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AIMS: Renal fibrosis is a common feature in various chronic kidney diseases (CKD). Tubular cell damage is a main characterization which results from dysregulated fatty acid oxidation (FAO) and lipid accumulation. Cannabinoid Receptor 2 (CB2) contributes to renal fibrosis, however, its role in FAO dysregulation in tubular cells is not clarified. In this study, we found CB2 plays a detrimental role in lipid metabolism in tubular cells. METHODS: CB2 knockout mice were adopted to establish a folic acid-induced nephropathy (FAN) model. CB2-induced FAO dysfunction, lipid deposition, and fibrogenesis were assessed in vivo and vitro. To explore molecular mechanisms, ß-catenin inhibitors and peroxisome proliferator-activated receptor alpha (PPARα) activators were also used in CB2-overexpressed cells. The mediative role of ß-catenin in CB2-inhibited PPARα and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) activation was analyzed. RESULTS: CB2 activates ß-catenin signaling, resulting in the suppression of PPARα/PGC-1α axis. This decreased FAO functions and led to lipid droplet formation in tubular cells. CB2 gene ablation effectively mitigated FAO dysfunction, lipid deposition and uremic toxins accumulation in FAN mice, consequently retarding renal fibrosis. Additionally, inhibition to ß-catenin or PPARα activation could greatly inhibit lipid accumulation and fibrogenesis induced by CB2. CONCLUSIONS: This study highlights CB2 disrupts FAO in tubular cells through ß-catenin activation and subsequent inhibition on PPARα/PGC-1α activity. Targeted inhibition on CB2 offers a perspective therapeutic strategy to fight against renal fibrosis.
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Acute kidney injury (AKI) is in high prevalence worldwide but with no therapeutic strategies. Programmed cell death in tubular epithelial cells has been reported to accelerate a variety of AKI, but the major pathways and underlying mechanisms are not defined. Herein, we identified that pyroptosis was responsible for AKI progression and related to ATP depletion in renal tubular cells. We found that FAM3A, a mitochondrial protein that assists ATP synthesis, was decreased and negatively correlated with tubular cell injury and pyroptosis in both mice and patients with AKI. Knockout of FAM3A worsened kidney function decline, increased macrophage and neutrophil cell infiltration, and facilitated tubular cell pyroptosis in ischemia/reperfusion injury model. Conversely, FAM3A overexpression alleviated tubular cell pyroptosis, and inhibited kidney injury in ischemic AKI. Mechanistically, FAM3A promoted PI3K/AKT/NRF2 signaling, thus blocking mitochondrial reactive oxygen species (mt-ROS) accumulation. NLRP3 inflammasome sensed the overload of mt-ROS and then activated Caspase-1, which cleaved GSDMD, pro-IL-1ß, and pro-IL-18 into their mature forms to mediate pyroptosis. Of interest, NRF2 activator alleviated the pro-pyroptotic effects of FAM3A depletion, whereas the deletion of NRF2 blocked the anti-pyroptotic function of FAM3A. Thus, our study provides new mechanisms for AKI progression and demonstrates that FAM3A is a potential therapeutic target for treating AKI.
