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Background: Minimal change disease (MCD) is a common cause of adult nephrotic syndrome. Most adults with MCD achieve complete remission (CR) after initial steroid therapy. However, approximately 30% of adults who respond to steroids experience frequent relapses, becoming steroid-dependent and potentially developing refractory MCD. Treating refractory MCD in adults poses a significant challenge. Main body: A 37-year-old woman presented to the nephrology department with a 6-year history of MCD. The diagnosis of MCD was confirmed via renal biopsy. She initially achieved CR with steroid treatment but experienced relapse during steroid tapering. Subsequent CR was achieved with a regimen of steroids and tacrolimus although multiple relapses occurred. Rituximab led to another CR, but its maintenance lasted only 6 months. The response to subsequent rituximab treatments was unsatisfactory. Ultimately, obinutuzumab was selected, resulting in the induction and maintenance of CR for 12 months. Conclusions: This case demonstrates the successful treatment of frequently relapsed, steroid-dependent, and rituximab-resistant MCD with obinutuzumab. Obinutuzumab is a promising therapeutic option for rituximab-resistant MCD.
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Anticuerpos Monoclonales Humanizados , Nefrosis Lipoidea , Rituximab , Humanos , Adulto , Femenino , Nefrosis Lipoidea/tratamiento farmacológico , Rituximab/uso terapéutico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Resistencia a Medicamentos , Resultado del Tratamiento , Inducción de Remisión , RecurrenciaRESUMEN
Human umbilical cord mesenchymal stem cells-derived small extracellular vesicles (MSC-sEV) provide a pragmatic solution as a cell-free therapy for patients with diabetic kidney disease (DKD). However, the underlying protective mechanisms of MSC-sEV remain largely unknown in DKD. Invivo and in vitro analyses demonstrated that MSC-sEV attenuated renal fibrosis and inflammation of DKD. The underlying mechanism of the MSC-sEV-induced therapeutic effect was explored by high-throughput sequencing, which identified the unique enrichment of a set of miRNAs in MSC-sEV compared with human skin fibroblasts-sEV (HSF-sEV). Vitro experiments demonstrated that the protective potential was primarily attributed to miR-23a-3p, one of the most abundant miRNAs in MSC-sEV. Further, overexpression or knockdown analyses revealed that miR-23a-3p, and its target Krüppel-like factor 3 (KLF3) suppressed the STAT3 signaling pathway in high glucose (HG) induced HK-2 cells were essential for the renal-protective property of MSC-sEV. Moreover, we found that miR-23a-3p was packaged into MSC-sEV by RNA Binding Motif Protein X-Linked (RBMX) and transmitted to HG-induced HK-2 cells. Finally, inhibiting miR-23a-3p could mitigate the protective effects of MSC-sEV in db/db mice. These findings suggest that a systemic administration of sEV derived from MSC, have the capacity to incorporate into kidney where they can exert renal-protective potential against HG-induced injury through delivery of miR-23a-3p.
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Nefropatías Diabéticas , Vesículas Extracelulares , Fibrosis , Factores de Transcripción de Tipo Kruppel , Células Madre Mesenquimatosas , MicroARNs , Factor de Transcripción STAT3 , MicroARNs/genética , MicroARNs/metabolismo , Nefropatías Diabéticas/terapia , Nefropatías Diabéticas/genética , Nefropatías Diabéticas/metabolismo , Células Madre Mesenquimatosas/metabolismo , Animales , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/trasplante , Humanos , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción STAT3/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción de Tipo Kruppel/genética , Ratones , Masculino , Transducción de Señal , Línea Celular , Ratones Endogámicos C57BL , Riñón/patología , Riñón/metabolismo , InflamaciónRESUMEN
Background: Immunoglobulin A nephropathy (IgAN) and idiopathic membranous nephropathy (IMN) are the most common glomerular diseases. Immunofluorescence (IF) tests of renal tissues are crucial for the diagnosis. We developed a multiple convolutional neural network (CNN)-facilitated diagnostic program to assist the IF diagnosis of IgAN and IMN. Methods: The diagnostic program consisted of four parts: a CNN trained as a glomeruli detection module, an IF intensity comparator, dual-CNN (D-CNN) trained as a deposition appearance and location classifier and a post-processing module. A total of 1573 glomerular IF images from 1009 patients with glomerular diseases were used for the training and validation of the diagnostic program. A total of 1610 images of 426 patients from different hospitals were used as test datasets. The performance of the diagnostic program was compared with nephropathologists. Results: In >90% of the tested images, the glomerulus location module achieved an intersection over union >0.8. The accuracy of the D-CNN in recognizing irregular granular mesangial deposition and fine granular deposition along the glomerular basement membrane was 96.1% and 93.3%, respectively. As for the diagnostic program, the accuracy, sensitivity and specificity of diagnosing suspected IgAN were 97.6%, 94.4% and 96.0%, respectively. The accuracy, sensitivity and specificity of diagnosing suspected IMN were 91.7%, 88.9% and 95.8%, respectively. The corresponding areas under the curve (AUCs) were 0.983 and 0.935. When tested with images from the outside hospital, the diagnostic program showed stable performance. The AUCs for diagnosing suspected IgAN and IMN were 0.972 and 0.948, respectively. Compared with inexperienced nephropathologists, the program showed better performance. Conclusion: The proposed diagnostic program could assist the IF diagnosis of IgAN and IMN.
