RESUMEN

Autoimmune related kidney diseases (ARKDs), including minimal change nephropathy (MCN), membranous nephropathy (MN), IgA nephropathy (IgAN), and lupus nephritis (LN), significantly affect renal function. These diseases are characterized by the formation of local immune complexes and the subsequent activation of the complement system, leading to kidney damage and proteinuria. Despite the known patterns of glomerular injury, the specific molecular mechanisms that contribute to renal tubular damage across ARKDs remain underexplored. Laser capture microdissection and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to conduct a comparative proteomic analysis of renal tubular tissues from formalin-fixed paraffin-embedded samples. The cohort comprised of 10 normal controls (NC), 5 MCN, 4 MN, 17 IgAN, and 21 LN patients. Clinical parameters and histopathological assessments were integrated with proteomic findings to comprehensively investigate underlying pathogenic processes. Clinical evaluation indicated significant glomerular damage, as reflected by elevated urinary protein levels and reduced plasma albumin levels in patients with ARKD. Histological analyses confirmed varying degrees of tubular damage and deposition of immune complexes. Proteomic analyses identified significant changes in protein expression, particularly in complement components (C3, C4A, C4B, C8G, CFB, and SERPINA1) and mitochondrial proteins (ATP5F1E and ATP5PD), highlighting the common alterations in the complement system and mitochondrial proteins across ARKDs. These alterations suggest a novel complement-mitochondrial-epithelial-mesenchymal transition (EMT) pathway axis that contributes to tubular damage in ARKDs. Notably, significant alterations in CFB in tubular ARKD patients were revealed, implicating it as a therapeutic target. This study underscores the importance of complement activation and mitochondrial dysfunction in the pathogenesis of ARKDs, and proposes CFB as a potential therapeutic target to inhibit complement activation and mitigate tubular damage. Future research should validate the complement-mitochondrial-EMT pathway axis and explore the effects and mechanisms of CFB inhibitors in alleviating ARKD progression.

Asunto(s)

Activación de Complemento , Mitocondrias , Proteómica , Humanos , Proteómica/métodos , Femenino , Masculino , Adulto , Mitocondrias/metabolismo , Persona de Mediana Edad , Enfermedades Renales/metabolismo , Enfermedades Renales/patología , Enfermedades Renales/inmunología , Enfermedades Autoinmunes/metabolismo , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/patología , Túbulos Renales/metabolismo , Túbulos Renales/patología , Espectrometría de Masas en Tándem , Captura por Microdisección con Láser , Proteínas del Sistema Complemento/metabolismo , Cromatografía Liquida

RESUMEN

TGFß1 is a powerful regulator of fibrosis; secreted in a latent form, it becomes active after release from the latent complex. During tissue fibrosis, the EDA + isoform of cellular fibronectin is overexpressed. In pulmonary fibrosis it has been proposed that the fibronectin splice variant including an EDA domain (FN EDA+) activates latent TGFß. Our work investigates the potential of blocking the 'splicing in' of EDA with antisense oligonucleotides to inhibit TGFß1-induced EDA + fibronectin and to prevent the cascade of events initiated by TGFß1 in human renal proximal tubule cells (PTEC). Human primary PTEC were treated with TGFß1 for 48 h, medium removed and the cells transfected with RNase H-independent antisense oligonucleotides (ASO) designed to block EDA exon inclusion (ASO5). The efficacy of ASO to block EDA exon inclusion was assessed by EDA + fibronectin RNA and protein expression; the expression of TGFß, αSMA (α smooth muscle actin), MMP2 (matrix metalloproteinse-2), MMP9 (matrix metalloproteinse-9), Collagen I, K Cadherin and connexin 43 was analysed. Targeting antisense oligonucleotides designed to block EDA exon inclusion in fibronectin pre mRNA were effective in reducing the amount of TGFß1 -induced cellular EDA + fibronectin RNA and secreted EDA + fibronectin protein (assessed by western immunoblotting and immunocytochemistry) in human proximal tubule cells in an in vitro cell culture model. The effect was selective for EDA + exon with no effect on EDB + fibronectin RNA and total fibronectin mRNA. Exogenous TGFß1 induced endogenous TGFß, αSMA, MMP2, MMP9 and Col I mRNA. TGFß1 treatment for 48h reduced the expression of K-Cadherin and increased the expression of connexin-43. These TGFß1-induced pro-fibrotic changes were attenuated by ASO5 treatment. 48 h after the removal of exogenous TGFß, further increases in αSMA, MMP2, MMP9 was observed; ASO5 significantly inhibited this subsequent increase. ASO5 treatment also significantly inhibited ability of the cell culture medium harvested at the end of the experiment (96h) to stimulate SMAD3 reporter cells. The role of endogenous TGFß1 was confirmed by the use of a TGFß receptor inhibitor. Our results demonstrate a critical role of FN EDA+ in a cycle of TGFß driven pro-fibrotic responses in human PTEC and blocking its production with ASO technology offers a potential therapy to interrupt this vicious circle and hence limit the progression of renal fibrosis.

