cells of the kidney, which line the afferent arterioles at the entrance of the glomeruli. Normally, renin production by these cells suffices to maintain homeostasis. However, under chronic stimulation of renin release, for instance during a low-salt diet or antihypertensive therapy, cells that previously expressed renin during congenital life re-convert to a renin-producing cell phenotype, a phenomenon which is known as "recruitment". How exactly such differentiation occurs remains to be clarified. This review critically discusses the phenotypic plasticity of renin cells, connecting them not only to the classical concept of blood pressure regulation, but also to more complex contexts such as development and growth processes, cell repair mechanisms and tissue regeneration.
Topics: Animals; Calcium Signaling; Cardiovascular Diseases; Cell Plasticity; Cyclic AMP; Cyclic GMP; Embryonic Stem Cells; Epigenesis, Genetic; Humans; Juxtaglomerular Apparatus; Kidney Diseases; Phenotype; Regeneration; Renin-Angiotensin System; Second Messenger Systems
PubMed: 28527017
DOI: 10.1007/s40292-017-0212-5 -
Seminars in Arthritis and Rheumatism Jun 2015To discuss the pathophysiology, risk factors, clinical manifestations, diagnosis, treatment, prevention, and outcomes of scleroderma renal crisis (SRC), a serious yet... (Review)
Review
OBJECTIVES
To discuss the pathophysiology, risk factors, clinical manifestations, diagnosis, treatment, prevention, and outcomes of scleroderma renal crisis (SRC), a serious yet potentially treatable complication of scleroderma (systemic sclerosis).
METHODS
A PubMed search for articles published up until April 2014 was conducted using the following keywords: scleroderma, systemic sclerosis, scleroderma renal crisis, renal, treatment, and prognosis. Literature was carefully reviewed, and different risk factors, treatment options, prognostic factors, and survival data were assessed.
RESULTS
SRC occurs in about 10% of all patients with scleroderma. It is characterized by malignant hypertension and progressive renal failure. Around 10% of SRC cases may present with normal blood pressure, termed normotensive renal crisis. The etiopathogenesis is presumed to be a series of insults to the kidneys resulting in endothelial injury, intimal proliferation, and narrowing of renal arterioles leading to decreased blood flow, hyperplasia of the juxtaglomerular apparatus, hyperreninemia, and accelerated hypertension. Risk factors include rapid skin thickening, use of certain medications such corticosteroids or cyclosporine, new-onset microangiopathic hemolytic anemia and/or thrombocytopenia, cardiac complications (pericardial effusion, congestive heart failure, and/or arrhythmias), large joint contractures, and presence of anti-RNA polymerase III antibody. Since the 1970s, with the advent of angiotensin-converting enzyme (ACE) inhibitors, mortality associated with SRC decreased from 76% to <10%. Some patients may progress to end-stage renal disease and need dialysis. Renal transplantation has improved survival, though SRC may recur in transplanted kidneys.
CONCLUSIONS
More than 60 years after its initial description, SRC still remains an important cause of morbidity and mortality in scleroderma. Since the advent of ACE inhibitors, the prognosis of SRC has improved substantially. Prompt diagnosis and treatment may help prevent adverse outcomes and improve survival.