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(A) Immunofluorescence staining showed moderate immunoglobulin A depositions in the mesangial areas (++) of glomeruli (Bars = 100 µm). (B) Segmentally mild mesangial proliferation and mesangial matrix expansion (arrowhead) with mild thickening of glomerular capillary walls (PAS, ×400).
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Phosphatase and tensin homolog (PTEN) loss tightly correlates with prostate cancer (PCa) progression and metastasis. Inactivation of PTEN leads to abnormal activation of PI3K/AKT pathway. However, results from clinical trials with AKT inhibitors in PCa have been largely disappointing. Identification of novel regulators of PTEN in PTEN-dysfunctional PCa is urgently needed. Here we demonstrated that the expression level of PTEN is inversely correlated with the signature score of unfolded protein response (UPR) in PCa. Importantly, PTEN suppresses the activity of ATF6α, via interacting to de-phosphorylate ATF6α and consequently inhibiting its nuclear translocation. Conversely, ATF6α promotes the ubiquitination and degradation of PTEN by inducing CHIP expression. Thus, ATF6α and PTEN forms a negative feedback loop during PCa progression. Combination of ATF6α inhibitor with AKT inhibitor suppresses tumor cell proliferation and xenograft growth. Importantly, this study highlighted ATF6α as a therapeutic vulnerability in PTEN dysfunctional PCa.
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Fosfatidilinositol 3-Quinasas , Neoplasias de la Próstata , Masculino , Humanos , Retroalimentación , Proteínas Proto-Oncogénicas c-akt , Neoplasias de la Próstata/genética , Próstata , Inhibidores de la Angiogénesis , Inhibidores de Proteínas Quinasas , Fosfohidrolasa PTEN/genéticaRESUMEN
Vascular calcification (VC) is a common complication of chronic kidney disease (CKD) and contributes to an increased risk of cardiovascular morbidity and mortality. However, effective therapies are still unavailable at present. It has been well established that VC associated with CKD is not a passive process of calcium phosphate deposition, but an actively regulated and cell-mediated process that shares many similarities with bone formation. Additionally, numerous studies have suggested that CKD patients have specific risk factors and contributors to the development of VC, such as hyperphosphatemia, uremic toxins, oxidative stress and inflammation. Although research efforts in the past decade have greatly improved our knowledge of the multiple factors and mechanisms involved in CKD-related VC, many questions remain unanswered. Moreover, studies from the past decade have demonstrated that epigenetic modifications abnormalities, such as DNA methylation, histone modifications and noncoding RNAs, play an important role in the regulation of VC. This review seeks to provide an overview of the pathophysiological and molecular mechanisms of VC associated with CKD, mainly focusing on the involvement of epigenetic modifications in the initiation and progression of uremic VC, with the aim to develop promising therapies for CKD-related cardiovascular events in the future.