Asunto(s)

Empalme Alternativo , Células Epiteliales , Fibronectinas , Fibrosis , Túbulos Renales Proximales , Oligonucleótidos Antisentido , Factor de Crecimiento Transformador beta1 , Humanos , Fibronectinas/metabolismo , Fibronectinas/genética , Túbulos Renales Proximales/metabolismo , Túbulos Renales Proximales/patología , Túbulos Renales Proximales/citología , Oligonucleótidos Antisentido/farmacología , Oligonucleótidos Antisentido/genética , Fibrosis/metabolismo , Empalme Alternativo/genética , Factor de Crecimiento Transformador beta1/metabolismo , Células Epiteliales/metabolismo , Células Epiteliales/patología , Células Epiteliales/efectos de los fármacos , Células Cultivadas , Comunicación Autocrina , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/genética

RESUMEN

Elderly patients are prone to develop hyper- or hypokalemia, since they are susceptible to drugs or diets that affect the urinary or fecal potassium (K+) excretion. In aging mouse kidneys, in addition to glomerulosclerosis, proximal tubular atrophy, and atherosclerosis in renal arterioles, there was diffuse tubulointerstitial fibrosis with a number of inflammatory leukocytes infiltrating into the cortical interstitium. Since these pathological features greatly influence renal K+ handling, slowing the progression of kidney aging would fundamentally reduce the risk of developing hyper- or hypokalemia. Immunohistochemistry demonstrated the overexpression of K+ channels (Kv1.3) in leukocytes within the cortical interstitium, which was strongly associated with "chronic inflammation" in aging kidneys and the subsequent progression of renal fibrosis. In our basic studies, antihypertensive drugs (benidipine, nifedipine, verapamil, diltiazem) and anticholesterol drugs (lovastatin, simvastatin, pravastatin) strongly suppressed the leukocyte Kv1.3 channels and thus exerted anti-inflammatory effects. Given such pharmacological properties of these drugs, they may also be useful in slowing the progression of tubulointerstitial fibrosis in aging kidneys and reducing the risk of hyper- or hypokalemia in elderly patients.

RESUMEN

Hyperuricemic nephropathy (HN) is a global metabolic disorder characterized by uric acid (UA) metabolism dysfunction, resulting in hyperuricemia (HUA) and tubulointerstitial fibrosis (TIF). Sodium-dependent glucose transporter 2 inhibitor, dapagliflozin, has shown potential in reducing serum UA levels in patients with chronic kidney disease (CKD), though its protective effects against HN remain uncertain. This study investigates the functional, pathological, and molecular changes in HN through histological, biochemical, and transcriptomic analyses in patients, HN mice, and UA-stimulated HK-2 cells. Findings indicate UA-induced tubular dysfunction and fibrotic activation, which dapagliflozin significantly mitigates. Transcriptomic analysis identifies estrogen-related receptor α (ERRα), a downregulated transcription factor in HN. ERRα knockin mice and ERRα-overexpressed HK-2 cells demonstrate UA resistance, while ERRα inhibition exacerbates UA effects. Dapagliflozin targets ERRα, activating the ERRα-organic anion transporter 1 (OAT1) axis to enhance UA excretion and reduce TIF. Furthermore, dapagliflozin ameliorates renal fibrosis in non-HN CKD models, underscoring the therapeutic significance of the ERRα-OAT1 axis in HN and CKD.

Asunto(s)

Compuestos de Bencidrilo , Fibrosis , Glucósidos , Hiperuricemia , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Animales , Glucósidos/farmacología , Glucósidos/uso terapéutico , Compuestos de Bencidrilo/farmacología , Fibrosis/tratamiento farmacológico , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología , Hiperuricemia/tratamiento farmacológico , Hiperuricemia/complicaciones , Humanos , Ratones , Masculino , Receptor Relacionado con Estrógeno ERRalfa , Enfermedades Renales/tratamiento farmacológico , Enfermedades Renales/patología , Enfermedades Renales/metabolismo , Riñón/patología , Riñón/efectos de los fármacos , Riñón/metabolismo , Ratones Endogámicos C57BL , Ácido Úrico/sangre , Receptores de Estrógenos/metabolismo , Proteína 1 de Transporte de Anión Orgánico/metabolismo , Proteína 1 de Transporte de Anión Orgánico/genética , Línea Celular , Insuficiencia Renal Crónica/tratamiento farmacológico , Insuficiencia Renal Crónica/patología , Modelos Animales de Enfermedad , Femenino

