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1.
J Clin Invest ; 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38842935

RESUMO

Proliferative glomerulonephritis is a severe condition often leading to kidney failure. There is a significant lack of effective treatment for these disorders. Here, following the identification of a somatic PIK3CA gain-of-function mutation in podocytes of a patient, we demonstrate using multiple genetically engineered mouse models, single-cell RNA sequencing and spatial transcriptomics the crucial role played by this pathway for proliferative glomerulonephritis development by promoting podocyte proliferation, dedifferentiation and inflammation. Additionally, we show that alpelisib, a PI3Kα inhibitor, improves glomerular lesions and kidney function in different mouse models of proliferative glomerulonephritis and lupus nephritis by targeting podocytes. Surprisingly, we determined that pharmacological inhibition of PI3Kα affects B and T lymphocyte population in lupus nephritis mouse models with decrease in the production of proinflammatory cytokines, autoantibodies and glomerular complement deposition, which are all characteristic features of PI3K delta (PI3Kδ) inhibition, the primary PI3K isoform expressed in lymphocytes. Importantly, PI3Kα inhibition does not impact lymphocyte function under normal conditions. These findings were then confirmed in human lymphocytes isolated from patients with active lupus nephritis. In conclusion, we demonstrate the major role played by PI3Kα in proliferative glomerulonephritis and show that in this condition, alpelisib acts on both podocytes and the immune system.

2.
Anesthesiology ; 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38787807

RESUMO

BACKGROUND: Hemorrhagic shock (HS) and rhabdomyolysis (RM) are two important risk factors of acute kidney injury (AKI) after severe trauma, however the effects of the combination of RM and HS on kidney function are unknown. The purpose of this study was to determine the impact of RM and HS on renal function, oxygenation, perfusion and morphology, in a pig model. METHODS: Forty-seven female pigs were divided into 5 groups: sham, RM, HS, HS and moderate RM (RM4/HS), HS and severe RM (RM8/HS). RM was induced by intramuscular injection of Glycerol 50% with a moderate dose (4 ml/kg for RM4/HS group) or a high dose (8 ml/kg for RM and RM8/HS groups). Among animals with HS, after 90 min of hemorrhage, animals were resuscitated with fluid followed by transfusion of the withdrawn blood. Animals were followed for 48 hours. Macro and microcirculatory parameters measurements were performed. RESULTS: RM alone induced a decrease in creatinine clearance at 48 hours (19 (0-41) vs 102 (56-116) ml/min for RM and SHAM respectively; p = 0.0006) without alteration in renal perfusion and oxygenation. HS alone impaired temporarily renal microcirculation, function and oxygenation that were restored with fluid resuscitation. RM4/HS and RM8/HS groups induced greater impairment of renal microcirculation and function than HS alone at the end of blood spoliation that were not improved by fluid resuscitation. Mortality was increased in RM8/HS and RM4/HS groups in the first 48 hours (73% vs 56% vs 9% for RM8/HS, RM4/HS and HS groups respectively). CONCLUSIONS: The combination of HS and RM induced an early deleterious effect on renal microcirculation, function and oxygenation with decreased response to resuscitation and transfusion compared with HS or RM alone.

3.
J Physiol ; 602(8): 1815-1833, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38381008

RESUMO

Renin is the key enzyme of the systemic renin-angiotensin-aldosterone system, which plays an essential role in regulating blood pressure and maintaining electrolyte and extracellular volume homeostasis. Renin is mainly produced and secreted by specialized juxtaglomerular (JG) cells in the kidney. In the present study, we report for the first time that the conserved transmembrane receptor neuropilin-1 (NRP1) participates in the development of JG cells and plays a key role in renin production. We used the myelin protein zero-Cre (P0-Cre) to abrogate Nrp1 constitutively in P0-Cre lineage-labelled cells of the kidney. We found that the P0-Cre precursor cells differentiate into renin-producing JG cells. We employed a lineage-tracing strategy combined with RNAscope quantification and metabolic studies to reveal a cell-autonomous role for NRP1 in JG cell function. Nrp1-deficient animals displayed abnormal levels of tissue renin expression and failed to adapt properly to a homeostatic challenge to sodium balance. These findings provide new insights into cell fate decisions and cellular plasticity operating in P0-Cre-expressing precursors and identify NRP1 as a novel key regulator of JG cell maturation. KEY POINTS: Renin is a centrepiece of the renin-angiotensin-aldosterone system and is produced by specialized juxtaglomerular cells (JG) of the kidney. Neuropilin-1 (NRP1) is a conserved membrane-bound receptor that regulates vascular and neuronal development, cancer aggressiveness and fibrosis progression. We used conditional mutagenesis and lineage tracing to show that NRP1 is expressed in JG cells where it regulates their function. Cell-specific Nrp1 knockout mice present with renin paucity in JG cells and struggle to adapt to a homeostatic challenge to sodium balance. The results support the versatility of renin-producing cells in the kidney and may open new avenues for therapeutic approaches.


