scholarly journals From Proteinuria to Fibrosis: An Update on Pathophysiology and Treatment Options

2021 ◽  
pp. 1-10
Author(s):  
Sonia Sharma ◽  
Brendan Smyth

<b><i>Background:</i></b> Proteinuria is a key biomarker in nephrology. It is central to diagnosis and risk assessment and the primary target of many important therapies. Etiologies resulting in pathological proteinuria include congenital and acquired disorders, as well as both glomerular (immune/non-immune mediated) and tubular defects. <b><i>Summary:</i></b> Untreated proteinuria is strongly linked to progressive loss of kidney function and kidney failure. Excess protein reaching the renal tubules is ordinarily resorbed by the tubular epithelium. However, when these mechanisms are overwhelmed, a variety of inflammatory and fibrotic pathways are activated, causing both interstitial fibrosis and glomerulosclerosis. Nevertheless, the specific mechanisms underlying this are complex and remain incompletely understood. Recently, a number of treatments, in addition to angiotensin system blockade, have been shown to effectively slow the progression of proteinuric chronic kidney disease. However, additional therapies are clearly needed. <b><i>Key message:</i></b> This review provides an update on the pathophysiology of proteinuria, the pathways leading to fibrosis, and an overview of current and emerging therapies.

2013 ◽  
Vol 305 (10) ◽  
pp. F1391-F1401 ◽  
Author(s):  
Andrew J. Kassianos ◽  
Xiangju Wang ◽  
Sandeep Sampangi ◽  
Kimberly Muczynski ◽  
Helen Healy ◽  
...  

Dendritic cells (DCs) play critical roles in immune-mediated kidney diseases. Little is known, however, about DC subsets in human chronic kidney disease, with previous studies restricted to a limited set of pathologies and to using immunohistochemical methods. In this study, we developed novel protocols for extracting renal DC subsets from diseased human kidneys and identified, enumerated, and phenotyped them by multicolor flow cytometry. We detected significantly greater numbers of total DCs as well as CD141hi and CD1c+ myeloid DC (mDCs) subsets in diseased biopsies with interstitial fibrosis than diseased biopsies without fibrosis or healthy kidney tissue. In contrast, plasmacytoid DC numbers were significantly higher in the fibrotic group compared with healthy tissue only. Numbers of all DC subsets correlated with loss of kidney function, recorded as estimated glomerular filtration rate. CD141hi DCs expressed C-type lectin domain family 9 member A (CLEC9A), whereas the majority of CD1c+ DCs lacked the expression of CD1a and DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN), suggesting these mDC subsets may be circulating CD141hi and CD1c+ blood DCs infiltrating kidney tissue. Our analysis revealed CLEC9A+ and CD1c+ cells were restricted to the tubulointerstitium. Notably, DC expression of the costimulatory and maturation molecule CD86 was significantly increased in both diseased cohorts compared with healthy tissue. Transforming growth factor-β levels in dissociated tissue supernatants were significantly elevated in diseased biopsies with fibrosis compared with nonfibrotic biopsies, with mDCs identified as a major source of this profibrotic cytokine. Collectively, our data indicate that activated mDC subsets, likely recruited into the tubulointerstitium, are positioned to play a role in the development of fibrosis and, thus, progression to chronic kidney disease.