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Injúria Renal Aguda , Túbulos Renais , Piroptose , Espécies Reativas de Oxigênio , Animais , Humanos , Masculino , Camundongos , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Injúria Renal Aguda/genética , Citocinas , Modelos Animais de Doenças , Inflamassomos/metabolismo , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Camundongos Knockout , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Fator 2 Relacionado a NF-E2/metabolismo , Fator 2 Relacionado a NF-E2/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de SinaisRESUMO
Ecosystem Services Value (ESV) are the various beneficial functions and products that natural ecosystems provide to humans, and are important indicators for evaluating ecosystem conditions and human well-being. Opencast mining is one of the human activities that severely damage the surface environment, but its long-term impact on ecosystem services lacks systematic assessment. This study takes the Ordos opencast mining area as an example, and calculates the value of ESV from 1990 to 2020 based on the Google Earth Engine platform. Mann-Kendall Tau-b with Sen's Method (Sen + mk test) and Joinpoint regression model were used to analyzes its spatiotemporal variation characteristics. Further revealed the impacts of opencast mining on ESV as well as the trend of ESV changes. The results show that: (1) The dynamic ESV levels in the study area fluctuated considerably from 1990 to 2020 with an overall decreasing trend of 89.45%. (2) Among nine types ecosystem services, most of them were significantly different (p < 0.001) between mining areas and control areas, with biodiversity protection (BP), climate regulation (CR), gas regulation (GR), soil formation and retention (SFR), water supply (WS) and waste treatment (WT) showed a significant decrease between 1990 and 2020. (3) In the past 30 years, the ESV of the study area showed an overall improvement trend, where the improved area accounted for 48.45% of the total area of the study area. However, the degraded area also accounted for 21.28, and 17.19% of the area belonged to severe degradation. With 67% of the significantly degraded areas distributed within mining concessions. (4) The trend of ESV changes in the mining impact areas and the control area showed significant differences. The ESV of the control area increased continuously, with an average annual percentage change (AAPC) of 0.7(95%CI:0.50 ~ 0.9, P < 0.001) from 1990 to 2020; while the ESV of the mining impact areas first stabilized and then decreased significantly, with an AAPC of - 0.2(95%CI:- 0.3 ~ - 0.1,P < 0.001) from 1990 to 2020. This study provides scientific support for formulating ecosystem management, restoration plans, and payment for ecosystem service policies, which is conducive to achieving regional sustainable development and improving human well-being.
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Ecossistema , Tecnologia de Sensoriamento Remoto , Humanos , Ferramenta de Busca , Conservação dos Recursos Naturais , SoloRESUMO
Crocetin as one of the main components of saffron possesses a lot of pharmacological effects, especially the beneficial effects in the treatment of hyperlipidemia. However, the pharmacokinetics of crocetin in the pathological state of hyperlipidemia has not been reported. In present study, the pharmacokinetics of crocetin in hyperlipidemia rats after oral administration of crocetin was investigated and the possible mechanisms for the pharmacokinetics were explored. High-fat diet was used to induce hyperlipidemia in rats. The pharmacokinetics of crocetin was investigated in hyperlipidemia and normal rats after oral and intravenous administration of crocetin, and the possible mechanisms of the pharmacokinetic changes were investigated in terms of metabolism and absorption using in vitro incubation with liver microsomes and the everted gut sac method, respectively. Results indicated that the AUCs of crocetin in hyperlipidemia rats after oral administration of crocetin were remarkably decreased when compared with those in normal rats. Moreover, crocetin was also metabolized more rapidly in the liver microsomes of hyperlipidemia rats and intestinal absorption of crocetin was significantly reduced in hyperlipidemia rats. It suggested that the remarkably decreased AUCs of crocetin in hyperlipidemia rats might partly result from the result of faster metabolic elimination and reduced absorption of crocetin in the hyperlipidemia pathological state. And the present investigations conducted on rats demonstrate that further investigations into the kinetics of crocetin in humans with hyperlipidemia are necessary in order to ensure an adequate dosage in this indication.
