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2.
Cell Death Dis ; 12(9): 847, 2021 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-34518519

RESUMO

Proximal tubular epithelial cells (TECs) demand high energy and rely on mitochondrial oxidative phosphorylation as the main energy source. However, this is disturbed in renal fibrosis. Acetylation is an important post-translational modification for mitochondrial metabolism. The mitochondrial protein NAD+-dependent deacetylase sirtuin 3 (SIRT3) regulates mitochondrial metabolic function. Therefore, we aimed to identify the changes in the acetylome in tubules from fibrotic kidneys and determine their association with mitochondria. We found that decreased SIRT3 expression was accompanied by increased acetylation in mitochondria that have separated from TECs during the early phase of renal fibrosis. Sirt3 knockout mice were susceptible to hyper-acetylated mitochondrial proteins and to severe renal fibrosis. The activation of SIRT3 by honokiol ameliorated acetylation and prevented renal fibrosis. Analysis of the acetylome in separated tubules using LC-MS/MS showed that most kidney proteins were hyper-acetylated after unilateral ureteral obstruction. The increased acetylated proteins with 26.76% were mitochondrial proteins which were mapped to a broad range of mitochondrial pathways including fatty acid ß-oxidation, the tricarboxylic acid cycle (TCA cycle), and oxidative phosphorylation. Pyruvate dehydrogenase E1α (PDHE1α), which is the primary link between glycolysis and the TCA cycle, was hyper-acetylated at lysine 385 in TECs after TGF-ß1 stimulation and was regulated by SIRT3. Our findings showed that mitochondrial proteins involved in regulating energy metabolism were acetylated and targeted by SIRT3 in TECs. The deacetylation of PDHE1α by SIRT3 at lysine 385 plays a key role in metabolic reprogramming associated with renal fibrosis.

3.
Cell Death Differ ; 28(12): 3316-3328, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34175897

RESUMO

Endometrial cancer (EC) is the most common gynecological malignancy worldwide. However, the molecular mechanisms underlying EC progression are still largely unknown, and chemotherapeutic options for EC patients are currently very limited. In this study, we found that histone methyltransferase EZH2 and DNA methyltransferase DNMT3B were upregulated in EC samples from patients, and promoted EC cell proliferation as evidenced by assays of cell viability, cell cycle, colony formation. Mechanistically, we found that EZH2 promoted EC cell proliferation by epigenetically repressing TCF3, a direct transcriptional activator of CCKN1A (p21WAF1/Cip1), in vitro and in vivo. In addition, we found that DNMT3B specifically methylated the TCF3 promoter, repressing TCF3 expression and accelerating EC cell proliferation independently of EZH2. Importantly, elevated expression of EZH2 or DNMT3B in EC patients inversely correlated with expression of TCF3 and p21, and was associated with shorter overall survival. We show that combined treatment with GSK126 and 5-Aza-2d treatment wit synergistically inhibited methyltransferase activity of EZH2 and DNMT3B, resulting in a profound block of EC cell proliferation as well as EC tumor progression in cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) mouse models. These findings reveal that TCF3 functions as a tumor suppressor epigenetically silenced by EZH2 and DNMT3B in EC, and support the notion that targeting the EZH2/DNMT3B/TCF3/p21 axis may be a novel and effective therapeutic strategy for treatment of EC.