2018 ◽  
Vol 90 (10) ◽  
pp. 94-98
Author(s):  
V V Klimontov ◽  
A I Korbut

Urinary albumin excretion (UAE) is widely used in clinical practice as indicator of diabetic kidney disease. According to the classical concept of the natural course of diabetic nephropathy, an increase in UAE usually precedes a decline in renal function. Meanwhile, a growing body of evidences indicates a high prevalence of normoalbuminuric chronic kidney disease (NA-CKD) in diabetic subjects, especially among patients with type 2 diabetes. An increase in NA-CKD prevalence can be results of improved glucose, blood pressure, and lipid control, widespread use of renin-angiotensin system blockers, and smoking cessation. It was shown that NA-CKD is more prevalent among women and is associated with arterial hypertension and coronary artery disease. The renal structure in subjects with NA-CKD is more heterogeneous when compared to patients with increased albuminuria, wherein interstitial changes and arteriolosclerosis could be the principal morphological findings, while signs of glomerulopathy may be absent. The prognostic value of NA-CKD needs to be clarified. It was shown that NA-CKD increases the risk of myocardial infarction, stroke and cardiovascular death in patients with diabetes. The search for alternative diagnostic markers for detecting of diabetic kidney disease in the absence of albuminuria, is of practical importance. The evaluations of the markers of tubular damage and interstitial fibrosis, as well as proteomic approaches, are considered as perspective diagnostic and prognostic options in NA-CKD. The study of pathogenesis, pathology, clinical course of NA-CKD in diabetic patients, as well as the development of more specific diagnostic and treatment options is a challenge for future research.


2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Bohan Chen ◽  
Pei Wang ◽  
Xianhui Liang ◽  
Chunming Jiang ◽  
Yan Ge ◽  
...  

AbstractRenal tubular epithelial cells (TECs) play a key role in renal fibrogenesis. After persistent injuries that are beyond self-healing capacity, TECs will dedifferentiate, undergo growth arrest, convert to profibrogenic phenotypes, and resort to maladaptive plasticity that ultimately results in renal fibrosis. Evidence suggests that glycogen synthase kinase (GSK) 3β is centrally implicated in kidney injury. However, its role in renal fibrogenesis is obscure. Analysis of publicly available kidney transcriptome database demonstrated that patients with progressive chronic kidney disease (CKD) exhibited GSK3β overexpression in renal tubulointerstitium, in which the predefined hallmark gene sets implicated in fibrogenesis were remarkably enriched. In vitro, TGF-β1 treatment augmented GSK3β expression in TECs, concomitant with dedifferentiation, cell cycle arrest at G2/M phase, excessive accumulation of extracellular matrix, and overproduction of profibrotic cytokines like PAI-1 and CTGF. All these profibrogenic phenotypes were largely abrogated by GSK3β inhibitors or by ectopic expression of a dominant-negative mutant of GSK3β but reinforced in cells expressing the constitutively active mutant of GSK3β. Mechanistically, GSK3β suppressed, whereas inhibiting GSK3β facilitated, the activity of cAMP response element-binding protein (CREB), which competes for CREB-binding protein, a transcriptional coactivator essential for TGF-β1/Smad signaling pathway to drive TECs profibrogenic plasticity. In vivo, in mice with folic acid-induced progressive CKD, targeting of GSK3β in renal tubules via genetic ablation or by microdose lithium mitigated the profibrogenic plasticity of TEC, concomitant with attenuated interstitial fibrosis and tubular atrophy. Collectively, GSK3β is likely a pragmatic therapeutic target for averting profibrogenic plasticity of TECs and improving renal fibrosis.


2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Huai Leng Pisaniello ◽  
Mark C. Fisher ◽  
Hamish Farquhar ◽  
Ana Beatriz Vargas-Santos ◽  
Catherine L. Hill ◽  
...  

AbstractGout flare prophylaxis and therapy use in people with underlying chronic kidney disease (CKD) is challenging, given limited treatment options and risk of worsening renal function with inappropriate treatment dosing. This literature review aimed to describe the current literature on the efficacy and safety of gout flare prophylaxis and therapy use in people with CKD stages 3–5. A literature search via PubMed, the Cochrane Library, and EMBASE was performed from 1 January 1959 to 31 January 2018. Inclusion criteria were studies with people with gout and renal impairment (i.e. estimated glomerular filtration rate (eGFR) or creatinine clearance (CrCl) < 60 ml/min/1.73 m2), and with exposure to colchicine, interleukin-1 inhibitors, non-steroidal anti-inflammatory drugs (NSAIDs), and glucocorticoids. All study designs were included. A total of 33 studies with efficacy and/or safety analysis stratified by renal function were reviewed—colchicine (n = 20), anakinra (n = 7), canakinumab (n = 1), NSAIDs (n = 3), and glucocorticoids (n = 2). A total of 58 studies reported these primary outcomes without renal function stratification—colchicine (n = 29), anakinra (n = 10), canakinumab (n = 6), rilonacept (n = 2), NSAIDs (n = 1), and glucocorticoids (n = 10). Most clinical trials excluded study participants with severe CKD (i.e. eGFR or CrCl of < 30 mL/min/1.73 m2). Information on the efficacy and safety outcomes of gout flare prophylaxis and therapy use stratified by renal function is lacking. Clinical trial results cannot be extrapolated for those with advanced CKD. Where possible, current and future gout flare studies should include patients with CKD and with study outcomes reported based on renal function and using standardised gout flare definition.