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Carotenoides , Hiperlipidemias , Microssomos Hepáticos , Ratos Sprague-Dawley , Vitamina A , Animais , Carotenoides/farmacocinética , Carotenoides/administração & dosagem , Vitamina A/análogos & derivados , Vitamina A/administração & dosagem , Hiperlipidemias/tratamento farmacológico , Hiperlipidemias/metabolismo , Masculino , Administração Oral , Microssomos Hepáticos/metabolismo , Ratos , Absorção Intestinal/efeitos dos fármacos , Dieta Hiperlipídica , Área Sob a Curva , Hipolipemiantes/farmacocinética , Hipolipemiantes/administração & dosagemRESUMO
Rationale: Renal fibrosis, with no therapeutic approaches, is a common pathological feature in various chronic kidney diseases (CKD). Tubular cell injury plays a pivotal role in renal fibrosis. Commonly, injured tubular cells exhibit significant lipid accumulation. However, the underlying mechanisms remain poorly understood. Methods: 2-arachidonoylglycerol (2-AG) levels in CKD patients and CKD model specimens were measured using mass spectrometry. 2-AG-loaded nanoparticles were infused into unilateral ureteral obstruction (UUO) mice. Lipid accumulation and renal fibrosis were tested. Furthermore, monoacylglycerol lipase (MAGL), the hydrolyzing enzyme of 2-AG, was assessed in CKD patients and models. Tubular cell-specific MAGL knock-in mice were generated. Moreover, MAGL recombination protein was also administered to unilateral ischemia reperfusion injury (UIRI) mice. Besides, a series of methods including RNA sequencing, metabolomics, primary cell culture, lipid staining, etc. were used. Results: 2-AG was increased in the serum or kidneys from CKD patients and models. Supplement of 2-AG further induced lipid accumulation and fibrogenesis through cannabinoid receptor type 2 (CB2)/ß-catenin signaling. ß-catenin knockout blocked 2-AG/CB2-induced fatty acid ß-oxidation (FAO) deficiency and lipid accumulation. Remarkably, MAGL significantly decreased in CKD, aligning with lipid accumulation and fibrosis. Specific transgene of MAGL in tubular cells significantly preserved FAO, inhibited lipid-mediated toxicity in tubular cells, and finally retarded fibrogenesis. Additionally, supplementation of MAGL in UIRI mice also preserved FAO function, inhibited lipid accumulation, and protected against renal fibrosis. Conclusion: MAGL is a potential diagnostic marker for kidney function decline, and also serves as a new therapeutic target for renal fibrosis through ameliorating lipotoxicity.
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Monoacilglicerol Lipases , Insuficiência Renal Crônica , Animais , Humanos , Camundongos , beta Catenina , Fibrose , RimRESUMO
To bring about a revolution in energy storage through Li-ion batteries, it is crucial to develop a scalable preparation method for Si-based composite anodes. However, the severe volume expansion and poor ionic transport properties of Si-based composites present significant challenges. Previous research focused on SiO and nano Si/C composites to address these issues. In this study, mechanical milling was used to introduce a SiOx layer onto the surface of Si by mixing Si and SiO2 in a 1 : 1 mass ratio. The resulting Si+SiO2 composites (denoted as SS50) exhibited an initial coulombic efficiency (ICE) of 73.5% and high rate performance. To further stabilize the overall structure, kerosene was introduced as a carbon source precursor to generate a coating layer. The resulting multiphase composite structure (SiOx+SiO2+C), designated as SS50-900C, demonstrated a capacity retention of 79.5% over 280 cycles at its capacity of 487 mA h g-1. These results suggest that a cost-effective mechanical ball milling refinement of Si+SiO2 and a gas-phase encapsulation process can significantly improve the electrochemical performance of Si-based composites.
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The prevalence of chronic kidney disease (CKD) is highly increasing. Renal fibrosis is a common pathological feature in various CKD. Previous studies showed tubular cell senescence is highly involved in the pathogenesis of renal fibrosis. However, the inducers of tubular senescence and the underlying mechanisms have not been fully investigated. C-X-C motif chemokine receptor 4 (CXCR4), a G-protein-coupled seven-span transmembrane receptor, increases renal fibrosis and plays an important role in tubular cell injury. Whereas, whether CXCR4 could induce tubular cell senescence and the detailed mechanisms have not studied yet. In this study, we adopted adriamycin nephropathy and 5/6 nephrectomy models, and cultured tubular cell line. Overexpression or knockdown of CXCR4 was obtained by injection of related plasmids. We identified CXCR4 increased in injury tubular cells. CXCR4 was expressed predominantly in renal tubular epithelial cells and co-localized with adipose differentiation-related protein (ADRP) as well as the senescence-related protein P16INK4A . Furthermore, we found overexpression of CXCR4 greatly induced the activation of ß-catenin, while knockdown of CXCR4 inhibited it. We also found that CXCR4 inhibited fatty acid oxidation and triggered lipid deposition in tubular cells. To inhibit ß-catenin by ICG-001, an inhibitor of ß-catenin, could significantly block CXCR4-suppressed fatty acid oxidation. Taken together, our results indicate that CXCR4 is a key mediator in tubular cell senescence and renal fibrosis. CXCR4 promotes tubular cell senescence and renal fibrosis by inducing ß-catenin and inhibiting fatty acid metabolism. Our findings provide a new theory for tubular cell injury in renal fibrosis.