Assuntos
Sistema Justaglomerular , Renina , Camundongos , Animais , Renina/metabolismo , Sistema Justaglomerular/metabolismo , Neuropilina-1/genética , Neuropilina-1/metabolismo , Rim/metabolismo , Camundongos Knockout , Sódio/metabolismo
4.
Nephron ; 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38412845

RESUMO

BACKGROUND: Bile acids (BAs) act not only as lipids and lipid-soluble vitamin detergents but also function as signaling molecules, participating in diverse physiological processes. The identification of BA receptors in organs beyond the enterohepatic system, such as the Farnesoid X Receptor (FXR), has initiated inquiries into their organ-specific functions. Among these organs, the kidney prominently expresses FXR. SUMMARY: This review provides a comprehensive overview of various BA species identified in kidneys and delves into the roles of renal apical and basolateral BA transporters. Furthermore, we explore changes in BAs and their potential implications in various renal diseases, particularly in chronic kidney diseases (CKD). Lastly, we center our discussion on FXR, a key BA receptor in the kidney and a potential therapeutic target for renal diseases, providing current insights into the protective mechanisms associated with FXR agonist treatments. KEY MESSAGES: Despite the relatively low concentrations of BAs in the kidney, their presence is noteworthy, with rodents and humans exhibiting distinct renal BA compositions. Renal BA transporters efficiently facilitate either reabsorption into systemic circulation or excretion into the urine. However, adaptive changes in BA transporters are evident during cholestasis. Various renal diseases are accompanied by alterations in BA concentrations and FXR expression. Consequently, the activation of FXR in the kidney could be a promising target for mitigating kidney damage.

5.
Autophagy ; : 1-2, 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38362917

RESUMO

Shear stress induced by urinary flow stimulates macroautophagy (hereafter referred to as autophagy) in kidney proximal tubule epithelial cells. Autophagy and selective degradation of lipid droplets by lipophagy contribute to tubule homeostasis by the production of ATP and control of epithelial cell size. Autophagy/lipophagy is controlled by a signaling cascade emanating from the primary cilium, localized at the apical side of epithelial cells. Downstream of the primary cilium, AMPK controls mitochondrial biogenesis on the one hand and autophagy/lipophagy on the other hand, which together increase fatty acid production that fuels oxidative phosphorylation to increase energy production. Recently, we reported that the co-transcriptional factors YAP1 and WWTR1/TAZ act downstream of AMPK to control autophagy. In fact, YAP1 and the transcription factor TEAD control the expression of RUBCN/rubicon. Under shear stress, YAP1 is excluded from the nucleus in a SIRT1-dependent manner to favor autophagic flux by downregulating the expression of RUBCN. When simulating in vitro a pathological urinary flow in murine proximal tubule kidney epithelial cells, we observe the nuclear retention of YAP1 and, consequently, high expression of RUBCN and inhibition of autophagic flux. Importantly, these findings were confirmed in biopsies of patients suffering from diabetic nephropathy, a major cause of chronic kidney disease.

6.
Proc Natl Acad Sci U S A ; 121(5): e2308776121, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38252831

RESUMO

We present a drug design strategy based on structural knowledge of protein-protein interfaces selected through virus-host coevolution and translated into highly potential small molecules. This approach is grounded on Vinland, the most comprehensive atlas of virus-human protein-protein interactions with annotation of interacting domains. From this inspiration, we identified small viral protein domains responsible for interaction with human proteins. These peptides form a library of new chemical entities used to screen for replication modulators of several pathogens. As a proof of concept, a peptide from a KSHV protein, identified as an inhibitor of influenza virus replication, was translated into a small molecule series with low nanomolar antiviral activity. By targeting the NEET proteins, these molecules turn out to be of therapeutic interest in a nonalcoholic steatohepatitis mouse model with kidney lesions. This study provides a biomimetic framework to design original chemistries targeting cellular proteins, with indications going far beyond infectious diseases.