5.
FASEB J ; 35(7): e21706, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34160104

RESUMO

Acute kidney injury (AKI) is a devastating condition with high morbidity and mortality rates. The pathological features of AKI are tubular injury, infiltration of inflammatory cells, and impaired vascular integrity. Pyruvate kinase is the final rate-limiting enzyme in the glycolysis pathway. We previously showed that pyruvate kinase M2 (PKM2) plays an important role in regulating the glycolytic reprogramming of fibroblasts in renal interstitial fibrosis. The present study aimed to determine the role of PKM2 in fibroblast activation during the pathogenesis of AKI. We found increased numbers of S100A4 positive cells expressing PKM2 in renal tissues from mice with AKI induced via folic acid or ischemia/reperfusion (I/R). The loss of PKM2 in fibroblasts impaired fibroblast proliferation and promoted tubular epithelial cell death including apoptosis, necroptosis, and ferroptosis. Mechanistically, fibroblasts produced less hepatocyte growth factor (HGF) in response to a loss of PKM2. Moreover, in two AKI mouse models, fibroblast-specific deletion of PKM2 blocked HGF signal activation and aggravated AKI after it was induced in mice via ischemia or folic acid. Fibroblast proliferation mediated by PKM2 elicits pro-survival signals that repress tubular cell death and may help to prevent AKI progression. Fibroblast activation mediated by PKM2 in AKI suggests that targeting PKM2 expression could be a novel strategy for treating AKI.


Assuntos
Injúria Renal Aguda/metabolismo , Proliferação de Células/fisiologia , Sobrevivência Celular/fisiologia , Células Epiteliais/metabolismo , Fibroblastos/metabolismo , Piruvato Quinase/metabolismo , Animais , Apoptose/fisiologia , Morte Celular/fisiologia , Linhagem Celular , Modelos Animais de Doenças , Fibrose/metabolismo , Fator de Crescimento de Hepatócito/metabolismo , Rim/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Necroptose/fisiologia , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/fisiologia
6.
Front Microbiol ; 12: 642559, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33936000

RESUMO

The rapid diagnosis of tuberculosis (TB) is of great significance for the control and treatment of TB. However, TB remains a major healthy, social, and economic burden worldwide because of the lack of ideal diagnostic biomarkers. Mycobacterium tuberculosis (M. tuberculosis)-encoded small RNA (sRNA) is a class of regulation small RNA. Several studies have identified M. tuberculosis encoded-sRNAs in the serum/plasm of M. tuberculosis-infected patients. Small extracellular vesicles are small membrane vesicles secreted by many cell types during physiological and pathological conditions. Recent evidence has indicated that most of the nucleic acids in the serum/plasma are packaged in the small extracellular vesicles and could serve as ideal diagnostic biomarkers. In this study, we attempted a novel approach for TB diagnosis: targeting small extracellular vesicles M. tuberculosis encoded sRNA (sRNA) by qRT-PCR. The results showed that M. tuberculosis-encoded ASdes and MTB-miR5 only existed in tuberculosis patients and have the potential to serve as a sensitive and accurate methodology for TB diagnosis.

7.
J Clin Invest ; 131(10)2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-33998601

RESUMO

Dachshund homolog 1 (DACH1), a key cell-fate determinant, regulates transcription by DNA sequence-specific binding. We identified diminished Dach1 expression in a large-scale screen for mutations that convert injury-resistant podocytes into injury-susceptible podocytes. In diabetic kidney disease (DKD) patients, podocyte DACH1 expression levels are diminished, a condition that strongly correlates with poor clinical outcomes. Global Dach1 KO mice manifest renal hypoplasia and die perinatally. Podocyte-specific Dach1 KO mice, however, maintain normal glomerular architecture at baseline, but rapidly exhibit podocyte injury after diabetes onset. Furthermore, podocyte-specific augmentation of DACH1 expression in mice protects from DKD. Combined RNA sequencing and in silico promoter analysis reveal conversely overlapping glomerular transcriptomic signatures between podocyte-specific Dach1 and Pax transactivation-domain interacting protein (Ptip) KO mice, with upregulated genes possessing higher-than-expected numbers of promoter Dach1-binding sites. PTIP, an essential component of the activating histone H3 lysine 4 trimethylation (H3K4Me3) complex, interacts with DACH1 and is recruited by DACH1 to its promoter-binding sites. DACH1-PTIP recruitment represses transcription and reduces promoter H3K4Me3 levels. DACH1 knockdown in podocytes combined with hyperglycemia triggers target gene upregulation and increases promoter H3K4Me3. These findings reveal that in DKD, diminished DACH1 expression enhances podocyte injury vulnerability via epigenetic derepression of its target genes.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Diabetes Mellitus Experimental/metabolismo , Nefropatias Diabéticas/prevenção & controle , Proteínas do Olho/biossíntese , Histonas/metabolismo , Podócitos/metabolismo , Animais , Proteínas de Ligação a DNA/genética , Diabetes Mellitus Experimental/genética , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Proteínas do Olho/genética , Histonas/genética , Camundongos , Camundongos Knockout , Podócitos/patologia
8.
Nat Commun ; 12(1): 3229, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-34050181