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Rim , Receptores CXCR4 , Insuficiência Renal Crônica , beta Catenina , beta Catenina/metabolismo , Senescência Celular , Células Epiteliais/metabolismo , Ácidos Graxos/metabolismo , Fibrose , Rim/patologia , Insuficiência Renal Crônica/patologia , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Animais , CamundongosRESUMO
Glomeruli stand at the center of nephrons to accomplish filtration and albumin interception. Podocytes and mesangial cells are the major constituents in the glomeruli. However, their interdependency in glomerular injury has rarely been reported. Herein, we investigated the role of C-X-C chemokine receptor type 4 (CXCR4) in mediating the crosstalk between podocytes and mesangial cells. We found CXCR4 and angiotensin II (AngII) increased primarily in injured podocytes. However, type-1 receptor of angiotensin II (AT1) and stromal cell-derived factor 1α (SDF-1α), a ligand of CXCR4, were evidently upregulated in mesangial cells following the progression of podocyte injury. Ectopic expression of CXCR4 in 5/6 nephrectomy mice increased the decline of renal function and glomerular injury, accelerated podocyte injury and mesangial cell activation, and initiated CXCR4-AT1 axis signals. Additionally, treatment with losartan, an AT1 blocker, interrupted the cycle of podocyte injury and mesangial matrix deposition triggered by CXCR4. Podocyte-specific ablation of CXCR4 gene blocked podocyte injury and mesangial cell activation. In vitro, CXCR4 overexpression induced oxidative stress and renin angiotensin system (RAS) activation in podocytes, and triggered the communication between podocytes and mesangial cells. In cultured mesangial cells, AngII treatment induced the expression of SDF-1α, which was secreted into the supernatant to further promote oxidative stress and cell injury in podocytes. Collectively, these results demonstrate that the CXCR4-AT1 axis plays a vital role in glomerular injury via mediating pathologic crosstalk between podocytes and mesangial cells. Our findings uncover a novel pathogenic mechanism by which the CXCR4-AT1 axis promotes glomerular injury.
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Podócitos , Animais , Camundongos , Angiotensina II/farmacologia , Quimiocina CXCL12/metabolismo , Glomérulos Renais/patologia , Células Mesangiais/metabolismo , Podócitos/metabolismo , Podócitos/patologiaRESUMO
Building a carbon ecological security (CES) framework helps to scientifically evaluate and manage the regional carbon cycle and eco-environment and support regional ecological security patterns. This paper adopted the pressure-state-response-immune (PSRI) model and the carbon balance index method to evaluate the ecological quality and carbon balance pressure. Then, based on the decoupling model and the improved four-quadrant model, the CES framework was constructed to evaluate the changing trend of the CES of Xuzhou City from 2005 to 2020. The results showed that the carbon balance pressure of Xuzhou City showed a pattern of "low-high-low" from east to west, and most areas tended to have a carbon balance and surplus in 2020. The ecological quality showed an overall upward trend during the study period. Protection and restoration drove the response and immune index growth from 2010 to 2020. In the Thirteenth Five-Year Plan stage, the nine districts of Xuzhou City were in a stable decoupling state, and the overall decoupling process was ideal. The CES of districts showed individual differences in the general upward trend. The carbon balance pressure of Gulou and Quanshan Districts was the main factor restricting the districts' CES. Therefore, based on the empirical results, this research proposes relevant suggestions to enhance carbon ecological security to achieve regional green and low-carbon development.