Assuntos
Influenza Humana , Vírus , Animais , Camundongos , Humanos , Proteoma , Peptídeos/farmacologia , Descoberta de Drogas
7.
Nat Commun ; 14(1): 8056, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38052799

RESUMO

Shear stress generated by urinary fluid flow is an important regulator of renal function. Its dysregulation is observed in various chronic and acute kidney diseases. Previously, we demonstrated that primary cilium-dependent autophagy allows kidney epithelial cells to adapt their metabolism in response to fluid flow. Here, we show that nuclear YAP/TAZ negatively regulates autophagy flux in kidney epithelial cells subjected to fluid flow. This crosstalk is supported by a primary cilium-dependent activation of AMPK and SIRT1, independently of the Hippo pathway. We confirm the relevance of the YAP/TAZ-autophagy molecular dialog in vivo using a zebrafish model of kidney development and a unilateral ureteral obstruction mouse model. In addition, an in vitro assay simulating pathological accelerated flow observed at early stages of chronic kidney disease (CKD) activates YAP, leading to a primary cilium-dependent inhibition of autophagic flux. We confirm this YAP/autophagy relationship in renal biopsies from patients suffering from diabetic kidney disease (DKD), the leading cause of CKD. Our findings demonstrate the importance of YAP/TAZ and autophagy in the translation of fluid flow into cellular and physiological responses. Dysregulation of this pathway is associated with the early onset of CKD.


Assuntos
Insuficiência Renal Crônica , Sirtuína 1 , Animais , Camundongos , Humanos , Sirtuína 1/genética , Proteínas Quinases Ativadas por AMP , Peixe-Zebra , Autofagia/fisiologia , Insuficiência Renal Crônica/genética , Células Epiteliais/fisiologia , Rim
8.
Cell Rep ; 42(9): 113032, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37624695

RESUMO

Mitochondrial dysfunction is a critical process in renal epithelial cells upon kidney injury. While its implication in kidney disease progression is established, the mechanisms modulating it remain unclear. Here, we describe the role of Lipocalin-2 (LCN2), a protein expressed in injured tubular cells, in mitochondrial dysfunction. We show that LCN2 expression decreases mitochondrial mass and function and induces mitochondrial fragmentation. Importantly, while LCN2 expression favors DRP1 mitochondrial recruitment, DRP1 inhibition antagonizes LCN2's effect on mitochondrial shape. Remarkably, LCN2 promotes mitochondrial fragmentation independently of its secretion or transport iron activity. Mechanistically, intracellular LCN2 expression increases mTOR activity, and rapamycin inhibits LCN2's effect on mitochondrial shape. In vivo, Lcn2 gene inactivation prevents mTOR activation and mitochondrial length decrease observed upon ischemia-reperfusion-induced kidney injury (IRI) in Lcn2+/+ mice. Our data identify LCN2 as a key regulator of mitochondrial dynamics and further elucidate the mechanisms leading to mitochondrial dysfunction.


Assuntos
Rim , Traumatismo por Reperfusão , Camundongos , Animais , Lipocalina-2/genética , Lipocalina-2/metabolismo , Rim/metabolismo , Traumatismo por Reperfusão/metabolismo , Células Epiteliais/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Mitocôndrias/metabolismo
9.
EBioMedicine ; 93: 104635, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37285616

