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2.
Sci Rep ; 10(1): 8418, 2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32439965

RESUMO

More effective treatments for diabetic nephropathy remain a major unmet clinical need. Increased oxidative stress is one of the most important pathological mechanisms that lead to kidney damage and functional impairment induced by diabetes. Sirtuin 3 (SIRT3) is the main mitochondrial deacetylase and critically regulates cellular reactive oxygen species (ROS) production and detoxification. Honokiol is a natural biphenolic compound that, by activating mitochondrial SIRT3, can carry out anti-oxidant, anti-inflammatory and anti-fibrotic activities. Here, we sought to investigate the renoprotective effects of honokiol in BTBR ob/ob mice with type 2 diabetes. Diabetic mice were treated with vehicle or honokiol between the ages of 8 and 14 weeks. Wild-type mice served as controls. Renal Sirt3 expression was significantly reduced in BTBR ob/ob mice, and this was associated with a reduction in its activity and increased ROS levels. Selective activation of SIRT3 through honokiol administration translated into the attenuation of albuminuria, amelioration of glomerular damage, and a reduction in podocyte injury. SIRT3 activation preserved mitochondrial wellness through the activation of SOD2 and the restoration of PGC-1α expression in glomerular cells. Additionally, the protective role of SIRT3 in glomerular changes was associated with enhanced tubular Sirt3 expression and upregulated renal Nampt levels, indicating a possible tubule-glomerulus retrograde interplay, which resulted in improved glomerular SIRT3 activity. Our results demonstrate the hitherto unknown renoprotective effect of SIRT3 against diabetic glomerular disease and suggest that the pharmacological modulation of SIRT3 activity is a possible novel approach to treating diabetic nephropathy.

3.
Kidney Int ; 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32461141

RESUMO

The novel coronavirus disease COVID-19 originates in the lungs, but may extend to other organs, causing, in severe cases, multiorgan damage, including cardiac injury and acute kidney injury. In severe cases, the presence of kidney injury is associated with increased risk of death, highlighting the relevance of this organ as a target of SARS-CoV-2 infection. COVID-19-associated tissue injury is not primarily mediated by viral infection, but rather is a result of the inflammatory host immune response, which drives hypercytokinemia and aggressive inflammation that affect lung parenchymal cells, diminishing oxygen uptake but also endothelial cells, resulting in endotheliitis and thrombotic events and intravascular coagulation. The complement system represents the first response of the host immune system to SARS-CoV-2 infection, but there is growing evidence that unrestrained activation of complement induced by the virus in the lungs and other organs plays a major role in acute and chronic inflammation, endothelial cell dysfunction, thrombus formation and intravascular coagulation, and ultimately contributes to multiple organ failure and death. In this review we will discuss the relative role of the different complement activation products in the pathogenesis of COVID-19-associated tissue inflammation and thrombosis and propose the hypothesis that blockade of the terminal complement pathway may represent a potential therapeutic option for the prevention and treatment of lung and multi-organ damage.

5.
JCI Insight ; 5(5)2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32161193

RESUMO

Renal activation of the complement system has been described in patients with diabetic nephropathy (DN), although its pathological relevance is still ill-defined. Here, we studied whether glomerular C3a, generated by uncontrolled complement activation, promotes podocyte damage, leading to proteinuria and renal injury in mice with type 2 diabetes. BTBR ob/ob mice exhibited podocyte loss, albuminuria, and glomerular injury accompanied by C3 deposits and increased C3a and C3a receptor (C3aR) levels. Decreased glomerular nephrin and α-actinin4 expression, coupled with integrin-linked kinase induction, were also observed. Treatment of DN mice with a C3aR antagonist enhanced podocyte density and preserved their phenotype, limiting proteinuria and glomerular injury. Mechanistically, ultrastructural and functional mitochondrial alterations, accompanied by downregulation of antioxidant superoxide dismutase 2 (SOD2) and increased protein oxidation, occurred in podocytes and were normalized by C3aR blockade. In cultured podocytes, C3a induced cAMP-dependent mitochondrial fragmentation. Alterations of mitochondrial membrane potential, SOD2 expression, and energetic metabolism were also found in response to C3a. Notably, C3a-induced podocyte motility was inhibited by SS-31, a peptide with mitochondrial protective effects. These data indicate that C3a blockade represents a potentially novel therapeutic strategy in DN for preserving podocyte integrity through the maintenance of mitochondrial functions.