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Ecologia , Ecossistema , Ecologia/métodos , Conservação dos Recursos Naturais/métodos , Modelos Teóricos , Cidades , China , CarbonoRESUMO
Acute kidney injury (AKI) is rapidly increasing nowadays and at a high risk to progress into chronic kidney disease (CKD). Of note, men are more susceptive to AKI, suggesting gender differences in AKI patients. However, the underlying mechanisms remain largely unclear. To test it, we adopted two experimental models of AKI, including ischemia/reperfusion injury and rhabdomyolysis, which were constructed in age-matched male and female mice. We found severe damages of tubular apoptosis, mitochondrial dysfunction, and loss of renal function showing in male mice, while female mice only had very mild injury. We further tested the expression of Sirtuins, and found that female mice could preserve more Sirtuin members' expression in case of kidney damage. Among Sirtuin family, Sirtuin 6 was maximally preserved in injured kidney in female mice, suggesting its important role involved in the gender differences of AKI pathogenesis. We then found that knockdown of androgen receptor (AR) attenuated tubular damage, mitochondrial dysfunction and retarded the loss of renal function. Overexpression of Sirtuin 6 also showed similar results. Furthermore, in cultured tubular cells, dihydrotestosterone (DHT) decreased Sirtuin 6 expression and exacerbated cell apoptosis. Ectopic expression of Sirtuin 6 sufficiently inhibited DHT-induced cell apoptosis. Mechanically, we found AR inhibited Sirtuin 6, leading to the repression of binding of Sirtuin 6 with PGC-1α. This resulted in acetylation of PGC-1α and inhibition of its activity, further triggered the loss of mitochondrial homeostasis. Our results provided new insights to the underlying mechanisms of gender differences in AKI, suggesting Sirtuin 6 maybe a new therapeutic target for preventing AKI in male patients.
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Background: Liver kinase B1 (LKB1) is the key regulator of energy metabolism and cell homeostasis. LKB1 dysfunction plays a key role in renal fibrosis. However, LKB1 activators are scarce in commercial nowadays. This study aims to discover a new drug molecule, piericidin analogue S14 (PA-S14), preventing renal fibrosis as a novel activator to LKB1. Methods: Our group isolated PA-S14 from the broth culture of a marine-derived Streptomyces strain and identified its binding site. We adopted various CKD models or AKI-CKD model (5/6 nephrectomy, UUO, UIRI and adriamycin nephropathy models). TGF-ß-stimulated renal tubular cell culture was also tested. Results: We identified that PA-S14 binds with residue D176 in the kinase domain of LKB1, and then induces the activation of LKB1 through its phosphorylation and complex formation with MO25 and STRAD. As a result, PA-S14 promotes AMPK activation, triggers autophagosome maturation, and increases autophagic flux. PA-S14 inhibited tubular cell senescence and retarded fibrogenesis through activation of LKB1/AMPK signaling. Transcriptomics sequencing and mutation analysis further demonstrated our results. Conclusion: PA-S14 is a novel leading compound of LKB1 activator. PA-S14 is a therapeutic potential to renal fibrosis through LKB1/AMPK-mediated autophagy and mitochondrial homeostasis pathways.
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Proteínas Quinases Ativadas por AMP , Insuficiência Renal Crônica , Humanos , Proteínas Quinases Ativadas por AMP/metabolismo , Quinases Proteína-Quinases Ativadas por AMP , Autofagia , Células Epiteliais/metabolismo , Fibrose , Homeostase , Doxorrubicina , Fator de Crescimento Transformador betaRESUMO
Acute kidney injury (AKI) is in high prevalence in the world. However, the therapeutic strategies for AKI are still in mystery. Studies have shown to improve autophagy and lysosomal function could inhibit AKI. But their modulators need to be explored in detail. Annexin A2 (ANXA2) is a phospholipid-binding protein involving in organelle membrane integrity function, suggesting its important role in autophagy and lysosome homeostasis. It implicates ANXA2 potentially protects against AKI. However, this has not been elucidated. Herein, we found that ANXA2 is increased in renal tubules in cisplatin-induced AKI mice. Ectopic expression of ANXA2 improved lysosomal functions and enhanced autophagic flux, further protecting against renal tubular cell apoptosis and kidney injury. Conversely, knockdown of ANXA2 inhibited lysosomal function and autophagy, which aggravated the progression of AKI. Transcriptome sequencing revealed ß-catenin signaling is highly responsible for this process. In vitro, we found ANXA2 induced ß-catenin activation, further triggering T-cell factor-4 (TCF4)-induced transcription factor EB (TFEB). Furthermore, TFEB promoted lysosome biogenesis to enhance autophagic flux, resulting in the alleviation of AKI. Our new findings underline ANXA2 is a new therapeutic potential for AKI through modulating autophagy and lysosomal function. The underlying mechanism is associated with its inductive effects on ß-catenin/TFEB pathway.