RESUMEN

Long non-coding RNA (lncRNA) H19 is an extensively studied lncRNA that is related to numerous pathological changes. Our previous findings have documented that serum lncRNA H19 levels are decreased in patients with chronic kidney disorder and lncRNA H19 reduction is closely correlated with renal tubulointerstitial fibrosis, an essential step in developing end-stage kidney disease. Nonetheless, the precise function and mechanism of lncRNA H19 in renal tubulointerstitial fibrosis are not fully comprehended. The present work utilized a mouse model of unilateral ureteral obstruction (UUO) and transforming growth factor-ß1 (TGF-ß1)-stimulated HK-2 cells to investigate the possible role and mechanism of lncRNA H19 in renal tubulointerstitial fibrosis were investigated. Levels of lncRNA H19 decreased in kidneys of mice with UUO and HK-2 cells stimulated with TGF-ß1. Up-regulation of lncRNA H19 in mouse kidneys remarkably relieved kidney injury, fibrosis and inflammation triggered by UUO. Moreover, the increase of lncRNA H19 in HK-2 cells reduced epithelial-to-mesenchymal transition (EMT) induced by TGF-ß1. Notably, up-regulation of lncRNA H19 reduced lipid accumulation and triacylglycerol content in kidneys of mice with UUO and TGF-ß1-stimulated HK-2 cells, accompanied by the up-regulation of long-chain acyl-CoA synthetase 1 (ACSL1). lncRNA H19 was identified as a sponge of microRNA-130a-3p, through which lncRNA H19 modulates the expression of ACSL1. The overexpression of microRNA-130a-3p reversed the lncRNA H19-induced increases in the expression of ACSL1. The suppressive effects of lncRNA H19 overexpression on the EMT, inflammation and lipid accumulation in HK-2 cells were diminished by ACSL1 silencing or microRNA-130a-3p overexpression. Overall, the findings showed that lncRNA H19 ameliorated renal tubulointerstitial fibrosis by reducing lipid deposition via modulation of the microRNA-130a-3p/ACSL1 axis.

RESUMEN

Tubulointerstitial fibrosis (TIF) is one of the key indicators in evaluating the renal function of patients. Mild TIF can cause a vicious cycle of renal tubular glomerular injury and aggravate renal disease. Therefore, studying the mechanisms underlying TIF is essential to identify therapeutic targets, thereby protecting the renal function of patients with timely intervention. Astragaloside IV (AS-IV) is a Chinese medicine component that has been shown to inhibit the occurrence and progression of TIF via multiple pathways. Previous studies have reported that AS-IV protected against TIF by inhibiting inflammation, autophagy, endoplasmic reticulum stress, macrophages, and transforming growth factor-ß1, which laid the foundation for the development of a new preventive and therapeutic option for TIF.

RESUMEN

BACKGROUND AND PURPOSE: Activation of the renin-angiotensin system, as a hallmark of hypertension and chronic kidney diseases (CKD) is the key pathophysiological factor contributing to the progression of tubulointerstitial fibrosis. LIM and senescent cell antigen-like domains protein 1 (LIMS1) plays an essential role in controlling of cell behaviour through the formation of complexes with other proteins. Here, the function and regulation of LIMS1 in angiotensin II (Ang II)-induced hypertension and tubulointerstitial fibrosis was investigated. EXPERIMENTAL APPROACH: C57BL/6 mice were treated with Ang II to induce tubulointerstitial fibrosis. Hypoxia-inducible factor-1α (HIF-1α) renal tubular-specific knockout mice or LIMS1 knockdown AAV was used to investigate their effects on Ang II-induced renal interstitial fibrosis. In vitro, HIF-1α or LIMS1 was knocked down or overexpressed in HK2 cells after exposure to Ang II. KEY RESULTS: Increased expression of tubular LIMS1 was observed in human kidney with hypertensive nephropathy and in murine kidney from Ang II-induced hypertension model. Tubular-specific knockdown of LIMS1 ameliorated Ang II-induced tubulointerstitial fibrosis in mice. Furthermore, we demonstrated that LIMS1 was transcriptionally regulated by HIF-1α in tubular cells and that tubular HIF-1α knockout ameliorates LIMS1-mediated tubulointerstitial fibrosis. In addition, LIMS1 promotes Ang II-induced tubulointerstitial fibrosis by interacting with vimentin. CONCLUSION AND IMPLICATIONS: We conclude that HIF-1α transcriptionally regulated LIMS1 plays a central role in Ang II-induced tubulointerstitial fibrosis through interacting with vimentin. Our finding represents a new insight into the mechanism of Ang II-induced tubulointerstitial fibrosis and provides a novel therapeutic target for progression of CKD.