RESUMO

BACKGROUND: Urinary biomarkers may improve the prediction of chronic kidney disease (CKD) progression. Yet, data reporting the applicability of most commercial biomarker assays to the detection of their target analyte in urine together with an evaluation of their predictive performance are scarce. METHODS: 30 commercial assays (ELISA) were tested for their ability to quantify the target analyte in urine using strict (FDA-approved) validation criteria. In an exploratory analysis, LASSO (Least Absolute Shrinkage and Selection Operator) logistic regression analysis was used to identify potentially complementary biomarkers predicting fast CKD progression, determined as the 51CrEDTA clearance-based measured glomerular filtration rate (mGFR) decline (>10% per year) in a subsample of 229 CKD patients (mean age, 61 years; 66% men; baseline mGFR, 38 mL/min) from the NephroTest prospective cohort. FINDINGS: Among the 30 assays, directed against 24 candidate biomarkers, encompassing different pathophysiological mechanisms of CKD progression, 16 assays fulfilled the FDA-approved criteria. LASSO logistic regressions identified a combination of five biomarkers including CCL2, EGF, KIM1, NGAL, and TGF-α that improved the prediction of fast mGFR decline compared to the kidney failure risk equation variables alone: age, gender, mGFR, and albuminuria. Mean area under the curves (AUC) estimated from 100 re-samples was higher in the model with than without these biomarkers, 0.722 (95% confidence interval 0.652-0.795) vs. 0.682 (0.614-0.748), respectively. Fully-adjusted odds-ratios (95% confidence interval) for fast progression were 1.87 (1.22, 2.98), 1.86 (1.23, 2.89), 0.43 (0.25, 0.70), 1.10 (0.71, 1.83), 0.55 (0.33, 0.89), and 2.99 (1.89, 5.01) for albumin, CCL2, EGF, KIM1, NGAL, and TGF-α, respectively. INTERPRETATION: This study provides a rigorous validation of multiple assays for relevant urinary biomarkers of CKD progression which combination may improve the prediction of CKD progression. FUNDING: This work was supported by Institut National de la Santé et de la Recherche Médicale, Université de Paris, Assistance Publique Hôpitaux de Paris, Agence Nationale de la Recherche, MSDAVENIR, Pharma Research and Early Development Roche Laboratories (Basel, Switzerland), and Institut Roche de Recherche et Médecine Translationnelle (Paris, France).


Assuntos
Insuficiência Renal Crônica , Fator de Crescimento Transformador alfa , Masculino , Humanos , Pessoa de Meia-Idade , Feminino , Prognóstico , Lipocalina-2 , Estudos Prospectivos , Fator de Crescimento Epidérmico , Progressão da Doença , Biomarcadores/urina , Taxa de Filtração Glomerular
10.
JCI Insight ; 8(5)2023 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-36749641

RESUMO

Acute kidney injury is one of the most important complications in patients with COVID-19 and is considered a negative prognostic factor with respect to patient survival. The occurrence of direct infection of the kidney by SARS-CoV-2, and its contribution to the renal deterioration process, remain controversial issues. By studying 32 renal biopsies from patients with COVID-19, we verified that the major pathological feature of COVID-19 is acute tubular injury (ATI). Using single-molecule fluorescence in situ hybridization, we showed that SARS-CoV-2 infected living renal cells and that infection, which paralleled renal angiotensin-converting enzyme 2 expression levels, was associated with increased death. Mechanistically, a transcriptomic analysis uncovered specific molecular signatures in SARS-CoV-2-infected kidneys as compared with healthy kidneys and non-COVID-19 ATI kidneys. On the other hand, we demonstrated that SARS-CoV-2 and hantavirus, 2 RNA viruses, activated different genetic networks despite triggering the same pathological lesions. Finally, we identified X-linked inhibitor of apoptosis-associated factor 1 as a critical target of SARS-CoV-2 infection. In conclusion, this study demonstrated that SARS-CoV-2 can directly infect living renal cells and identified specific druggable molecular targets that can potentially aid in the design of novel therapeutic strategies to preserve renal function in patients with COVID-19.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/metabolismo , COVID-19/complicações , Hibridização in Situ Fluorescente , Rim/patologia , Biópsia
11.
Transplantation ; 107(5): 1089-1101, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36398319

RESUMO

BACKGROUND: Increasing evidence suggest that microRNAs are involved in the physiopathology of acute or chronic renal disease. In kidney transplantation, as key regulators of cellular homeostasis, microRNAs may be involved in the regulation of immune cell function and the allograft response. Here, we investigated the change in circulating microRNA expression profile and their involvement in the profound transcriptional changes associated with antibody-mediated rejection (AMR). METHODS: Blood samples were collected at the time of the 710 kidney allograft biopsies at 4 European transplant centers. Messenger RNA and microRNA profiling analyses were performed in a discovery-to-validation study within 3 independent cohorts encompassing N = 126, N = 135, and N = 416 patients, respectively. RESULTS: Compared with samples with no AMR, 14 microRNAs were significantly decreased in AMR samples. Among them, expression levels of microRNA-15b, microRNA-106a, and microRNA-374a gradually decreased with the severity of AMR lesions. From their in silico-predicted target genes, a high proportion proved to be significantly upregulated in the paired transcriptomic analysis. Gene ontology analyses of microRNA-15b/-106a/-374a suggested enrichment in myeloid-related pathways, which was further refined by in silico and ex vivo transcriptomic analyses, showing a specific origin from classical CD14 + monocytes. Finally, human CD14 + monocytes were subjected to transduction by antago-microRNAs to mimic AMR pathology. MicroRNA-15b/-106a/-374a impairment resulted in cellular activation with an increased expression of CD69, CRIM1, IPO7, and CAAP1, direct and common targets of the 3 microRNAs. CONCLUSIONS: Together, our data provide new insights into circulating microRNAs as markers and key players in AMR, and they suggest monocyte involvement in this process.