RESUMO

Radiotherapy (RT)-induced tumoricidal immunity is severely limited when tumors are well-established. Here, we report that depleting SIRPα on intratumoral macrophages augments efficacy of RT to eliminate otherwise large, treatment-resistant colorectal (MC38) and pancreatic (Pan02 and KPC) tumors, inducing complete abscopal remission and long-lasting humoral and cellular immunity that prevent recurrence. SIRPα-deficient macrophages activated by irradiated tumor-released DAMPs exhibit robust efficacy and orchestrate an anti-tumor response that controls late-stage tumors. Upon RT-mediated activation, intratumoral SIRPα-deficient macrophages acquire potent proinflammatory features and conduct immunogenic antigen presentation that confer a tumoricidal microenvironment highly infiltrated by tumor-specific cytotoxic T cells, NK cells and inflammatory neutrophils, but with limited immunosuppressive regulatory T cells, myeloid derived suppressor cells and post-radiation wound-healing. The results demonstrate that SIRPα is a master regulator underlying tumor resistance to RT and provide proof-of-principle for SIRPα-deficient macrophage-based therapies to treat a broad spectrum of cancers, including those at advanced stages with low immunogenicity and metastases.


Assuntos
Neoplasias/terapia , Tolerância a Radiação/imunologia , Receptores Imunológicos/metabolismo , Linfócitos T Citotóxicos/imunologia , Macrófagos Associados a Tumor/imunologia , Alarminas/imunologia , Alarminas/metabolismo , Alarminas/efeitos da radiação , Animais , Apresentação do Antígeno , Antígenos de Neoplasias/imunologia , Antígenos de Neoplasias/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Humanos , Imunoterapia/métodos , Masculino , Camundongos , Camundongos Knockout , Neoplasias/imunologia , Neoplasias/patologia , Estudo de Prova de Conceito , Receptores Imunológicos/genética , Microambiente Tumoral/imunologia , Microambiente Tumoral/efeitos da radiação , Macrófagos Associados a Tumor/metabolismo , Macrófagos Associados a Tumor/transplante
9.
Nat Commun ; 12(1): 2030, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33795678

RESUMO

Microglia play a key role in regulating synaptic remodeling in the central nervous system. Activation of classical complement pathway promotes microglia-mediated synaptic pruning during development and disease. CD47 protects synapses from excessive pruning during development, implicating microglial SIRPα, a CD47 receptor, in synaptic remodeling. However, the role of microglial SIRPα in synaptic pruning in disease remains unclear. Here, using conditional knock-out mice, we show that microglia-specific deletion of SIRPα results in decreased synaptic density. In human tissue, we observe that microglial SIRPα expression declines alongside the progression of Alzheimer's disease. To investigate the role of SIRPα in neurodegeneration, we modulate the expression of microglial SIRPα in mouse models of Alzheimer's disease. Loss of microglial SIRPα results in increased synaptic loss mediated by microglia engulfment and enhanced cognitive impairment. Together, these results suggest that microglial SIRPα regulates synaptic pruning in neurodegeneration.