Author(s):  
Dominique M. Bovée ◽  
Lodi C. W. Roksnoer ◽  
Cornelis van Kooten ◽  
Joris I. Rotmans ◽  
Liffert Vogt ◽  
...  

Abstract Background Acidosis-induced kidney injury is mediated by the intrarenal renin-angiotensin system, for which urinary renin is a potential marker. Therefore, we hypothesized that sodium bicarbonate supplementation reduces urinary renin excretion in patients with chronic kidney disease (CKD) and metabolic acidosis. Methods Patients with CKD stage G4 and plasma bicarbonate 15–24 mmol/l were randomized to receive sodium bicarbonate (3 × 1000 mg/day, ~ 0.5 mEq/kg), sodium chloride (2 × 1,00 mg/day), or no treatment for 4 weeks (n = 15/arm). The effects on urinary renin excretion (primary outcome), other plasma and urine parameters of the renin-angiotensin system, endothelin-1, and proteinuria were analyzed. Results Forty-five patients were included (62 ± 15 years, eGFR 21 ± 5 ml/min/1.73m2, plasma bicarbonate 21.7 ± 3.3 mmol/l). Sodium bicarbonate supplementation increased plasma bicarbonate (20.8 to 23.8 mmol/l) and reduced urinary ammonium excretion (15 to 8 mmol/day, both P < 0.05). Furthermore, a trend towards lower plasma aldosterone (291 to 204 ng/L, P = 0.07) and potassium (5.1 to 4.8 mmol/l, P = 0.06) was observed in patients receiving sodium bicarbonate. Sodium bicarbonate did not significantly change the urinary excretion of renin, angiotensinogen, aldosterone, endothelin-1, albumin, or α1-microglobulin. Sodium chloride supplementation reduced plasma renin (166 to 122 ng/L), and increased the urinary excretions of angiotensinogen, albumin, and α1-microglobulin (all P < 0.05). Conclusions Despite correction of acidosis and reduction in urinary ammonium excretion, sodium bicarbonate supplementation did not improve urinary markers of the renin-angiotensin system, endothelin-1, or proteinuria. Possible explanations include bicarbonate dose, short treatment time, or the inability of urinary renin to reflect intrarenal renin-angiotensin system activity. Graphic abstract


Author(s):  
Natalia Nowak ◽  
Masayuki Yamanouchi ◽  
Eiichiro Satake

AbstractExtracellular vesicle (EV)-based therapy was hypothesized as a promising regenerative approach which has led to intensive research of EVs in various pathologies. In this study, we performed a comprehensive systematic review of the current experimental evidence regarding the protective properties of EVs in chronic kidney disease (CKD). We evaluated the EV-based experiments, EV characteristics, and effector molecules with their involvement in CKD pathways. Including all animal records with available creatinine or urea data, we performed a stratified univariable meta-analysis to assess the determinants of EV-based therapy effectiveness. We identified 35 interventional studies that assessed nephroprotective role of EVs and catalogued them according to their involvement in CKD mechanism. Systematic assessment of these studies suggested that EVs had consistently improved glomerulosclerosis, interstitial fibrosis, and cell damage, among different CKD models. Moreover, EV-based therapy reduced the progression of renal decline in CKD. The stratified analyses showed that the disease model, administered dose, and time of therapeutic intervention were potential predictors of therapeutic efficacy. Together, EV therapy is a promising approach for CKD progression in experimental studies. Further standardisation of EV-methods, continuous improvement of the study quality, and better understanding of the determinants of EV effectiveness will facilitate preclinical research, and may help development of clinical trials in people with CKD. Graphical Abstract


2020 ◽  
Vol 22 (1) ◽  
pp. 350
Author(s):  
Florian Juszczak ◽  
Maud Vlassembrouck ◽  
Olivia Botton ◽  
Thomas Zwakhals ◽  
Morgane Decarnoncle ◽  
...  