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Hiperfosfatemia , Insuficiencia Renal Crónica , Calcificación Vascular , Humanos , Riñón , Calcificación Vascular/etiología , Fosfatos , Hiperfosfatemia/complicaciones , Hiperfosfatemia/genética , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/genéticaRESUMEN
Renal tubular epithelial cells (TECs) play a key role in kidney fibrosis by mediating cycle arrest at G2/M. However, the key HDAC isoforms and the underlying mechanism that are involved in G2/M arrest of TECs remain unclear. Here, we find that Hdac9 expression is significantly induced in the mouse fibrotic kidneys, especially in proximal tubules, induced by aristolochic acid nephropathy (AAN) or unilateral ureter obstruction (UUO). Tubule-specific deletion of HDAC9 or pharmacological inhibition by TMP195 attenuates epithelial cell cycle arrest in G2/M, then reduces production of profibrotic cytokine and alleviates tubulointerstitial fibrosis in male mice. In vitro, knockdown or inhibition of HDAC9 alleviates the loss of epithelial phenotype in TECs and attenuates fibroblasts activation through inhibiting epithelial cell cycle arrest in G2/M. Mechanistically, HDAC9 deacetylates STAT1 and promotes its reactivation, followed by inducing G2/M arrest of TECs, finally leading to tubulointerstitial fibrosis. Collectively, our studies indicate that HDAC9 may be an attractive therapeutic target for kidney fibrosis.
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Enfermedades Renales , Obstrucción Ureteral , Animales , Masculino , Ratones , Apoptosis , Puntos de Control del Ciclo Celular/genética , Línea Celular Tumoral , Células Epiteliales/metabolismo , Fibrosis , Puntos de Control de la Fase G2 del Ciclo Celular/genética , Riñón/metabolismo , Enfermedades Renales/patología , Túbulos Renales Proximales/metabolismo , Obstrucción Ureteral/metabolismoRESUMEN
Renal fibrosis is the common histopathological feature of chronic kidney diseases (CKD), and there is increasing evidence that epigenetic regulation is involved in the occurrence and progression of renal fibrosis. N-myc downstream-regulated gene 2 (NDRG2) is significantly down-regulated in renal fibrosis, the mechanism of which remains unclear. Previous studies have confirmed that the inhibition of NDRG2 expression in tumor cells is related to hyper-methylation, mainly regulated by DNA methyltransferases (DNMTS). Herein, we explored the expression of NDRG2 and its epigenetic regulatory mechanism in renal fibrosis. The results showed that the expression of NDRG2 was significantly inhibited in vivo and in vitro, while the overexpression of NDRG2 effectively alleviated renal fibrosis. Meanwhile, we found that the expression of DNMT1/3A/3B was significantly increased in hypoxia-induced HK2 cells and Unilateral Ureteral Obstruction (UUO) mice accompanied by hyper-methylation of the NDGR2 promoter. Methyltransferase inhibitor (5-AZA-dC) corrected the abnormal expression of DNMT1/3A/3B, reduced the methylation level of NDRG2 promoter and restored the expression of NDRG2. The upstream events that mediate changes in NDRG2 methylation were further explored. Reactive oxygen species (ROS) are important epigenetic regulators and have been shown to play a key role in renal injury due to various causes. Accordingly, we further explored whether ROS could induce DNA-epigenetic changes of the expression of NDRG2 and then participated in the development of renal fibrosis. Our results showed that mitochondria-targeted antioxidants (Mito-TEMPO) could reverse the epigenetic inhibition of NDRG2 in a DNMT-sensitive manner, showing strong ability of DNA demethylation, exhibiting epigenetic regulation and anti-fibrosis effects similar to 5-AZA-dC. More importantly, the anti-fibrotic effects of 5-AZA-dC and Mito-TEMPO were eliminated in HK2 cells with NDRG2 knockdown. These findings highlight that targeting ROS-mediated hyper-methylation of NDRG2 promoter is a potentially effective therapeutic strategy for renal fibrosis, which will provide new insights into the treatment of CKD.