7.
Nephron ; 144(5): 213-221, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32203970

RESUMO

Here, we review the most recent findings on the effects of SARS-CoV-2 infection on kidney diseases, including acute kidney injury, and examine the potential effects of ARBs on the outcomes of patients with COVID-19. Lastly, we discuss the clinical management of COVID-19 patients with existing chronic renal disorders, particularly those in dialysis and with kidney transplants.


Assuntos
Angiotensinas/antagonistas & inibidores , Infecções por Coronavirus/complicações , Nefropatias/complicações , Nefropatias/tratamento farmacológico , Pneumonia Viral/complicações , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Betacoronavirus/fisiologia , Humanos , Rim/virologia , Transplante de Rim , Nefrologistas , Pandemias , Peptidil Dipeptidase A , Diálise Renal , Replicação Viral
8.
Lancet ; 395(10231): 1225-1228, 2020 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-32178769

RESUMO

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has already taken on pandemic proportions, affecting over 100 countries in a matter of weeks. A global response to prepare health systems worldwide is imperative. Although containment measures in China have reduced new cases by more than 90%, this reduction is not the case elsewhere, and Italy has been particularly affected. There is now grave concern regarding the Italian national health system's capacity to effectively respond to the needs of patients who are infected and require intensive care for SARS-CoV-2 pneumonia. The percentage of patients in intensive care reported daily in Italy between March 1 and March 11, 2020, has consistently been between 9% and 11% of patients who are actively infected. The number of patients infected since Feb 21 in Italy closely follows an exponential trend. If this trend continues for 1 more week, there will be 30 000 infected patients. Intensive care units will then be at maximum capacity; up to 4000 hospital beds will be needed by mid-April, 2020. Our analysis might help political leaders and health authorities to allocate enough resources, including personnel, beds, and intensive care facilities, to manage the situation in the next few days and weeks. If the Italian outbreak follows a similar trend as in Hubei province, China, the number of newly infected patients could start to decrease within 3-4 days, departing from the exponential trend. However, this cannot currently be predicted because of differences between social distancing measures and the capacity to quickly build dedicated facilities in China.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções por Coronavirus/terapia , Feminino , Saúde Global , Política de Saúde/tendências , Número de Leitos em Hospital/estatística & dados numéricos , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Unidades de Terapia Intensiva/provisão & distribução , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Pandemias , Pneumonia Viral/terapia , Respiração Artificial/estatística & dados numéricos
9.
Nephron ; 144(4): 195-203, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32050203

RESUMO

A membranoproliferative pattern of glomerular injury is frequently observed in patients with complement-mediated disorders, such as C3 glomerulopathies (C3G) and primary immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN). The outcomes of C3G and -IC-MPGN are poor, independently of immunosuppressive therapy. However, two 48-week treatment periods with the anti-C5 monoclonal antibody eculizumab, divided by a -12-week washout period, achieved remission of proteinuria and stabilization/improvement of the glomerular filtration rate (GFR), measured through iohexol plasma clearance, in 3 of 10 patients with biopsy-proven MPGN, nephrotic syndrome and terminal complement complex sC5b-9 plasma levels >1,000 mg/mL, at inclusion. Baseline and end-of-study kidney biopsies were available for 2 patients with IC-MPGN, and their baseline characteristics were similar. However, in 1 patient proteinuria and GFR did not improve during the study, whereas in the other proteinuria decreased from 4.84 to 2.12 g/24-h and GFR increased from 91.5 to 142.7 mL/min/1.73 m2. Glomerular inflammation improved and median (interquartile range) glomerular staining for C5b-9 decreased in both cases: from 23.6 to 18.2% (p = 0.021) in the patient who achieved remission and from 15.8 to 10.7% (p = 0.019) in the patient with persistent proteinuria. Chronic glomerular lesions progressed and C3 glomerular staining and electron-dense deposits did not change appreciably in either case. However, in the patient who achieved remission, ultrastructural evaluation revealed features of glomerular microangiopathy at inclusion, which fully recovered posttreatment. Podocyte foot process effacement was observed in both patients at inclusion, but recovered only in the patient with microangiopathy. Thus, in 2 patients with -IC-MPGN, chronic glomerular changes progressed despite eculizumab-induced amelioration of glomerular inflammation and inhibition of sC5b-9 deposition, and independently of treatment effects on proteinuria and podocytes. The finding that the regression of microangiopathic changes was associated with improved clinical outcomes suggests that C5 blockade might have a therapeutic role in patients with IC-MPGN displaying microangiopathic endothelial injury.