Asunto(s)

Angiotensina II , Fibrosis , Hipertensión , Subunidad alfa del Factor 1 Inducible por Hipoxia , Ratones Endogámicos C57BL , Vimentina , Animales , Angiotensina II/toxicidad , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Fibrosis/inducido químicamente , Ratones , Humanos , Vimentina/metabolismo , Masculino , Hipertensión/inducido químicamente , Hipertensión/metabolismo , Hipertensión/patología , Ratones Noqueados , Proteínas con Dominio LIM/metabolismo , Proteínas con Dominio LIM/genética

RESUMEN

Metabolic acidosis is a frequent complication of chronic kidney disease and is associated with a number of adverse outcomes, including worsening kidney function, poor musculoskeletal health, cardiovascular events, and death. Mechanisms that prevent metabolic acidosis detrimentally promote further kidney damage, creating a cycle between acid accumulation and acid-mediated kidney injury. Disrupting this cycle through the provision of alkali, most commonly using sodium bicarbonate, is hypothesized to preserve kidney function while also mitigating adverse effects of excess acid on bone and muscle. However, results from clinical trials have been conflicting. There is also significant interest to determine whether sodium bicarbonate might improve patient outcomes for those who do not have overt metabolic acidosis. Such individuals are hypothesized to be experiencing acid-mediated organ damage despite having a normal serum bicarbonate concentration, a state often referred to as subclinical metabolic acidosis. Results from small- to medium-sized trials in individuals with subclinical metabolic acidosis have also been inconclusive. Well-powered clinical trials to determine the efficacy and safety of sodium bicarbonate are necessary to determine if this intervention improves patient outcomes.

Asunto(s)

Acidosis , Insuficiencia Renal Crónica , Bicarbonato de Sodio , Humanos , Acidosis/etiología , Acidosis/tratamiento farmacológico , Acidosis/metabolismo , Insuficiencia Renal Crónica/tratamiento farmacológico , Insuficiencia Renal Crónica/metabolismo , Insuficiencia Renal Crónica/complicaciones , Bicarbonato de Sodio/uso terapéutico , Animales , Resultado del Tratamiento

RESUMEN

Anti-partial epithelial-mesenchymal transition (pEMT) treatment of renal tubular epithelial cells (TECs) represents a promising therapeutic approach. Hyperuricemia nephropathy (HN) arises as a consequence of hyperuricemia (HUA)-induced tubulointerstitial fibrosis (TIF). Studies have suggested that the Ras homolog member A (RhoA)/Rho-associated kinase (ROCK) pathway is a crucial signaling transduction system in renal fibrosis. Fasudil, a RhoA/ROCK inhibitor, has exhibited the potential to prevent fibrosis progress. However, its impact on the pEMT of TECs in HN remains unclear. Here, an HN rat model and an uric acid (UA)-stimulated human kidney 2 (HK2) cell model were established and treated with Fasudil to explore its effects. Furthermore, the underlying mechanism of action involved in the attenuation of pEMT in TECs by Fasudil during HN was probed by using multiple molecular approaches. The HN rat model exhibited significant renal dysfunction and histopathological damage, whereas in vitro and in vivo experiments further confirmed the pEMT status accompanied by RhoA/ROCK pathway activation and oxidative stress in tubular cells exposed to UA. Notably, Fasudil ameliorated these pathological changes, and this was consistent with the trend of ROCK silencing in vitro. Mechanistically, we identified the Neh2 domain of nuclear factor erythroid 2-related factor 2 (Nrf2) as a target of Fasudil for the first time. Fasudil targets Nrf2 activation and antagonizes oxidative stress to attenuate the pEMT of TECs in HN. Our findings suggest that Fasudil attenuates oxidative stress-induced pEMT of TECs in HN by targeting Nrf2 activation. Thus, Fasudil is a potential therapeutic agent for the treatment of HN.

Asunto(s)

1-(5-Isoquinolinesulfonil)-2-Metilpiperazina , Células Epiteliales , Transición Epitelial-Mesenquimal , Hiperuricemia , Enfermedades Renales , Túbulos Renales , Factor 2 Relacionado con NF-E2 , Estrés Oxidativo , Factor 2 Relacionado con NF-E2/metabolismo , Animales , Transición Epitelial-Mesenquimal/efectos de los fármacos , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/análogos & derivados , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/farmacología , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/uso terapéutico , Estrés Oxidativo/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Células Epiteliales/patología , Hiperuricemia/tratamiento farmacológico , Hiperuricemia/metabolismo , Humanos , Ratas , Masculino , Túbulos Renales/efectos de los fármacos , Túbulos Renales/patología , Túbulos Renales/metabolismo , Línea Celular , Enfermedades Renales/tratamiento farmacológico , Enfermedades Renales/patología , Enfermedades Renales/metabolismo , Quinasas Asociadas a rho/metabolismo , Quinasas Asociadas a rho/antagonistas & inhibidores , Ratas Sprague-Dawley , Modelos Animales de Enfermedad , Transducción de Señal/efectos de los fármacos