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Simple, rapid and sensitive analysis of drug-derived pollutants is critically valuable for environmental monitoring. Here, taking acetaminophen, hydroquinone and catechol as a study example, a sensor based on an ITO/APTES/r-GO@Au electrode was developed for separate and simultaneous determination of phenolic pollutants. ITO electrodes that are modified with 3-aminopropyltriethoxysilane (APTES), graphene (GO) and Au nanoparticles (Au NPs) can significantly enhance the electronic transport of phenolic pollutants at the electrode surface. The redox mechanisms of phenolic pollutants include the electron transfer with the enhancement of r-GO@Au. The modified ITO electrode exhibits excellent electrical properties to phenolic pollutants and a good linear relationship between ECL intensity and the concentration of phenolic pollutants, with a limit of detection of 0.82, 1.41 and 1.95 µM, respectively. The separate and simultaneous determination of AP, CC and HQ is feasible with the ITO/APTES/r-GO@Au electrode. The sensor shows great promise as a low-lost, sensitive, and rapid method for simultaneous determination of drug-derived pollutants.
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Pyrrolizidine alkaloids (PAs) and PA N-oxides are hepatotoxic natural products, produced by over 6000 plant species worldwide. However, an unmet need remains for confirmative measurement of PAs in routine clinical tests. Here, we develop a visual, easy-to-use, and economic mesoporous silica-electrochemiluminescence (MPS-ECL) sensor for point-of-care (POC) testing of PAs, utilizing MPS's amplification effect on positive ions. The relationship between PAs' different structures and corresponding Ru(bpy)32+ ECL activity shows that reaction mechanism, stability of intermediate, molecular geometry and alternative anodic reactivity significantly affect the ECL activity. The ECL intensity varies among different PAs: monocrotaline Ë senecionine N-oxide Ë retrorsine Ë senkirkine. The POC sensors possess excellent linearity (0.9993 > R2 > 0.9944), low detection limits (0.02 µM-0.07 µM), and good recoveries (90.12%-105.93%), indicating good accuracy and practicability. The portable and low-cost sensor is user-friendly, which holds promise to be applied to POC testing of PAs in drugs, food products, and clinical samples, which is promising for initial assessments of PA-induced health risk.
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Sistemas Automatizados de Assistência Junto ao Leito , Alcaloides de Pirrolizidina , Monocrotalina , Óxidos/química , Alcaloides de Pirrolizidina/química , Alcaloides de Pirrolizidina/farmacologiaRESUMO
Podocyte injury is a hallmark of glomerular diseases; however, the underlying mechanisms remain unclear. B7-1 is increased in injured podocytes, but its intrinsic role is controversial. The clinical data here revealed the intimate correlation of urinary B7-1 with severity of glomerular injury. Through transcriptomic and biological assays in B7-1 transgenic and adriamycin nephropathy models, we identified B7-1 is a key mediator in podocyte injury and glomerulosclerosis through a series of signal transmission to ß-catenin. Using LC-MS/MS, Hsp90ab1, a conserved molecular chaperone, was distinguished to be an anchor for transmitting signals from B7-1 to ß-catenin. Molecular docking and subsequent mutant analysis further identified the residue K69 in the N terminal domain of Hsp90ab1 was the key binding site for B7-1 to activate LRP5/ß-catenin pathway. The interaction and biological functions of B7-1-Hsp90ab1-LRP5 complex were further demonstrated in vitro and in vivo. We also found B7-1 is a novel downstream target of ß-catenin. Our results indicate an intercrossed network of B7-1, which collectively induces podocyte injury and glomerulosclerosis. Our study provides an important clue to improve the therapeutic strategies to target B7-1.