Assuntos
Doença de Alzheimer/genética , Modelos Animais de Doenças , Microglia/metabolismo , Plasticidade Neuronal/genética , Receptores Imunológicos/genética , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/metabolismo , Animais , Células Cultivadas , Disfunção Cognitiva/genética , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/fisiopatologia , Feminino , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Microglia/citologia , Receptores Imunológicos/metabolismo , Sinapses/metabolismo , Sinapses/fisiologia
10.
Genome Biol ; 22(1): 104, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33849634

RESUMO

BACKGROUND: Although using a blockade of programmed death-ligand 1 (PD-L1) to enhance T cell immune responses shows great promise in tumor immunotherapy, the immune-checkpoint inhibition strategy is limited for patients with solid tumors. The mechanism and efficacy of such immune-checkpoint inhibition strategies in solid tumors remains unclear. RESULTS: Employing qRT-PCR, Sanger sequencing, and RNA BaseScope analysis, we show that human lung adenocarcinoma (LUAD) all produce a long non-coding RNA isoform of PD-L1 (PD-L1-lnc) by alternative splicing, regardless if the tumor is positive or negative for the protein PD-L1. Similar to PD-L1 mRNA, PD-L1-lnc in various lung adenocarcinoma cells is significantly upregulated by IFNγ. Both in vitro and in vivo studies demonstrate that PD-L1-lnc increases proliferation and invasion but decreases apoptosis of lung adenocarcinoma cells. Mechanistically, PD-L1-lnc promotes lung adenocarcinoma progression through directly binding to c-Myc and enhancing c-Myc transcriptional activity. CONCLUSIONS: In summary, the PD-L1 gene can generate a long non-coding RNA through alternative splicing to promote lung adenocarcinoma progression by enhancing c-Myc activity. Our results argue in favor of investigating PD-L1-lnc depletion in combination with PD-L1 blockade in lung cancer therapy.

11.
Genome Med ; 13(1): 58, 2021 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-33853662

RESUMO

BACKGROUND: Aberrant changes in epigenetic mechanisms such as histone modifications play an important role in cancer progression. PRMT1 which triggers asymmetric dimethylation of histone H4 on arginine 3 (H4R3me2a) is upregulated in human colorectal cancer (CRC) and is essential for cell proliferation. However, how this dysregulated modification might contribute to malignant transitions of CRC remains poorly understood. METHODS: In this study, we integrated biochemical assays including protein interaction studies and chromatin immunoprecipitation (ChIP), cellular analysis including cell viability, proliferation, colony formation, and migration assays, clinical sample analysis, microarray experiments, and ChIP-Seq data to investigate the potential genomic recognition pattern of H4R3me2s in CRC cells and its effect on CRC progression. RESULTS: We show that PRMT1 and SMARCA4, an ATPase subunit of the SWI/SNF chromatin remodeling complex, act cooperatively to promote colorectal cancer (CRC) progression. We find that SMARCA4 is a novel effector molecule of PRMT1-mediated H4R3me2a. Mechanistically, we show that H4R3me2a directly recruited SMARCA4 to promote the proliferative, colony-formative, and migratory abilities of CRC cells by enhancing EGFR signaling. We found that EGFR and TNS4 were major direct downstream transcriptional targets of PRMT1 and SMARCA4 in colon cells, and acted in a PRMT1 methyltransferase activity-dependent manner to promote CRC cell proliferation. In vivo, knockdown or inhibition of PRMT1 profoundly attenuated the growth of CRC cells in the C57BL/6 J-ApcMin/+ CRC mice model. Importantly, elevated expression of PRMT1 or SMARCA4 in CRC patients were positively correlated with expression of EGFR and TNS4, and CRC patients had shorter overall survival. These findings reveal a critical interplay between epigenetic and transcriptional control during CRC progression, suggesting that SMARCA4 is a novel key epigenetic modulator of CRC. Our findings thus highlight PRMT1/SMARCA4 inhibition as a potential therapeutic intervention strategy for CRC. CONCLUSION: PRMT1-mediated H4R3me2a recruits SMARCA4, which promotes colorectal cancer progression by enhancing EGFR signaling.