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ADN de Forma A , Insuficiencia Renal Crónica , Animales , Ratones , Epigénesis Genética , Especies Reactivas de Oxígeno , Metiltransferasas/genética , Metilación de ADN , Fibrosis , Insuficiencia Renal Crónica/patología , Azacitidina/uso terapéuticoRESUMEN
Dysfunction of podocytes has been regarded as an important early pathologic characteristic of diabetic kidney disease (DKD), but the regulatory role of long noncoding RNAs (lncRNAs) in this process remains largely unknown. Here, we performed RNA sequencing in kidney tissues isolated from DKD patients and nondiabetic renal cancer patients undergoing surgical resection and discovered that the novel lncRNA ENST00000436340 was upregulated in DKD patients and high glucose-induced podocytes, and we showed a significant correlation between ENST00000436340 and kidney injury. Gain- and loss-of-function experiments showed that silencing ENST00000436340 alleviated high glucose-induced podocyte injury and cytoskeleton rearrangement. Mechanistically, we showed that fat mass and obesity- associate gene (FTO)-mediated m6A induced the upregulation of ENST00000436340. ENST00000436340 interacted with polypyrimidine tract binding protein 1 (PTBP1) and augmented PTBP1 binding to RAB3B mRNA, promoted RAB3B mRNA degradation, and thereby caused cytoskeleton rearrangement and inhibition of GLUT4 translocation to the plasma membrane, leading to podocyte injury and DKD progression. Together, our results suggested that upregulation of ENST00000436340 could promote podocyte injury through PTBP1-dependent RAB3B regulation, thus suggesting a novel form of lncRNA-mediated epigenetic regulation of podocytes that contributes to the pathogenesis of DKD.
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Diabetes Mellitus , Nefropatías Diabéticas , Podocitos , ARN Largo no Codificante , Humanos , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato/metabolismo , Diabetes Mellitus/patología , Nefropatías Diabéticas/patología , Epigénesis Genética , Glucosa/metabolismo , Ribonucleoproteínas Nucleares Heterogéneas/genética , Ribonucleoproteínas Nucleares Heterogéneas/metabolismo , Podocitos/metabolismo , Proteína de Unión al Tracto de Polipirimidina/genética , Proteína de Unión al Tracto de Polipirimidina/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismoRESUMEN
Karyomegalic interstitial nephritis (KIN) is a rare kidney disease marked by large tubular nuclei, interstitial inflammation, tubular atrophy, and interstitial fibrosis. The current study presented the case of a 39-year-old man with deteriorating kidney function and a serum creatinine level of 2.08 mg/dL. The renal biopsy revealed that the main pathological features of renal tubular epithelial cells were obvious enlargement, irregular shape, and hyperchromatic nuclei. The genetic analysis of the patient revealed two heterozygous variants in the FAN1 gene, c.2485c>T, and c.2928dupT, located in exons 10 and 13, respectively. A diagnosis of KIN was rendered. The two variations of the proband are identified in separate alleles from the father and mother, respectively, according to his family's sequencing. This phenotype is consistent with an autosomal recessive pattern of inheritance. The patient was treated with the Chinese patent medicine Niaoduqing Particles. After 38 months of follow-up, renal function was barely changed with a serum creatinine of 1.73 mg/dL.
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Nefritis Intersticial , Humanos , Creatinina , Nefritis Intersticial/genética , Nefritis Intersticial/patología , Riñón/patología , FibrosisRESUMEN
BACKGROUND: C4d may be used as a marker to evaluate the condition and prognosis of adults with IgA nephropathy, but there have been few studies of children with IgA nephropathy. METHODS: C4d immunohistochemical staining was performed on samples from children with IgA nephropathy with C1q-negative immunofluorescence. The clinical and pathological treatment and prognostic characteristics of children in the C4d-positive and -negative groups were compared. RESULTS: A total of sixty-five children with IgA nephropathy were included in the study and were followed up for an average of 37 months. C4d was mainly deposited along the capillary loops. The urinary protein-to-creatinine ratio (UPCR) in the C4d-positive group was significantly higher than that in the C4d-negative group (3.97 vs. 0.81, P < 0.001), and the average integrated optical density value of each child was positively correlated with the UPCR (r = 0.441, P < 0.001). There was a significant difference in the proportions of children with mesangial hypercellularity (M1) (68.97% vs. 44.44%, P = 0.048) and segmental glomerulosclerosis (S1) (65.52% vs. 33.33%, P = 0.010) between the C4d-positive group and the C4d-negative group. The proportion of children who received immunosuppressants in the C4d-positive group was higher than that in the C4d-negative group (86.21% vs. 36.11%, P < 0.001). There was no significant difference in the proportion of children developing kidney failure between the two groups. CONCLUSION: C4d was found to be associated with proteinuria, segmental lesions, and immunosuppressant treatment. Activation of the lectin pathway may reflect the severity of clinical and pathological manifestations of IgA nephropathy in children. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Glomerulonefritis por IGA , Adulto , Humanos , Niño , Glomerulonefritis por IGA/complicaciones , Glomerulonefritis por IGA/tratamiento farmacológico , Complemento C4b/análisis , Estudios Retrospectivos , Proteinuria/complicaciones , Gravedad del PacienteRESUMEN