Assuntos
Transplante de Rim , MicroRNAs , Humanos , Transplante de Rim/efeitos adversos , Monócitos/metabolismo , MicroRNAs/metabolismo , Transplante Homólogo , Perfilação da Expressão Gênica/métodos , Anticorpos , Rejeição de Enxerto
13.
Am J Respir Crit Care Med ; 206(1): 34-43, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35394403

RESUMO

Rationale: Norepinephrine (NE) is commonly used in combination with fluid during resuscitation of hemorrhagic shock, but its impact on kidney microcirculation, oxygenation, and function is still unknown in this setting. Objectives: During hemorrhagic shock resuscitation, does a combination of fluid and NE affect kidney oxygenation tension, kidney microcirculatory perfusion, and 48-hour kidney function, as compared with fluid alone? Methods: Hemorrhagic shock was induced in 24 pigs, and 8 pigs were included as a sham group. Resuscitation of hemorrhagic shock was performed, using a closed-loop device, either by fluid alone (0.9% NaCl; fluid group) or associated with the administration of NE at two doses (moderate dose: mean rate of 0.64 µg ⋅ kg-1 ⋅ min-1; high dose: mean rate of 1.57 µg ⋅ kg-1 ⋅ min-1) to obtain a target systolic arterial pressure of 80 to 90 mm Hg. Resuscitation was followed by transfusion of the withdrawn blood. Measurements and Main Results: The amount of fluid required to reach the target systolic arterial pressure was lower in the NE groups than in the fluid group, with subsequently less hemodilution. NE restored kidney microcirculation, oxygenation, and function in a manner comparable to that achieved with fluid resuscitation alone. There were no histologic differences between animals resuscitated with fluid and those resuscitated with NE. Conclusions: In pigs with hemorrhagic shock, resuscitation with a combination of NE and fluid restored kidney microcirculation and oxygenation, as well as renal function, in a manner comparable to fluid resuscitation alone and without differences between the two NE doses. NE administration led to a fluid volume-sparing effect with subsequently less hemodilution.


Assuntos
Choque Hemorrágico , Animais , Hidratação , Rim/fisiologia , Microcirculação , Norepinefrina/uso terapêutico , Ressuscitação , Choque Hemorrágico/terapia , Suínos
14.
Kidney Int ; 102(1): 78-95, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35337891

RESUMO

Kidney mass and function are sexually determined, but the cellular events and the molecular mechanisms involved in this dimorphism are poorly characterized. By combining female and male mice with castration/replacement experiments, we showed that male mice exhibited kidney overgrowth from five weeks of age. This effect was organ specific, since liver and heart weight were comparable between males and females, regardless of age. Consistently, the androgen receptor was found to be expressed in the kidneys of males, but not in the liver. In growing mice, androgens led to kidney overgrowth by first inducing a burst of cell proliferation and then an increase of cell size. Remarkably, androgens were also required to maintain cell size in adults. In fact, orchiectomy resulted in smaller kidneys in a matter of few weeks. These changes paralleled the changes of the expression of ornithine decarboxylase and cyclin D1, two known mediators of kidney growth, whereas, unexpectedly, mTORC1 and Hippo pathways did not seem to be involved. Androgens also enhanced kidney autophagy, very likely by increasing transcription factor EB nuclear translocation. Functionally, the increase of tubular mass resulted in increased sodium/phosphate transport. These findings were relevant to humans. Remarkably, by studying living gender-paired kidney donors-recipients, we showed that tubular cell size increased three months after transplantation in men as compared to women, regardless of the donor gender. Thus, our results identify novel signaling pathways that may be involved in androgen-induced kidney growth and homeostasis and suggest that androgens determine kidney size after transplantation.