RESUMEN

Tubulointerstitial fibrosis is an inevitable consequence of all progressive chronic kidney disease (CKD) and contributes to a substantial health burden worldwide. Icariin, an active flavonoid glycoside obtained from Epimedium species, exerts potential antifibrotic effect. The study aimed to explore the protective effects of icariin against tubulointerstitial fibrosis in unilateral ureteral obstruction (UUO)-induced CKD mice and TGF-ß1-treated HK-2 cells, and furthermore, to elucidate the underlying mechanisms. The results demonstrated that icariin significantly improved renal function, alleviated tubular injuries, and reduced fibrotic lesions in UUO mice. Furthermore, icariin suppressed renal inflammation, reduced oxidative stress as evidenced by elevated superoxide dismutase activity and decreased malondialdehyde level. Additionally, TOMM20 immunofluorescence staining and transmission electron microscope revealed that mitochondrial mass and morphology of tubular epithelial cells in UUO mice was restored by icariin. In HK-2 cells treated with TGF-ß1, icariin markedly decreased profibrotic proteins expression, inhibited inflammatory factors, and protected mitochondria along with preserving mitochondrial morphology, reducing reactive oxygen species (ROS) and mitochondrial ROS (mtROS) overproduction, and preserving membrane potential. Further investigations demonstrated that icariin could activate nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway both in vivo and in vitro, whereas inhibition of Nrf2 by ML385 counteracted the protective effects of icariin on TGF-ß1-induced HK-2 cells. In conclusion, icariin protects against renal inflammation and tubulointerstitial fibrosis at least partly through Nrf2-mediated attenuation of mitochondrial dysfunction, which suggests that icariin could be developed as a promising therapeutic candidate for the treatment of CKD.

Asunto(s)

Insuficiencia Renal Crónica , Obstrucción Ureteral , Ratones , Animales , Riñón/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Flavonoides/farmacología , Obstrucción Ureteral/metabolismo , Obstrucción Ureteral/patología , Insuficiencia Renal Crónica/tratamiento farmacológico , Fibrosis , Inflamación/metabolismo

RESUMEN

Renal tubulointerstitial fibrosis (RTIF) is a common feature and inevitable consequence of all progressive chronic kidney diseases, leading to end-stage renal failure regardless of the initial cause. Although research over the past few decades has greatly improved our understanding of the pathophysiology of RTIF, until now there has been no specific treatment available that can halt the progression of RTIF. Norcantharidin (NCTD) is a demethylated analogue of cantharidin, a natural compound isolated from 1500 species of medicinal insect, the blister beetle (Mylabris phalerata Pallas), traditionally used for medicinal purposes. Many studies have found that NCTD can attenuate RTIF and has the potential to be an anti-RTIF drug. This article reviews the recent progress of NCTD in the treatment of RTIF, with emphasis on the pharmacological mechanism of NCTD against RTIF.

Asunto(s)

Enfermedades Renales , Humanos , Enfermedades Renales/tratamiento farmacológico , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Fibrosis

RESUMEN

BACKGROUND: Tubulointerstitial fibrosis plays an important role in the progression of diabetic kidney disease (DKD). Sacubitril/valsartan (Sac/Val) exerts a robust beneficial effect in DKD. However, the potential functional effect of Sac/Val on tubulointerstitial fibrosis in DKD is still largely unclear. METHODS: Streptozotocin-induced diabetic mice were given Sac/Val or Val by intragastric administration once a day for 12 weeks. The renal function, the pathological changes of tubule injury and tubulointerstitial fibrosis, as well as mitochondrial morphology of renal tubules in mice, were evaluated. Genome-wide gene expression analysis was performed to identify the potential mechanisms. Meanwhile, human tubular epithelial cells (HK-2) were cultured in high glucose condition containing LBQ657/valsartan (LBQ/Val). Further, mitochondrial functions and Sirt1/PGC1α pathway of tubular epithelial cells were assessed by Western blot, Real-time-PCR, JC-1, MitoSOX or MitoTracker. Finally, the Sirt1 specific inhibitor, EX527, was used to explore the potential effects of Sirt1 signaling in vivo and in vitro. RESULTS: We found that Sac/Val significantly ameliorated the decline of renal function and tubulointerstitial fibrosis in DKD mice. The enrichment analysis of gene expression indicated metabolism as an important modulator in DKD mice with Sac/Val administration, in which mitochondrial homeostasis plays a pivotal role. Then, the decreased expression of Tfam and Cox IV;, as well as changes of mitochondrial function and morphology, demonstrated the disruption of mitochondrial homeostasis under DKD conditions. Interestingly, Sac/Val administration was found to restore mitochondrial homeostasis in DKD mice and in vitro model of HK-2 cells. Further, we demonstrated that Sirt1/PGC1α, a crucial pathway in mitochondrial homeostasis, was activated by Sac/Val both in vivo and in vitro. Finally, the beneficial effects of Sac/Val on mitochondrial homeostasis and tubulointerstitial fibrosis was partially abolished in the presence of Sirt1 specific inhibitor. CONCLUSIONS: Taken together, we demonstrate that Sac/Val ameliorates tubulointerstitial fibrosis by restoring Sirt1/PGC1α pathway-mediated mitochondrial homeostasis in DKD, providing a theoretical basis for delaying the progression of DKD in clinical practice.