The process of placental invasion is essential for a successful pregnancy. Leptin is involved in trophoblast invasiveness, and its dysregulation is connected with a series of diseases, including preeclampsia. However, the knowledge of the precise mechanisms in leptin-induced trophoblast invasiveness is still limited. According to the present research, transwell assay suggested that leptin is a dose- and time-dependent regulator in inducing HTR-8/SVneo cell invasion. Western blot analysis and immunofluorescence staining revealed that leptin-induced MMP9 expression is essential in the invasion process of HTR-8/SVneo cells. Mechanistically, we demonstrated that leptin activated ß-catenin via the crosstalk between the MTA1/WNT and PI3K/AKT pathways. Besides, we showed that downregulating the key molecules in the signaling pathways by siRNA can inhibit leptin-induced MMP9 expression and further suppress invasion of HTR-8/SVneo cells. In conclusion, our study revealed a new regulatory mechanism of leptin-induced HTR-8/SVneo cell invasiveness and will provide novel insights into the causes and potential therapeutic targets for diseases related to dysregulation of trophoblast invasion in the future.
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Leptina , Placenta , Femenino , Humanos , Embarazo , Leptina/genética , Metaloproteinasa 9 de la Matriz , Fosfatidilinositol 3-Quinasas , Placenta/fisiología , Proteínas Proto-Oncogénicas c-akt , Proteínas Represoras , Transactivadores , Trofoblastos/fisiologíaRESUMEN
Targeted therapy is an effective treatment for non-small cell lung cancer. Before treatment, pathologists need to confirm tumor morphology and type, which is time-consuming and highly repetitive. In this study, we propose a multi-task deep learning model based on a convolutional neural network for joint cancer lesion region segmentation and histological subtype classification, using magnified pathological tissue images. Firstly, we constructed a shared feature extraction channel to extract abstract information of visual space for joint segmentation and classification learning. Then, the weighted losses of segmentation and classification tasks were tuned to balance the computing bias of the multi-task model. We evaluated our model on a private in-house dataset of pathological tissue images collected from Qilu Hospital of Shandong University. The proposed approach achieved Dice similarity coefficients of 93.5% and 89.0% for segmenting squamous cell carcinoma (SCC) and adenocarcinoma (AD) specimens, respectively. In addition, the proposed method achieved an accuracy of 97.8% in classifying SCC vs. normal tissue and an accuracy of 100% in classifying AD vs. normal tissue. The experimental results demonstrated that our method outperforms other state-of-the-art methods and shows promising performance for both lesion region segmentation and subtype classification.
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Renal tubulointerstitial fibrosis is the hallmark of chronic kidney disease (CKD) and the best predictor of renal survival. However, current treatments for CKD remain extremely limited. Therefore, novel therapeutic targets are urgently needed to either stop or reverse CKD progression. The present study was designed to explore the potential role of GPR87, a member of the G protein-coupled receptors (GPCRs) family, in the pathogenesis of tubulointerstitial fibrosis. It was found that GPR87 was significantly induced in the kidney, especially in tubular areas, from different mouse models of renal fibrosis, including unilateral ureteral obstruction (UUO) nephropathy, aristolochic acid nephropathy, and diabetic nephropathy, respectively. Tubule-specific GPR87 deletion dramatically ameliorated tubulointerstitial fibrosis in UUO mice. Mechanistically, GPR87 accelerated glycolysis and mitochondrial injury by YAP-hexokinase-2 signaling, thereby promoting renal fibrosis. Importantly, the upregulation of GPR87 was also found in the kidney from patients with various CKD, indicating that the induction of GPR87 may be a common feature of human kidney diseases. Collectively, our studies for the first time demonstrate that GPR87 plays a pivotal role in renal fibrosis at least in part by accelerating glycolysis and mitochondrial injury, suggesting that targeting GPR87 may represent a novel therapeutic strategy for patients with CKD.