Assuntos
Androgênios , Caracteres Sexuais , Androgênios/farmacologia , Animais , Feminino , Homeostase , Humanos , Rim , Masculino , Camundongos , Tamanho do Órgão
15.
Life Sci Alliance ; 5(4)2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34996842

RESUMO

The current COVID-19 pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The positive-sense single-stranded RNA virus contains a single linear RNA segment that serves as a template for transcription and replication, leading to the synthesis of positive and negative-stranded viral RNA (vRNA) in infected cells. Tools to visualize vRNA directly in infected cells are critical to analyze the viral replication cycle, screen for therapeutic molecules, or study infections in human tissue. Here, we report the design, validation, and initial application of FISH probes to visualize positive or negative RNA of SARS-CoV-2 (CoronaFISH). We demonstrate sensitive visualization of vRNA in African green monkey and several human cell lines, in patient samples and human tissue. We further demonstrate the adaptation of CoronaFISH probes to electron microscopy. We provide all required oligonucleotide sequences, source code to design the probes, and a detailed protocol. We hope that CoronaFISH will complement existing techniques for research on SARS-CoV-2 biology and COVID-19 pathophysiology, drug screening, and diagnostics.


Assuntos
COVID-19/diagnóstico , Hibridização in Situ Fluorescente/métodos , RNA Viral/genética , SARS-CoV-2/genética , Replicação Viral/genética , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/farmacologia , Alanina/análogos & derivados , Alanina/farmacologia , Animais , Antivirais/farmacologia , COVID-19/virologia , Células CACO-2 , Linhagem Celular Tumoral , Chlorocebus aethiops , Humanos , Hibridização In Situ/métodos , Microscopia Eletrônica/métodos , RNA Viral/ultraestrutura , Reprodutibilidade dos Testes , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/fisiologia , Sensibilidade e Especificidade , Células Vero , Liberação de Vírus/efeitos dos fármacos , Liberação de Vírus/genética , Liberação de Vírus/fisiologia , Replicação Viral/efeitos dos fármacos , Replicação Viral/fisiologia , Tratamento Farmacológico da COVID-19
17.
EMBO Mol Med ; 13(11): e14146, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34725920

RESUMO

The mechanisms underlying the development of glomerular lesions during aging are largely unknown. It has been suggested that senescence might play a role, but the pathophysiological link between senescence and lesion development remains unexplained. Here, we uncovered an unexpected role for glomerular endothelial cells during aging. In fact, we discovered a detrimental cross-talk between senescent endothelial cells and podocytes, through PAI-1. In vivo, selective inactivation of PAI-1 in endothelial cells protected glomeruli from lesion development and podocyte loss in aged mice. In vitro, blocking PAI-1 in supernatants from senescent endothelial cells prevented podocyte apoptosis. Consistently, depletion of senescent cells prevented podocyte loss in old p16 INK-ATTAC transgenic mice. Importantly, these experimental findings are relevant to humans. We showed that glomerular PAI-1 expression was predictive of poor outcomes in transplanted kidneys from elderly donors. In addition, we observed that in elderly patients, urinary PAI-1 was associated with age-related chronic kidney disease. Altogether, these results uncover a novel mechanism of kidney disease and identify PAI-1 as a promising biomarker of kidney dysfunction in allografts from elderly donors.


Assuntos
Nefropatias , Podócitos , Idoso , Animais , Senescência Celular , Células Endoteliais , Humanos , Glomérulos Renais , Camundongos , Inibidor 1 de Ativador de Plasminogênio
18.
J Am Soc Nephrol ; 32(8): 1974-1986, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34078664

RESUMO

BACKGROUND: CKD is associated with the loss of functional nephr ons, leading to increased mechanical and metabolic stress in the remaining cells, particularly for cells constituting the filtration barrier, such as podocytes. The failure of podocytes to mount an adequate stress response can lead to further nephron loss and disease progression. However, the mechanisms that regulate this degenerative process in the kidney are unknown. METHODS: We combined in vitro, in vivo, and organ-on-chip approaches to identify the RE1-silencing transcription factor (REST), a repressor of neuronal genes during embryonic development, as a central regulator of podocyte adaptation to injury and aging. RESULTS: Mice with a specific deletion of REST in podocytes exhibit albuminuria, podocyte apoptosis, and glomerulosclerosis during aging, and exhibit increased vulnerability to renal injury. This phenotype is mediated, in part, by the effects of REST on the podocyte cytoskeleton that promote resistance to mechanical stressors and augment podocyte survival. Finally, REST expression is upregulated in human podocytes during aging, consistent with a conserved mechanism of stress resistance. CONCLUSIONS: These results suggest REST protects the kidney from injury and degeneration during aging, with potentially important therapeutic implications.