12.
Cell Res ; 31(6): 631-648, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33782530

RESUMO

RNAi therapy has undergone two stages of development, direct injection of synthetic siRNAs and delivery with artificial vehicles or conjugated ligands; both have not solved the problem of efficient in vivo siRNA delivery. Here, we present a proof-of-principle strategy that reprogrammes host liver with genetic circuits to direct the synthesis and self-assembly of siRNAs into secretory exosomes and facilitate the in vivo delivery of siRNAs through circulating exosomes. By combination of different genetic circuit modules, in vivo assembled siRNAs are systematically distributed to multiple tissues or targeted to specific tissues (e.g., brain), inducing potent target gene silencing in these tissues. The therapeutic value of our strategy is demonstrated by programmed silencing of critical targets associated with various diseases, including EGFR/KRAS in lung cancer, EGFR/TNC in glioblastoma and PTP1B in obesity. Overall, our strategy represents a next generation RNAi therapeutics, which makes RNAi therapy feasible.

13.
J Extracell Vesicles ; 10(3): e12055, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33520119

RESUMO

Secreted microRNAs (miRNAs) are novel endocrine factors that play essential pathological and physiological roles. Here, we report that pancreatic ß cell-released exosomal miR-29 family members (miR-29s) regulate hepatic insulin sensitivity and control glucose homeostasis. Cultured pancreatic islets were shown to secrete miR-29s in response to high levels of free fatty acids (FFAs) in vitro. In vivo, high levels of FFAs, promoted by either high-fat diet (HFD) feeding (physiopathological) or fasting (physiological), increased the secretion of miR-29s into plasma. Intravenous administration of exosomal miR-29s attenuated insulin sensitivity. The overexpression of miR-29s in the ß cells of transgenic (TG) mice promoted the secretion of miR-29s and inhibited the insulin-mediated suppression of glucose output in the liver. We used selective overexpression of traceable heterogenous mutant miR-29s in ß cells to confirm that islet-derived exosomal miR-29s target insulin signalling in the liver and blunt hepatic insulin sensitivity. Moreover, in vivo disruption of miR-29s expression in ß cells reversed HFD-induced insulin resistance. In vitro experiments demonstrated that isolated exosomes enriched in miR-29s inhibited insulin signalling in the liver and increased hepatic glucose production. These results unveil a novel ß cell-derived secretory signal-exosomal miR-29s-and provide insight into the roles of miR-29s in manipulating glucose homeostasis.

14.
Kidney Dis (Basel) ; 7(1): 14-23, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33614730

RESUMO

Background: Stimulated by both microbial and endogenous ligands, toll-like receptors (TLRs) play an important role in the development and progression of renal diseases. Summary: As a highly conserved large family, TLRs have 11 members in humans (TLR1∼TLR11) and 13 members in mouse (TLR1∼TLR13). It has been widely reported that TLR2 and TLR4 signaling, activated by both exogenous and endogenous ligands, promote disease progression in both renal ischemia-reperfusion injury and diabetic nephropathy. TLR4 also vitally functions in CKD and infection-associated renal diseases such as pyelonephritis induced by urinary tract infection. Stimulation of intracellular TLR7/8 and TLR9 by host-derived nucleic acids also plays a key role in systemic lupus erythematosus. Given that certain microRNAs with GU-rich sequence have recently been found to be able to serve as TLR7/8 ligands, these microRNAs may initiate pro-inflammatory signal via activating TLR signal. Moreover, as microRNAs can be transferred across different organs via cell-secreted exosomes or protein-RNA complex, the TLR signaling activated by the miRNAs released by other injured organs may also result in renal dysfunction. Key Messages: In this review, we sum up the recent progress in the role of TLRs in various forms of glomerulonephritis and discuss the possible prevention or therapeutic strategies for clinic treatment to renal diseases.

15.
Genomics ; 113(1 Pt 2): 664-676, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33010388

RESUMO

Although the prevalence of inflammatory bowel disease (IBD) has been increasing worldwide, the etiology remains elusive. Investigating oral microbiota dysbiosis is essential to understanding IBD pathogenesis. Our study evaluated variations in salivary microbiota and identified potential associations with IBD. The saliva microbiota of 22 IBD patients and 8 healthy controls (HCs) was determined using 16S ribosomal RNA (rRNA) gene sequencing and analyzed using QIIME2. A distinct saliva microbiota dysbiosis in IBD, characterized by alterations in microbiota biodiversity and composition, was identified. Saccharibacteria (TM7), Absconditabacteria (SR1), Leptotrichia, Prevotella, Bulleidia, and Atopobium, some of which are oral biofilm-forming bacteria, were significantly increased. Moreover, levels of inflammatory cytokines associated with IBD were elevated and positively correlated with TM7 and SR1. Functional variations include down-regulation of genetic information processing, while up-regulation of carbohydrate metabolism and protein processing in the endoplasmic reticulum in IBD. Our data implicate salivary microbiota dysbiosis involving in IBD pathogenesis.