RESUMEN

BACKGROUND: Development of end-stage renal disease is predominantly attributed to diabetic nephropathy (DN). Previous studies have indicated that myricetin possesses the potential to mitigate the pathological alterations observed in renal tissue. Nevertheless, the precise molecular mechanism through which myricetin influences the progression of DN remains uncertain. AIM: To investigate the effects of myricetin on DN and explore its potential therapeutic mechanism. METHODS: Db/db mice were administered myricetin intragastrically on a daily basis at doses of 50 mg/kg or 100 mg/kg for a duration of 12 wk. Subsequently, blood and urine indexes were assessed, along with examination of renal tissue pathology. Kidney morphology and fibrosis were evaluated using various staining techniques including hematoxylin and eosin, periodic acid-Schiff, Masson's trichrome, and Sirius-red. Additionally, high-glucose culturing was conducted on the RAW 264.7 cell line, treated with 25 mM myricetin or co-administered with the PI3K/Akt inhibitor LY294002 for a period of 24 h. In both in vivo and in vitro settings, quantification of inflammation factor levels was conducted using western blotting, real-time qPCR and ELISA. RESULTS: In db/db mice, administration of myricetin led to a mitigating effect on DN-induced renal dysfunction and fibrosis. Notably, we observed a significant reduction in expressions of the kidney injury markers kidney injury molecule-1 and neutrophil gelatinase associated lipocalin, along with a decrease in expressions of inflammatory cytokine-related factors. Furthermore, myricetin treatment effectively inhibited the up-regulation of tumor necrosis factor-alpha, interleukin-6, and interluekin-1ß induced by high glucose in RAW 264.7 cells. Additionally, myricetin modulated the M1-type polarization of the RAW 264.7 cells. Molecular docking and bioinformatic analyses revealed Akt as the target of myricetin. The protective effect of myricetin was nullified upon blocking the polarization of RAW 264.7 via inhibition of PI3K/Akt activation using LY294002. CONCLUSION: This study demonstrated that myricetin effectively mitigates kidney injury in DN mice through the regulation of macrophage polarization via the PI3K/Akt signaling pathway.

RESUMEN

Senescence of kidney tubules leads to tubulointerstitial fibrosis (TIF). Proximal tubular epithelial cells undergo stress-induced senescence during diabetes and episodes of acute kidney injury (AKI), and combining these injuries promotes the progression of diabetic kidney disease (DKD). Since TIF is crucial to progression of DKD, we examined the therapeutic potential of targeting senescence with a senolytic drug (HSP90 inhibitor) and/or a senostatic drug (ASK1 inhibitor) in a model of TIF in which AKI is superimposed on diabetes. After 8 weeks of streptozotocin-induced diabetes, mice underwent bilateral clamping of renal pedicles to induce mild AKI, followed by 28 days of reperfusion. Groups of mice (n=10-12) received either vehicle, HSP90 inhibitor (alvespimycin), ASK1 inhibitor (GS-444217), or both treatments. Vehicle-treated mice displayed tubular injury at day 3 and extensive tubular cell senescence at day 10, which remained unresolved at day 28. Markers of senescence (Cdkn1a and Cdkn2a), inflammation (Cd68, Tnf, and Ccl2), and TIF (Col1a1, Col4a3, α-Sma/Acta2, and Tgfb1) were elevated at day 28, coinciding with renal function impairment. Treatment with alvespimycin alone reduced kidney senescence and levels of Col1a1, Acta2, Tgfb1, and Cd68; however, further treatment with GS-444217 also reduced Col4a3, Tnf, Ccl2, and renal function impairment. Senolytic therapy can inhibit TIF during DKD, but its effectiveness can be improved by follow-up treatment with a senostatic inhibitor, which has important implications for treating progressive DKD.