Assuntos
Adaptação Fisiológica/genética , Envelhecimento/fisiologia , Podócitos/patologia , Podócitos/fisiologia , Proteínas Repressoras/genética , Estresse Fisiológico/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Albuminúria/genética , Animais , Apoptose/genética , Linhagem Celular , Sobrevivência Celular , Citoesqueleto/fisiologia , Regulação da Expressão Gênica/genética , Homeostase/genética , Humanos , Camundongos , Fenótipo , Proteínas Repressoras/metabolismo , Esclerose , Adulto Jovem
19.
Kidney Int ; 99(4): 805-808, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33745545

RESUMO

Gorski et al. report a meta-GWAS of rapid kidney function decline in 42 longitudinal studies from the CKDGen Consortium and UK Biobank, amounting to more than 270'000 individuals with two eGFRcrea measurements. They identified genome-wide significant variants associated with two indexes of rapid kidney function decline, involving genes with a high potential for causality. These data increase our understanding of kidney function and risk of disease.


Assuntos
Estudo de Associação Genômica Ampla , Rim , Taxa de Filtração Glomerular , Humanos , Estudos Longitudinais
20.
J Am Soc Nephrol ; 32(12): 3231-3251, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-35167486

RESUMO

BACKGROUND: After kidney transplantation, donor-specific antibodies against human leukocyte antigen donor-specific antibodies (HLA-DSAs) drive antibody-mediated rejection (ABMR) and are associated with poor transplant outcomes. However, ABMR histology (ABMRh) is increasingly reported in kidney transplant recipients (KTRs) without HLA-DSAs, highlighting the emerging role of non-HLA antibodies (Abs). METHODS: W e designed a non-HLA Ab detection immunoassay (NHADIA) using HLA class I and II-deficient glomerular endothelial cells (CiGEnCΔHLA) that had been previously generated through CRISPR/Cas9-induced B2M and CIITA gene disruption. Flow cytometry assessed the reactivity to non-HLA antigens of pretransplantation serum samples from 389 consecutive KTRs. The intensity of the signal observed with the NHADIA was associated with post-transplant graft histology assessed in 951 adequate biopsy specimens. RESULTS: W e sequentially applied CRISPR/Cas9 to delete the B2M and CIITA genes to obtain a CiGEnCΔHLA clone. CiGEnCΔHLA cells remained indistinguishable from the parental cell line, CiGEnC, in terms of morphology and phenotype. Previous transplantation was the main determinant of the pretransplantation NHADIA result (P<0.001). Stratification of 3-month allograft biopsy specimens (n=298) according to pretransplantation NHADIA tertiles demonstrated that higher levels of non-HLA Abs positively correlated with increased glomerulitis (P=0.002), microvascular inflammation (P=0.003), and ABMRh (P=0.03). A pretransplantation NHADIA threshold of 1.87 strongly discriminated the KTRs with the highest risk of ABMRh (P=0.005, log-rank test). A multivariate Cox model confirmed that NHADIA status and HLA-DSAs were independent, yet synergistic, predictors of ABMRh. CONCLUSION: The NHADIA identifies non-HLA Abs and strongly predicts graft endothelial injury independent of HLA-DSAs.


Assuntos
Sistemas CRISPR-Cas/genética , Rejeição de Enxerto/etiologia , Antígenos HLA/imunologia , Isoanticorpos/imunologia , Glomérulos Renais/imunologia , Transplante de Rim/efeitos adversos , Doadores de Tecidos , Adulto , Idoso , Células Cultivadas , Células Endoteliais/imunologia , Feminino , Deleção de Genes , Antígenos HLA/genética , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares/genética , Reoperação , Estudos Retrospectivos , Transativadores/genética , Microglobulina beta-2/genética
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