Topics: Angiotensin-Converting Enzyme Inhibitors; Disease Progression; Humans; Hypertension, Malignant; Prognosis; Renal Dialysis; Renal Insufficiency; Risk Factors; Scleroderma, Systemic
PubMed: 25613774
DOI: 10.1016/j.semarthrit.2014.12.001 -
European Endocrinology Oct 2020Therapeutic advances have revolutionised cancer treatment over the last two decades, but despite improved survival and outcomes, adverse effects to anticancer therapy... (Review)
Review
Therapeutic advances have revolutionised cancer treatment over the last two decades, but despite improved survival and outcomes, adverse effects to anticancer therapy such as dyselectrolytaemias do occur and need to be managed appropriately. This review explores essential aspects of sodium homeostasis in cancer with a focus on alterations arising from anticancer medications. Sodium and water balance are tightly regulated by close interplay of stimuli arising from hypothalamic osmoreceptors, arterial and atrial baroreceptors and the renal juxtaglomerular apparatus. This delicate balance can be disrupted by cancer itself, as well as the medications used to treat it. Some of the conventional chemotherapeutics, such as alkylating agents and platinum-based drugs, can cause hyponatraemia and, on rare occasions, hypernatraemia. Other conventional agents such as vinca alkaloids, as well as newer targeted cancer therapies including small molecule inhibitors and monoclonal antibodies, can cause hyponatraemia, usually as a result of inappropriate antidiuretic hormone secretion. Hyponatraemia can also sometimes occur secondarily to drug-induced hypocortisolism or salt-wasting syndromes. Another atypical but distinct mechanism for hyponatraemia is via pituitary dysfunction induced by immune checkpoint inhibitors. Hypernatraemia is uncommon and occasionally ensues as a result of drug-induced nephrogenic diabetes insipidus. Identification of the aetiology and appropriate management of these conditions, in addition to averting treatment-related problems, can be lifesaving in critical situations.
PubMed: 33117443
DOI: 10.17925/EE.2020.16.2.122 -
Circulation Research Apr 2021Renin cells are essential for survival perfected throughout evolution to ensure normal development and defend the organism against a variety of homeostatic threats.... (Review)
Review
Renin cells are essential for survival perfected throughout evolution to ensure normal development and defend the organism against a variety of homeostatic threats. During embryonic and early postnatal life, they are progenitors that participate in the morphogenesis of the renal arterial tree. In adult life, they are capable of regenerating injured glomeruli, control blood pressure, fluid-electrolyte balance, tissue perfusion, and in turn, the delivery of oxygen and nutrients to cells. Throughout life, renin cell descendants retain the plasticity or memory to regain the renin phenotype when homeostasis is threatened. To perform all of these functions and maintain well-being, renin cells must regulate their identity and fate. Here, we review the major mechanisms that control the differentiation and fate of renin cells, the chromatin events that control the memory of the renin phenotype, and the major pathways that determine their plasticity. We also examine how chronic stimulation of renin cells alters their fate leading to the development of a severe and concentric hypertrophy of the intrarenal arteries and arterioles. Lastly, we provide examples of additional changes in renin cell fate that contribute to equally severe kidney disorders.
Topics: Animals; Arterioles; Blood Pressure; Cell Communication; Cell Differentiation; Cell Plasticity; Chromatin; Chromatin Assembly and Disassembly; Connexins; Homeostasis; Humans; Hypertension; Integrins; Juxtaglomerular Apparatus; Kidney; Kidney Glomerulus; Mice; MicroRNAs; Phenotype; Regeneration; Renal Artery; Renin; Renin-Angiotensin System; Stem Cells; Water-Electrolyte Balance
PubMed: 33793334
DOI: 10.1161/CIRCRESAHA.121.318064 -
Acta Physiologica (Oxford, England) Nov 2023This review outlines the features of tandem regulation of glomerular microcirculation by autoregulatory mechanisms and intraglomerular redistribution of blood flow.... (Review)
Review
This review outlines the features of tandem regulation of glomerular microcirculation by autoregulatory mechanisms and intraglomerular redistribution of blood flow. Multiple points of cooperation exist between autoregulatory and distributional mechanisms. Mutual interactions between myogenic and tubuloglomerular feedback (TGF) mechanisms regulating the inflow are briefly discussed. In addition to this, TGF operation involving purinergic, autocoid, and NO signaling affects, however, not only afferent arteriolar tone, but mesangial cell tone as well. The latter reversibly reconfigures the distribution of blood flow between the shorter and longer pathways in the glomerular tuft. I advance a hypothesis that blood flow in these pathways spontaneously alternates, and mesangial cell tonicity serves as a rheostatic shift between them. Furthermore, humoral messengers from macula densa cells, themselves dependent on myogenic mechanisms, fine-tune the secretion of renin and, subsequently, the local, intrarenal generation of angiotensin II, which, in turn, provides additional vasomotor signaling to glomerular capillaries through changing the tone of mesangial cells. This complex regulatory network may partially explain the phenomenon of renal functional reserve, as well as suggest implications for changes in renal function during pregnancy, early diabetes mellitus, and acute kidney injury.