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Nefropatias , Podócitos , Humanos , beta Catenina/genética , beta Catenina/metabolismo , Cromatografia Líquida , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Nefropatias/metabolismo , Proteína-5 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Chaperonas Moleculares/metabolismo , Simulação de Acoplamento Molecular , Podócitos/metabolismo , Espectrometria de Massas em TandemRESUMO
Ru(bpy)3Cl2/TPrA is a prominent and widely used ECL system in analytical science. However, the co-reactant TPrA restricts the variety of applications because of its toxicity, volatility, and high cost. Here, we use arginine (Arg) as an alternative co-reactant for Ru(bpy)3 2+ by taking advantage of its low cost, non-toxicity, and biocompatibility. The mechanism of the Ru(bpy)3 2+/Arg system is that the deprotonated Arg can react with Ru(bpy)3 2+ to release emission. The similarity between the Ru(bpy)3 2+/Arg, Ru(bpy)3 2+/TPrA, and Ru(bpy)3 2+/DBAE systems demonstrates that Arg can be used as an alternative co-reactant for Ru(bpy)3 2+ ECL. As a proof of concept, we achieve an excellent performance for acetaminophen (Ace) detection based on the specificity of Arg and Ace, with excellent linearity, low detection limits, and good recoveries. This work is promising to expand the scope of the Ru(bpy)3 2+/Arg system and move forward their applications in bioassays.
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Aging is an important risk factor for kidney injury. Energy homeostasis plays a key role in retarding aging, and mitochondria are responsible for energy production. In the kidney, renal tubular cells possess high abundance of mitochondria to meet the high energy consumption. AMPK is an evolutionarily conserved serine/threonine kinase which plays a central role in maintaining energy homeostasis and mitochondrial homeostasis. Besides that, AMPK also commands autophagy, a clearing and recycling process to maintain cellular homeostasis. However, the effect of AMPK activators on kidney aging has not been fully elucidated. To this end, we testified the effects of O304, a novel direct AMPK activator, in naturally aging mice model and D-Galactose (D-Gal)-treated renal tubular cell culture. We identified that O304 beneficially protects against cellular senescence and aged-related fibrosis in kidneys. Also, O304 restored energy metabolism, promoted autophagy and preserved mitochondrial homeostasis. Transcriptomic sequencing also proved that O304 induced fatty acid metabolism, mitochondrial biogenesis and ATP process, and downregulated cell aging, DNA damage response and collagen organization. All these results suggest that O304 has a strong potential to retard aged kidney injury through regulating AMPK-induced multiple pathways. Our results provide an important therapeutic approach to delay kidney aging.
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Kidney is one of the most important organs in maintaining the normal life activities. With the high abundance of mitochondria, renal tubular cell plays the vital role in functioning in the reabsorption and secretion of kidney. Reports have shown that mitochondrial dysfunction is of great importance to renal tubular cell senescence and subsequent kidney ageing. However, the underlying mechanisms are not elucidated. Cannabinoid receptor 2 is one of the two receptors responsible for the activation of endocannabinoid system. CB2 is primarily upregulated in renal tubular cells in chronic kidney diseases and mediates fibrogenesis. However, the role of CB2 in tubular mitochondrial dysfunction and kidney ageing has not been clarified. In this study, we found that CB2 was upregulated in kidneys in 24-month-old mice and d-galactose (d-gal)-induced accelerated ageing mice, accompanied by the decrease in mitochondrial mass. Furthermore, gene deletion of CB2 in d-gal-treated mice could greatly inhibit the activation of ß-catenin signalling and restore the mitochondrial integrity and Adenosine triphosphate (ATP) production. In CB2 knockout mice, renal tubular cell senescence and kidney fibrosis were also significantly inhibited. CB2 overexpression or activation by the agonist AM1241 could sufficiently induce the decrease in PGC-1α and a variety of mitochondria-related proteins and trigger cellular senescence in cultured human renal proximal tubular cells. CB2-activated mitochondrial dysfunction and cellular senescence could be blocked by ICG-001, a blocker for ß-catenin signalling. These results show CB2 plays a central role in renal tubular mitochondrial dysfunction and kidney ageing. The intrinsic mechanism may be related to its activation in ß-catenin signalling.