10.
BMJ Case Rep ; 13(1)2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31980477

RESUMO

Rituximab (375 mg/m2) achieved remission of the first episode and six relapses of nephrotic syndrome (NS) in a young male patient with podocyte phospholipase A2 receptor (PLA2R)-related membranous nephropathy (MN) refractory to steroids and cyclosporine. Between-treatments interval averaged 17.4±4.2 months. The seventh infusion was complicated by delayed serum-sickness, which resolved with steroids. On subsequent relapse, the fully human anti-CD20 monoclonal antibody ofatumumab (300 mg) achieved remission of the NS, without significant side effects. Circulating CD19+ B cells were depleted, proteinuria decreased from 10.9 to 1.3 g/day, and serum albumin, immunoglobulin levels and glomerular filtration rate normalised. Twenty-eight months later, despite transient anti-PLA2R depletion, ofatumumab (100 mg) failed to induce remission of the eighth relapse. Remission was safely achieved 5 months later with repeated ofatumumab infusion (300 mg). This treatment (€723) was less expensive than rituximab (€1801). Ofatumumab could be a safe and cost/effective rescue therapy for patients with MN sensitised against rituximab.

11.
J Am Soc Nephrol ; 31(3): 517-531, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31988271

RESUMO

BACKGROUND: In donor kidneys subjected to ischemia-reperfusion injury during kidney transplant, phagocytes coexpressing the F4/80 and CD11c molecules mediate proinflammatory responses and trigger adaptive immunity in transplantation through antigen presentation. After injury, however, resident renal macrophages coexpressing these surface markers acquire a proreparative phenotype, which is pivotal in controlling inflammation and fibrosis. No data are currently available regarding the effects of transplant-induced ischemia-reperfusion injury on the ability of donor-derived resident renal macrophages to act as professional antigen-presenting cells. METHODS: We evaluated the phenotype and function of intragraft CD11c+F4/80+ renal macrophages after cold ischemia. We also assessed the modifications of donor renal macrophages after reversible ischemia-reperfusion injury in a mouse model of congeneic renal transplantation. To investigate the role played by IL-1R8, we conducted in vitro and in vivo studies comparing cells and grafts from wild-type and IL-R8-deficient donors. RESULTS: Cold ischemia and reversible ischemia-reperfusion injury dampened antigen presentation by renal macrophages, skewed their polarization toward the M2 phenotype, and increased surface expression of IL-1R8, diminishing activation mediated by toll-like receptor 4. Ischemic IL-1R8-deficient donor renal macrophages acquired an M1 phenotype, effectively induced IFNγ and IL-17 responses, and failed to orchestrate tissue repair, resulting in severe graft fibrosis and aberrant humoral immune responses. CONCLUSIONS: IL-1R8 is a key regulator of donor renal macrophage functions after ischemia-reperfusion injury, crucial to guiding the phenotype and antigen-presenting role of these cells. It may therefore represent an intriguing pathway to explore with respect to modulating responses against autoantigens and alloantigens after kidney transplant.