16.
Cell Res ; 31(3): 247-258, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32801357

RESUMO

Dietary microRNAs have been shown to be absorbed by mammals and regulate host gene expression, but the absorption mechanism remains unknown. Here, we show that SIDT1 expressed on gastric pit cells in the stomach is required for the absorption of dietary microRNAs. SIDT1-deficient mice show reduced basal levels and impaired dynamic absorption of dietary microRNAs. Notably, we identified the stomach as the primary site for dietary microRNA absorption, which is dramatically attenuated in the stomachs of SIDT1-deficient mice. Mechanistic analyses revealed that the uptake of exogenous microRNAs by gastric pit cells is SIDT1 and low-pH dependent. Furthermore, oral administration of plant-derived miR2911 retards liver fibrosis, and this protective effect was abolished in SIDT1-deficient mice. Our findings reveal a major mechanism underlying the absorption of dietary microRNAs, uncover an unexpected role of the stomach and shed light on developing small RNA therapeutics by oral delivery.

17.
Kidney Dis (Basel) ; 6(6): 422-433, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33313063

RESUMO

Background: Levels of urinary microvesicles, which are increased during various kidney injuries, have diagnostic potential for renal diseases. However, the significance of urinary microvesicles as a renal disease indicator is dampened by the difficulty to ascertain their cell source. Objectives: The aim of this study was to demonstrate that podocytes can release migrasomes, a unique class of microvesicle with size ranging between 400 and 2,000 nm, and the urine level of migrasomes may serve as novel non-invasive biomarker for early podocyte injury. Method: In this study, immunofluorescence labeling, electronic microscopy, nanosite, and sequential centrifugation were used to purify and analyze migrasomes. Results: Migrasomes released by podocytes differ from exosomes as they have different content and mechanism of release. Compared to podocytes, renal tubular cells secrete markedly less migrasomes. Moreover, secretion of migrasomes by human or murine podocytes was strongly augmented during podocyte injuries induced by LPS, puromycin amino nucleoside (PAN), or a high concentration of glucose (HG). LPS, PAN, or HG-induced podocyte migrasome release, however, was blocked by Rac-1 inhibitor. Strikingly, a higher level of podocyte migrasomes in urine was detected in mice with PAN-nephropathy than in control mice. In fact, increased urinary migrasome number was detected earlier than elevated proteinuria during PAN-nephropathy, suggesting that urinary migrasomes are a more sensitive podocyte injury indicator than proteinuria. Increased urinary migrasome number was also detected in diabetic nephropathy patients with proteinuria level <5.5 g/day. Conclusions: Our findings reveal that podocytes release the "injury-related" migrasomes during migration and provide urinary podocyte migrasome as a potential diagnostic marker for early podocyte injury.

18.
Kidney Int ; 98(3): 686-698, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32739207

RESUMO

Energy reprogramming to glycolysis is closely associated with the development of chronic kidney disease. As an important negative regulatory factor of the mammalian target of rapamycin complex 1 (mTORC1) signal, tuberous sclerosis complex 1 (Tsc1) is also a key regulatory point of glycolysis. Here, we investigated whether Tsc1 could mediate the progression of kidney interstitial fibrosis by regulating glycolysis in proximal tubular epithelial cells. We induced mTORC1 signal activation in tubular epithelial cells in kidneys with fibrosis via unilateral ureteral occlusion. This resulted in increased tubular epithelial cell proliferation and glycolytic enzyme upregulation. Prior incubation with rapamycin inhibited mTORC1 activation and abolished the enhanced glycolysis and tubular epithelial cell proliferation. Furthermore, knockdown of Tsc1 expression promoted glycolysis in the rat kidney epithelial cell line NRK-52E. Specific deletion of Tsc1 in the proximal tubules of mice resulted in enlarged kidneys characterized by a high proportion of proliferative tubular epithelial cells, dilated tubules with cyst formation, and a large area of interstitial fibrosis in conjunction with elevated glycolysis. Treatment of the mice with the glycolysis inhibitor 2-deoxyglucose notably ameliorated tubular epithelial cell proliferation, cystogenesis, and kidney fibrosis. Thus, our findings suggest that Tsc1-associated mTORC1 signaling mediates the progression of kidney interstitial fibrosis by regulating glycolysis in proximal tubular epithelial cells.