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Nefropatías Diabéticas , Enfermedades Renales , Receptores del Ácido Lisofosfatídico/metabolismo , Insuficiencia Renal Crónica , Obstrucción Ureteral , Animales , Nefropatías Diabéticas/metabolismo , Fibrosis , Glucólisis , Humanos , Riñón/metabolismo , Enfermedades Renales/genética , Enfermedades Renales/metabolismo , Ratones , Ratones Endogámicos C57BL , Insuficiencia Renal Crónica/metabolismo , Obstrucción Ureteral/genéticaRESUMEN
Inadequate trophoblastic invasion is considered as one of hallmarks of preeclampsia (PE), which is characterized by newly onset of hypertension (>140/90 mmHg) and proteinuria (>300 mg in a 24-h urine) after 20 weeks of gestation. Accumulating evidence has indicated that long noncoding RNAs are aberrantly expressed in PE, whereas detailed mechanisms are unknown. In the present study, we showed that lncRNA Taurine upregulated 1 (TUG1) were downregulated in preeclamptic placenta and in HTR8/SVneo cells under hypoxic conditions, together with reduced enhancer of zeste homolog2 (EZH2) and embryonic ectoderm development (EED) expression, major components of polycomb repressive complex 2 (PRC2), as well as activation of Nodal/ALK7 signalling pathway. Mechanistically, we found that TUG1 bound to PRC2 (EZH2/EED) in HTR8/SVneo cells and weakened TUG1/PRC2 interplay was correlated with upregulation of Nodal expression via decreasing H3K27me3 mark at the promoter region of Nodal gene under hypoxic conditions. And activation of Nodal signalling prohibited trophoblast invasion via reducing MMP2 levels. Overexpression of TUG1 or EZH2 significantly attenuated hypoxia-induced reduction of trophoblastic invasiveness via negative modulating Nodal/ALK7 signalling and rescuing expression of its downstream target MMP2. These investigations might provide some evidence for novel mechanisms responsible for inadequate trophoblastic invasion and might shed some light on identifying future therapeutic targets for PE.
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Preeclampsia , ARN Largo no Codificante , Receptores de Activinas Tipo I/metabolismo , Movimiento Celular/genética , Proliferación Celular/genética , Femenino , Humanos , Hipoxia/genética , Hipoxia/metabolismo , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 2 de la Matriz/metabolismo , Proteína Nodal/metabolismo , Complejo Represivo Polycomb 2/metabolismo , Preeclampsia/genética , Preeclampsia/metabolismo , Embarazo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Taurina/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Trofoblastos/metabolismoRESUMEN
The well-documented tumor suppressor p53 is also a major stress response factor for its diverse regulation on cellular energetics. However, the effect of p53 on mitochondrial biogenesis, which plays a predominant role in response to the elevated energy demands, appears to be pleiotropic in various conditions and has not reached agreement. Mitochondrial ribosomal protein L12 (MRPL12), reported as a bi-functional protein for its roles in both mitochondrial ribosomes and transcriptional complexes, is a core regulatory component in mitochondrial biogenesis. Here we proved that MRPL12 is transcriptionally regulated by p53. Furthermore, the p53/MRPL12 regulation of mitochondria is part of the signaling pathway that maintains the basal mitochondrial content and positively coordinates the mitochondrial biogenesis and oxidative phosphorylation (OXPHOS) in response to metabolic perturbation. Since p53 serves as the'Guardian of the Genome', our findings may revealed a new mechanism underlying the conditions when more ATP is warranted to maintain the genome integrity and cell survival. Therefore the pharmacological intervention or metabolic modulation (e.g., through fasting or exercise) of the p53/MRPL12 pathway promises to be a therapeutic approach that can safeguard health.