Asunto(s)

Lesión Renal Aguda , Benzoquinonas , Diabetes Mellitus Experimental , Nefropatías Diabéticas , Imidazoles , Lactamas Macrocíclicas , Piridinas , Ratones , Animales , Senoterapéuticos , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/patología , Riñón/patología , Lesión Renal Aguda/tratamiento farmacológico , Lesión Renal Aguda/etiología , Lesión Renal Aguda/patología , Nefropatías Diabéticas/tratamiento farmacológico , Nefropatías Diabéticas/patología , Fibrosis , Senescencia Celular

RESUMEN

Our previous study found that miR-26a alleviates aldosterone-induced tubulointerstitial fibrosis (TIF). However, the effect of miR-26a on TIF in diabetic kidney disease (DKD) remains unclear. This study clarifies the role and possible mechanism of exogenous miR-26a in controlling the progression of TIF in DKD models. Firstly, we showed that miR-26a was markedly decreased in type 2 diabetic db/db mice and mouse tubular epithelial cells (mTECs) treated with high glucose (HG, 30 mM) using RT-qPCR. We then used adeno-associated virus carrying miR-26a and adenovirus miR-26a to enhance the expression of miR-26a in vivo and in vitro. Overexpressing miR-26a alleviated the TIF in db/db mice and the extracellular matrix (ECM) deposition in HG-stimulated mTECs. These protective effects were caused by reducing expression of protease-activated receptor 4 (PAR4), which involved in multiple pro-fibrotic pathways. The rescue of PAR4 expression reversed the anti-fibrosis activity of miR-26a. We conclude that miR-26a alleviates TIF in DKD models by directly targeting PAR4, which may provide a novel molecular strategy for DKD therapy.

Asunto(s)

Diabetes Mellitus , Nefropatías Diabéticas , MicroARNs , Animales , Ratones , Nefropatías Diabéticas/metabolismo , Fibrosis , MicroARNs/metabolismo , Receptores de Trombina

RESUMEN

Proteinuria is a well-established biomarker of chronic kidney disease (CKD) and a risk predictor of associated disease outcomes. Proteinuria is also a driver of CKD progression toward end-stage kidney disease. Toxic effects of filtered proteins on proximal tubular epithelial cells enhance tubular atrophy and interstitial fibrosis. The extent of protein toxicity and the underlying molecular mechanisms responsible for tubular injury during proteinuria remain unclear. Nevertheless, albumin elicits its toxic effects when degraded and reabsorbed by proximal tubular epithelial cells. Overall, healthy kidneys excrete over 1000 individual proteins, which may be potentially harmful to proximal tubular epithelial cells when filtered and/or reabsorbed in excess. Proteinuria can cause kidney damage, inflammation and fibrosis by increasing reactive oxygen species, autophagy dysfunction, lysosomal membrane permeabilization, endoplasmic reticulum stress and complement activation. Here we summarize toxic proteins reported in proteinuria and the current understanding of molecular mechanisms of toxicity of proteins on proximal tubular epithelial cells leading to CKD progression.

Asunto(s)

Fallo Renal Crónico , Insuficiencia Renal Crónica , Humanos , Proteinuria/complicaciones , Riñón , Insuficiencia Renal Crónica/complicaciones , Fallo Renal Crónico/complicaciones , Fibrosis , Progresión de la Enfermedad