Topics: Female; Humans; Pre-Eclampsia; Microcirculation; Kidney; Kidney Glomerulus; Diabetes Mellitus; Kidney Diseases
PubMed: 37688412
DOI: 10.1111/apha.14048 -
Pflugers Archiv : European Journal of... Aug 2022The protease renin, the key enzyme of the renin-angiotensin-aldosterone system, is mainly produced and secreted by juxtaglomerular cells in the kidney, which are located... (Review)
Review
The protease renin, the key enzyme of the renin-angiotensin-aldosterone system, is mainly produced and secreted by juxtaglomerular cells in the kidney, which are located in the walls of the afferent arterioles at their entrance into the glomeruli. When the body's demand for renin rises, the renin production capacity of the kidneys commonly increases by induction of renin expression in vascular smooth muscle cells and in extraglomerular mesangial cells. These cells undergo a reversible metaplastic cellular transformation in order to produce renin. Juxtaglomerular cells of the renin lineage have also been described to migrate into the glomerulus and differentiate into podocytes, epithelial cells or mesangial cells to restore damaged cells in states of glomerular disease. More recently, it could be shown that renin cells can also undergo an endocrine and metaplastic switch to erythropoietin-producing cells. This review aims to describe the high degree of plasticity of renin-producing cells of the kidneys and to analyze the underlying mechanisms.
Topics: Cell Differentiation; Juxtaglomerular Apparatus; Kidney; Kidney Glomerulus; Mesangial Cells; Myocytes, Smooth Muscle; Podocytes; Renin; Renin-Angiotensin System
PubMed: 35511367
DOI: 10.1007/s00424-022-02694-8 -
The Canadian Journal of Cardiology May 2018Hypertension is highly prevalent among people with diabetes, and the presence of diabetes among those with hypertension portends an increase in cardiovascular risk. In... (Review)
Review
Hypertension is highly prevalent among people with diabetes, and the presence of diabetes among those with hypertension portends an increase in cardiovascular risk. In this review we aim to explore the pathophysiological links between diabetes and hypertension. Renal sodium handling differs in diabetes because there is an upregulation of sodium transporters in the kidneys. The renin-angiotensin-aldosterone system may be upregulated in diabetes, leading to hypertension through a direct effect mediated by angiotensin II, as well as indirectly through upregulation of sympathetic activity. Renin-angiotensin-aldosterone system blockade is a mainstay therapy for hypertension, and evidence suggests that it might also reduce the incidence of diabetes. People with diabetes frequently have autonomic dysfunction, which could contribute to hypertension through increased sympathetic tone and through stimulation of renin production in the juxtaglomerular apparatus. Furthermore, people with diabetes also frequently show an abnormality in their circadian blood pressure pattern. Another important link between hypertension and diabetes is the development as well as progression of diabetic kidney disease, the pathophysiology of which is mediated through several pathways including endothelial dysfunction and advanced glycation end products. Finally, obesity and the metabolic syndrome, through their effects on various hormones and inflammation, might also contribute to the pathogenesis of hypertension and diabetes.
Topics: Blood Pressure; Diabetes Mellitus; Humans; Hypertension; Metabolism; Renin-Angiotensin System; Sympathetic Nervous System
PubMed: 29731021
DOI: 10.1016/j.cjca.2018.01.010