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Biogénesis de Organelos , Proteína p53 Supresora de Tumor , Mitocondrias/genética , Mitocondrias/metabolismo , Proteínas Ribosómicas/genética , Proteínas Ribosómicas/metabolismo , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Podocytes are unique, highly specialized, terminally differentiated cells, which are restricted in a post-mitotic state with limited ability to repair or regenerate. Re-entering the mitotic phase causes podocyte mitotic catastrophe, thereby leading to podocyte death and glomerular injury. Myeloid-derived growth factor (MYDGF) is a novel secreted protein and plays an important role in the regulation of cardiovascular function. However, whether MYDGF is expressed in kidney parenchymal cells and whether it has biological functions in the kidney remain unknown. Here, we found that MYDGF was expressed in kidney parenchymal cells and was significantly reduced in podocytes from mice with models of focal segmental glomerulosclerosis and diabetic kidney disease. Podocyte-specific deletion of Mydgf in mice exacerbated podocyte injury and proteinuria in both disease models. Functionally, MYDGF protected podocytes against mitotic catastrophe by reducing accumulation of podocytes in the S phase, a portion of the cell cycle in which DNA is replicated. Mechanistically, MYDGF regulates the expression of the transcription factor RUNX2 which mediates some MYDGF effects. Importantly, a significant reduction of MYDGF was found in glomeruli from patients with glomerular disease due to focal segmental glomerulosclerosis and diabetic kidney disease and the level of MYDGF was correlated with glomerular filtration rate, serum creatinine and podocyte loss. Thus, our studies indicate that MYDGF may be an attractive therapeutic target for glomerular disease.
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Nefropatías Diabéticas , Glomeruloesclerosis Focal y Segmentaria , Interleucinas , Podocitos , Animales , Nefropatías Diabéticas/complicaciones , Nefropatías Diabéticas/genética , Glomeruloesclerosis Focal y Segmentaria/metabolismo , Interleucinas/genética , Glomérulos Renales/patología , Ratones , Mitosis , Podocitos/patologíaRESUMEN
Although tissue-resident-memory T (TRM) cells, a recently identified non-circulating memory T cell population, play a crucial role in mediating local immune responses and protect against pathogens upon local reinfection, the composition, effector function, and specificity of TRM cells in the kidney and their relevance for chronic kidney disease remain unknown. In this study, we found that renal tissue displayed high abundance of tissue-resident lymphocytes, and the proportion of CD8+ TRM cells was significantly increased in the kidney from patients and mice with focal segmental glomerulosclerosis (FSGS), diabetic kidney disease (DKD), and lupus nephritis (LN). Mechanistically, IL-15 significantly promoted CD8+ TRM cell formation and activation, thereby promoting podocyte injury and glomerulosclerosis. Interestingly, Sparsentan, the dual angiotensin II (Ang II) receptor and endothelin type A receptor antagonist, can also reduce TRM cell responses by intervening IL-15 signaling, exploring its new pharmacological functions. Mechanistically, Sparsentan inhibited Ang II or endothelin-1 (ET-1)-mediated IL-15 signaling, thereby further regulating renal CD8+ TRM cell fates. Collectively, our studies provide direct evidence for the pivotal role of renal CD8+ TRM cells in podocyte injury and further strengthen that targeting TRM cells represents a novel therapeutic strategy for patients with glomerular diseases.
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Memoria Inmunológica , Podocitos , Animales , Linfocitos T CD8-positivos , Interleucina-15 , Ratones , Transducción de SeñalRESUMEN
Podocyte damage is strongly associated with the progression of diabetic nephropathy. Mitotic catastrophe plays an essential role in accelerating podocyte loss and detachment from the glomerular basement membrane. In the current study, we observed that the long non-coding RNA (lncRNA) MIAT was noticeably upregulated in the plasma and kidney tissues of patients with diabetic nephropathy, and this upregulation was accompanied by higher albumin/creatinine ratios and serum creatinine levels. By generating CRISPR-Cas9 Miat-knockout (KO) mice in vivo and employing vectors in vitro, we found that the depletion of Miat expression significantly restored slit-diaphragm integrity, attenuated foot process effacement, prevented dedifferentiation, and suppressed mitotic catastrophe in podocytes during hyperglycemia. The mechanistic investigation revealed that Miat increased Sox4 expression and subsequently regulated p53 ubiquitination and acetylation, thereby inhibiting the downstream factors CyclinB/cdc2 by enhancing p21cip1/waf1 activity, and that Miat interacted with Sox4 by sponging miR-130b-3p. Additionally, the inhibition of miR-130b-3p with an antagomir in vivo effectively enhanced glomerular podocyte injury and mitotic dysfunction, eventually exacerbating proteinuria. Based on these findings, MIAT may represent a therapeutic target for diabetic nephropathy.