13.
Curr Opin Organ Transplant ; 25(1): 27-34, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31815791

RESUMO

PURPOSE OF REVIEW: Mesenchymal stromal cells (MSC) have been proposed as a novel cell therapy for immune-mediated diseases, including solid organ transplantation. Here, we provide an overview of recent preclinical and clinical studies in solid organ transplantation using MSC immunomodulatory therapy. RECENT FINDINGS: MSC have been tested successfully in models of corneal and lung transplantation, suggesting that either the programmed cell death protein 1/programmed death ligand 1 pathway or the generation of intermediary immune-regulatory monocyte-macrophage population are the main mechanisms of the protolerogenic effect of MSC. In clinical transplantation, allogeneic MSC from bone marrow or umbilical cord have been evaluated in kidney and lung transplantation with an excellent safety profile. Recent data from kidney transplant patients given autologous bone marrow-MSC enrolled in our phase 1 study demonstrated a good long term safety profile. Extensive immunomonitoring of this initial cohort provided evidence of the development of a protolerogenic environment in some MSC-treated patients. One of these patients has been weaned off immunosuppression successfully. SUMMARY: The available clinical studies in kidney, liver and lung transplantation indicate that autologous and allogeneic MSC therapy from different sources are safe. Now it's time to focus on well-designed efficacy clinical trials, possibly including extensive immunomonitoring.

14.
Nephron ; 144(1): 38-48, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31550726

RESUMO

BACKGROUND: Tissue fibrosis is the final common phase of chronic allograft injury, the leading cause of late graft loss in kidney transplantation. Preclinical evidence points to the involvement of lysophosphatidic acid (LPA), a bioactive phospholipid, in the development of renal fibrosis. OBJECTIVES: We assessed whether treatment with an orally available inhibitor of autotaxin (ATXi), the main LPA-producing enzyme, could slow the progression of chronic allograft injury in a fully major histocompatibility complex-mismatched rat kidney transplant model and compared its effects with those of the angiotensin-converting enzyme inhibitor lisinopril. METHODS: Kidney allograft recipients were given ciclosporin for the first 15 postoperative days to prevent early acute rejection. Thereafter, they received either no treatment or ATXi or lisinopril and were followed for 180 days after transplantation. RESULTS: Renal LPA levels were increased in allograft rats, providing the rationale for using ATXi in this model. Chronic treatment with ATXi or lisinopril limited progressive proteinuria and ameliorated tubulointerstitial fibrosis compared with allograft rats, although the effects were more robust under ATX inhibition. The administration of ATXi, but not lisinopril, attenuated systemic hypertension, reduced intragraft T cell infiltration, and eventually improved renal graft survival. CONCLUSIONS: In summary, ATXi had protective effects on indices of chronic allograft injury and could be of therapeutic add-on value in the kidney transplant setting. Notably, an ATX inhibitor is currently being investigated in 2 large phase 3 studies in idiopathic pulmonary fibrosis, underscoring the clinical relevance of our findings.

15.
Nephron ; 144(1): 30-35, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31336376

RESUMO

Patients with membranous nephropathy (MN) and persistent nephrotic syndrome (NS) are at increased risk of -progression to end-stage renal disease. The discovery of -autoantibodies against the podocyte-expressed M-type phospholipase A2 receptor (PLA2R) provided a clear pathophysiological rationale for interventions targeting the B-cell lineage to prevent antibody production and subepithelial immune-complex deposition. The anti-CD20 monoclonal antibodies, rituximab and ofatumumab, are safe and achieve remission of NS in approximately two-thirds of patients with MN. In patients with PLA2R-related MN, remission can be predicted by anti-PLA2R antibody depletion, and faster depletion is associated with earlier reduction of proteinuria and improved nephroprotection. Selective apheresis methods, such as double-filtration plasmapheresis (DFPP), may accelerate the clearance of autoreactive antibodies and at the same time avoid the side effects of plasma-exchange. In this preliminary, explorative, proof-of-concept study, we observed that in patients with PLA2R-related MN, NS and high antibody levels, ofatumumab-induced B-cell depletion followed by DFPP accelerated anti-PLA2R depletion compared to anti-CD20 monotherapy. This therapeutic regimen was safe and well tolerated. These observations may provide the background for controlled trials aimed at formally testing whether the addition of DFPP to anti-CD20 therapy could offer a novel therapeutic option, especially for patients with more severe MN.