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Senescência Celular , Rim , Mitocôndrias/metabolismo , Receptor CB2 de Canabinoide/fisiologia , beta Catenina/metabolismo , Animais , Linhagem Celular , Células Epiteliais , Humanos , Rim/metabolismo , Rim/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Insuficiência Renal Crônica/metabolismoRESUMO
Chronic kidney disease (CKD) has a high prevalence worldwide and is an intricate issue to whole medical society. Renal fibrosis is the common pathological feature for various kinds of CKD. As an anti-aging protein, Klotho is predominantly expressed in renal tubular epithelial cells. Reports show Klotho could retard age-related renal fibrosis. Mitochondrial dysfunction plays an important role in cellular senescence. However, the role of Klotho in mitochondrial dysfunction in CKD has not yet been determined. In this study, we treated unilateral ischemia-reperfusion (UIRI) mice and cultured human renal tubular epithelial cells (HKC-8) with Klotho. We assessed renal fibrosis, cellular senescence, and Wnt/ß-catenin signaling. We also focused on mitochondrial function assessment. In UIRI mice, ectopic expression of Klotho greatly retarded fibrotic lesions and the activation of Wnt/ß-catenin signaling. Interestingly, Klotho significantly preserved mitochondrial mass, inhibited mitochondrial reactive oxygen species (ROS) production and restored the expression of mitochondrial respiration chain complex subunits. Consequently, Klotho restrained cellular senescence. In HKC-8 cells, Klotho significantly inhibited Wnt1- and Wnt9a-induced mitochondrial injury, cellular senescence, and fibrotic lesions. These results suggest Klotho has a protective role in renal function through targeted protection on mitochondria. This further broads the understanding of the beneficial efficacies of Klotho in CKD.
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Túbulos Renais Proximais/efeitos dos fármacos , Proteínas Klotho/administração & dosagem , Proteínas Klotho/metabolismo , Mitocôndrias/efeitos dos fármacos , Insuficiência Renal Crônica/tratamento farmacológico , Traumatismo por Reperfusão/tratamento farmacológico , Via de Sinalização Wnt/efeitos dos fármacos , Animais , Senescência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Fibrose , Humanos , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Cultura Primária de Células , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/patologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologiaRESUMO
The endocannabinoid system has multiple effects. Through interacting with cannabinoid receptor type 1 and type 2, this system can greatly affect disease progression. Previously, we showed that activated cannabinoid receptor type 2 (CB2) mediated kidney fibrosis. However, the underlying mechanisms remain underdetermined. Here, we report that CB2 was upregulated predominantly in kidney tubular epithelial cells in unilateral urinary obstruction and ischemia-reperfusion injury models in mice, and in patients with a variety of kidney diseases. CB2 expression was closely correlated with the progression of kidney fibrosis and accompanied by the activation of ß-catenin. Furthermore, CB2 induced the formation of a ß-arrestin 1/Src/ß-catenin complex, which further triggered the nuclear translocation of ß-catenin and caused fibrotic injury. Incubation with XL-001, an inverse agonist to CB2, or knockdown of ß-arrestin 1 inhibited CB2-triggered activation of ß-catenin and fibrotic injury. Notably, CB2 potentiated Wnt1-induced ß-arrestin 1/ß-catenin activation and augmented the pathogenesis of kidney fibrosis in mice with unilateral ischemia-reperfusion injury or folic acid-induced nephropathy. Knockdown of ß-arrestin 1 inhibited the CB2 agonist AM1241-induced ß-catenin activation and kidney fibrosis. By promoter sequence analysis, putative transcription factor binding sites for T-cell factor/lymphoid enhancer factor were found in the promoter regions of the CB2 gene regardless of the species. Overexpression of ß-catenin induced the binding of T-cell factor/lymphoid enhancer factor-1 to these sites, promoted the expression of CB2, ß-arrestin 1, and the proto-oncogene Src, and triggered their accumulation. Thus, the CB2/ß-catenin pathway appears to create a reciprocal activation feedback loop that plays a central role in the pathogenesis of kidney fibrosis.