Assuntos
Esclerose Tuberosa , Animais , Células Epiteliais , Fibrose , Glicólise , Rim/patologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Ratos , Esclerose Tuberosa/metabolismo , Esclerose Tuberosa/patologia , Proteína 1 do Complexo Esclerose Tuberosa
19.
J Pathol ; 252(2): 165-177, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32686090

RESUMO

Infiltration of activated T cells into renal tissue plays an essential role in inflammatory nephropathy. However, the mechanism enabling the renal recruitment and activation of T cells remains elusive. Here we report that inflammatory cytokine-promoted antigen presentation by podocytes is a key for recruiting and activating specific T cells. Our results showed that diabetes-associated inflammatory cytokines IFNγ and IL-17 all upregulated expression of MHC-I, MHC-II, CD80 and CD86 on the podocyte surface. Both IFNγ and IL-17 stimulated the uptake and processing of ovalbumin (OVA) by mouse podocytes, resulting in presentation of OVA antigen peptide on the cell surface. OVA antigen presentation by podocytes was also validated using human podocytes. Furthermore, OVA antigen-presenting mouse podocytes were able to activate OT-I mouse T cell proliferation and inflammatory cytokine secretion, which in turn caused podocyte injury and apoptosis. Finally, OT-I mice subjected to direct renal injection of OVA plus IFNγ/IL-17 but not OVA alone exhibited OVA antigen presentation by podocytes and developed nephropathy in 4 weeks. In conclusion, antigen presentation by podocytes under inflammatory conditions plays an important role in activating T cell immune responses and facilitating immune-mediated glomerular disease development. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Apresentação do Antígeno/imunologia , Ativação Linfocitária/imunologia , Nefrite/imunologia , Podócitos/imunologia , Linfócitos T/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Humanos , Camundongos
20.
Aging (Albany NY) ; 12(14): 15002-15010, 2020 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-32597791

RESUMO

Changes in expression of long non-coding RNAs (lncRNAs) in plasma exosomes can be useful for diagnosis of cancer patients. Here, we conducted a four-stage study to identify plasma exosome lncRNAs with diagnostic potential in esophageal squamous cell carcinoma (ESCC). First, plasma exosome lncRNA expression profiles were examined in ESCC patients, esophagitis patients, and healthy controls using RNA sequencing. Differentially expressed plasma exosome lncRNAs from the lncRNA expression profile were then evaluated by qRT-PCR in a large cohort of ESCC patients, esophagitis patients, and healthy controls. Expression levels of the lncRNAs NR_039819, NR_036133, NR_003353, ENST00000442416.1, and ENST00000416100.1 were significantly higher in exosomes from ESCC patients than non-cancer controls. We also confirmed that levels of these five plasma exosome lncRNAs decreased markedly in ESCC patients after surgery. Our results suggest that these five exosome lncRNAs may serve as highly effective, noninvasive biomarkers for ESCC diagnosis.


Assuntos
Ácidos Nucleicos Livres/sangue , Esofagite , Exossomos/metabolismo , RNA Longo não Codificante/análise , Adulto , Biomarcadores Tumorais/sangue , Neoplasias Esofágicas/sangue , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/sangue , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/patologia , Esofagite/sangue , Esofagite/genética , Feminino , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Estadiamento de Neoplasias , Análise de Sequência de RNA
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