16.
Stem Cells Transl Med ; 9(4): 427-432, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31872574

RESUMO

Here we report the case of successful immune tolerance induction in a living-donor kidney transplant recipient remotely treated with autologous bone marrow-derived mesenchymal stromal cells (MSC). This case report, which to the best of our knowledge is the first in the world in this setting, provides evidence that the modulation of the host immune system with MSC can enable the safe withdrawal of maintenance immunosuppressive drugs while preserving optimal long-term kidney allograft function.

19.
JCI Insight ; 4(18)2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31534055

RESUMO

Thyroid hormone (TH) signaling is a universal regulator of metabolism, growth, and development. Here, we show that TH-TH receptor (TH-TR) axis alterations are critically involved in diabetic nephropathy-associated (DN-associated) podocyte pathology, and we identify TRα1 as a key regulator of the pathogenesis of DN. In ZSF1 diabetic rats, T3 levels progressively decreased during DN, and this was inversely correlated with metabolic and renal disease worsening. These phenomena were associated with the reexpression of the fetal isoform TRα1 in podocytes and parietal cells of both rats and patients with DN and with the increased glomerular expression of the TH-inactivating enzyme deiodinase 3 (DIO3). In diabetic rats, TRα1-positive cells also reexpressed several fetal mesenchymal and damage-related podocyte markers, while glomerular and podocyte hypertrophy was evident. In vitro, exposing human podocytes to diabetes milieu typical components markedly increased TRα1 and DIO3 expression and induced cytoskeleton rearrangements, adult podocyte marker downregulation and fetal kidney marker upregulation, the maladaptive cell cycle induction/arrest, and TRα1-ERK1/2-mediated hypertrophy. Strikingly, T3 treatment reduced TRα1 and DIO3 expression and completely reversed all these alterations. Our data show that diabetic stress induces the TH-TRα1 axis to adopt a fetal ligand/receptor relationship pattern that triggers the recapitulation of the fetal podocyte phenotype and subsequent pathological alterations.

20.
BMJ Open ; 9(9): e031169, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31551387

RESUMO

INTRODUCTION: A recently recognised form of chronic kidney disease (CKD) of unknown origin (CKDu) is afflicting communities, mostly in rural areas in several regions of the world. Prevalence studies are being conducted in a number of countries, using a standardised protocol, to estimate the distribution of estimated glomerular filtration rate (eGFR), and thus identify communities with a high prevalence of reduced glomerular filtration rate (GFR). In this paper, we propose a standardised minimum protocol for cohort studies in high-risk communities aimed at investigating the incidence of, and risk factors for, early kidney dysfunction. METHODS AND ANALYSIS: This generic cohort protocol provides the information to establish a prospective population-based cohort study in low-income settings with a high prevalence of CKDu. This involves a baseline survey that included key elements from the DEGREE survey (eg, using the previously published DEGREE methodology) of a population-representative sample, and subsequent follow-up visits in young adults (without a pre-existing diagnosis of CKD (eGFR<60 mL/min/1.73m2), proteinuria or risk factors for CKD at baseline) over several years. Each visit involves a core questionnaire, and collection and storage of biological samples. Local capacity to measure serum creatinine will be required so that immediate feedback on kidney function can be provided to participants. After completion of follow-up, repeat measures of creatinine should be conducted in a central laboratory, using reference standards traceable to isotope dilution mass spectrometry (IDMS) quality control material to quantify the main outcome of eGFR decline over time, alongside a description of the early evolution of disease and risk factors for eGFR decline. ETHICS AND DISSEMINATION: Ethical approval will be obtained by local researchers, and participants will provide informed consent before the study commences. Participants will typically receive feedback and advice on their laboratory results, and referral to a local health system where appropriate.

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