Exercise training is now recognized as an interesting therapeutic strategy in managing obesity and its related disorders. However, there is still a lack of knowledge about its impact on obesity-induced chronic kidney disease (CKD). Here, we investigated the effects of a delayed protocol of endurance exercise training (EET) as well as the underlying mechanism in obese mice presenting CKD. Mice fed a high-fat diet (HFD) or a low-fat diet (LFD) for 12 weeks were subsequently submitted to an 8-weeks EET protocol. Delayed treatment with EET in obese mice prevented body weight gain associated with a reduced calorie intake. EET intervention counteracted obesity-related disorders including glucose intolerance, insulin resistance, dyslipidaemia and hepatic steatosis. Moreover, our data demonstrated for the first time the beneficial effects of EET on obesity-induced CKD as evidenced by an improvement of obesity-related glomerulopathy, tubulo-interstitial fibrosis, inflammation and oxidative stress. EET also prevented renal lipid depositions in the proximal tubule. These results were associated with an improvement of the AMPK pathway by EET in renal tissue. AMPK-mediated phosphorylation of ACC and ULK-1 were particularly enhanced leading to increased fatty acid oxidation and autophagy improvement with EET in obese mice.


2002 ◽  
Vol 36 (3) ◽  
pp. 489-503 ◽  
Author(s):  
William E Dager ◽  
Richard H White

OBJECTIVE: To describe heparin-induced thrombocytopenia (HIT or HIT-2), an immune-mediated adverse reaction to heparin or low-molecular-weight heparin. Available treatment options and considerations in developing a therapy approach are discussed. DATA SOURCES: A search of the National Library of Medicine (1992–June 2001) was done to identify pertinent literature. Additional references were reviewed from selected articles. STUDY SELECTION: Articles related to laboratory recognition and treatment options of HIT, including the use of agents in selected clinical conditions, were reviewed and included. CONCLUSIONS: HIT is a rare but potentially severe adverse reaction to heparin that was, until recently, poorly understood and had limited treatment options. Recent advances describing the recognition and clinical manifestations of immune-mediated HIT, including recently available antithrombotic treatment options, have dramatically changed outcomes for patients having this syndrome.


TH Open ◽  
2020 ◽  
Vol 04 (02) ◽  
pp. e138-e144 ◽  
Author(s):  
Wolfgang Miesbach

AbstractThe activated renin–angiotensin system induces a prothrombotic state resulting from the imbalance between coagulation and fibrinolysis. Angiotensin II is the central effector molecule of the activated renin–angiotensin system and is degraded by the angiotensin-converting enzyme 2 to angiotensin (1–7). The novel coronavirus infection (classified as COVID-19) is caused by the new coronavirus SARS-CoV-2 and is characterized by an exaggerated inflammatory response that can lead to severe manifestations such as acute respiratory distress syndrome, sepsis, and death in a proportion of patients, mostly elderly patients with preexisting comorbidities. SARS-CoV-2 uses the angiotensin-converting enzyme 2 receptor to enter the target cells, resulting in activation of the renin–angiotensin system. After downregulating the angiotensin-converting enzyme 2, the vasoconstrictor angiotensin II is increasingly produced and its counterregulating molecules angiotensin (1–7) reduced. Angiotensin II increases thrombin formation and impairs fibrinolysis. Elevated levels were strongly associated with viral load and lung injury in patients with severe COVID-19. Therefore, the complex clinical picture of patients with severe complications of COVID-19 is triggered by the various effects of highly expressed angiotensin II on vasculopathy, coagulopathy, and inflammation. Future treatment options should focus on blocking the thrombogenic and inflammatory properties of angiotensin II in COVID-19 patients.


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