RESUMEN

BACKGROUND:Autophagy and ferroptosis play important roles in the development of chronic kidney disease,but the molecular mechanisms and gene targets related to autophagy and ferroptosis in renal tissue of chronic kidney disease are still unclear. OBJECTIVE:To screen differentially expressed genes in chronic kidney disease-related datasets based on bioinformatics,and to explore potential key biomarkers suitable for screening renal function progression in patients with chronic kidney disease. METHODS:(1)The GSE137570 dataset was obtained from GEO database to screen the differentially expressed genes by Networkanalyst database analysis.Ferroptosis and autophagy related targets were obtained by OMIM,GENECARD,FerrDb and HAMdb databases.The respective data were intersected to obtain autophagy-ferroptosis related differentially expressed genes in chronic kidney disease for parallel enrichment analysis.The STRING website was used to construct the protein-protein interaction network of differentially expressed genes,which was imported into Cytoscape software and analyzed by MCODE and Cytohubba plug-in to screen potential core targets.Enrichment analysis was performed to obtain the functions of these potential core targets.(2)In the in vitro experiment,mouse renal tubular epithelial cells were divided into two groups:the control group received no intervention,while the model group was stimulated with 5 ng/mL transforming growth factor β1 for 24 hours to induce mesenchymal transformation of renal tubular epithelial cells.Flow cytometry was used to measure the levels of reactive oxygen species and changes in mitochondrial membrane potential in the cells.RT-PCR was employed to assess ferroptosis,autophagy-related markers,and the mRNA expression of potential core targets in the cells. RESULTS AND CONCLUSION:After screening the GSE137570 dataset,a total of 480 differentially expressed genes were obtained,including 104 upregulated genes and 376 downregulated genes(log2|(FC)|>1,P<0.05).There were 562 ferroptosis-related targets and 1 266 autophagy-related targets obtained from the OMIM,GENECARD,FerrDb,and HAMdb databases.Intersection of differentially expressed genes with ferroptosis-and autophagy-related targets yielded 15 ferroptosis-related targets and 18 autophagy-related targets,respectively.The enrichment analysis results indicate that ferroptosis-related differentially expressed genes are primarily involved in biological processes such as sulfur amino acid metabolism,neutrophil degranulation,and ferroptosis signaling pathways.Autophagy-related differentially expressed genes are mainly enriched in biological processes such as platelet degranulation,extracellular matrix degradation,and receptor tyrosine kinase signaling.After screened by MCODE and CytoHubba,key genes were identified in the protein-protein interaction network,including CD44,ALB,TIMP1,PLG,CCL2,and DPP4.Immune infiltration analysis results indicate that immune cells such as B cells,CD4+ T cells,NK cells,and monocytes show significant differential expression in renal tissue after chronic kidney disease,and the core targets are also significantly correlated with these immune cells(P<0.05).The results of receiver operator characteristic curve analysis further demonstrate that the pathological progression of chronic kidney disease can be effectively diagnosed by CD44,ALB,TIMP1,PLG,CCL2,and DPP4.Single-cell sequencing results show that,except for PLG,the expression of target genes in the renal tissue of mice in each model group is generally consistent with the results of this experiment.RT-PCR results demonstrate that,for the validation of autophagy and ferroptosis phenotypes,compared with the control group,the model group shows a significant decrease in mRNA expression of LC3B,Nrf2,and SLC7A11(P<0.05),and a significant increase in P62 mRNA expression(P<0.05).Regarding the validation of potential core targets,compared with the control group,the model group exhibits a significant decrease in mRNA expression of ALB and PLG(P<0.05),and a significant increase in TIMP1 and CCL2 mRNA expression(P<0.05).Overall,these findings indicate that,through bioinformatics analysis and experimental validation,CD44,ALB,TIMP1,PLG,and CCL2 are abnormally expressed in the renal tissue of patients with chronic kidney disease,closely correlated with estimated glomerular filtration rate and tubulointerstitial fibrosis,and maybe play a predictive role in the progression of chronic kidney disease.

RESUMEN

Renal fibrosis, especially tubulointerstitial fibrosis, is the most common pathway of all chronic kidney diseases progressing to end-stage renal diseases. Several adaptive reactions occur in renal tubular epithelial cells after chronic injury, such as changes in glycolipid metabolism, unfolded protein response, autophagy and senescence, epithelial-to-mesenchymal transition and G2/M cell cycle arrest. Maladaptive repair mechanisms can induce tubulointerstitial fibrosis. This article will discuss the molecular mechanism of these adaptive responses of renal tubular epithelial cells driving renal tubulointerstitial fibrosis, and provide a basis for exploring new drug targets for renal tubulointerstitial fibrosis.

RESUMEN

Glomerulosclerosis and tubulointerstitial fibrosis (TIF) are closely involved in the development of diabetic nephropathy (DN). Moreover, the development of TIF is closely related to epithelial-to-mesenchymal transition (EMT). Tanshinone IIA (Tan) has various pharmacological effects, especially the anti-fibrotic effect. And it is mainly used in the clinical treatment of cardiovascular diseases. Currently, the protective effect of Tan on DN and its possible mechanism have not been clearly elucidated. Our previous studies illustrated that Tan could improve the EMT of HK-2 cells induced by high glucose by regulating the vitamin D receptor (VDR)/Wnt/ß-catenin pathway. Here, we collected demographic information and laboratory results from the National Health and Nutrition Examination Survey (NHANES) database in order to investigate the relationship between VD and DN. Then, we established a DN model and treated DN rats with Tan and paricalcitol (Par) for 6 weeks. We subsequently compared the changes in general condition, renal function, pathological changes, and TIF-related protein expression levels of control rats, DN rats induced by STZ, DN rats with Tan at 5.4 mg/kg, DN rats with Tan at 10.8 mg/kg, and DN rats with Par at 0.054 µg/kg, to explore the effect and mechanism of Tan and Par on DN rats. The results showed that VD had a protective effect against DN in diabetic patients. And we found that Tan had a protective effect on renal fibrosis in DN rats, which was superior to Par in improving the symptoms of "three more and one less," reducing fasting blood glucose level, improving renal index, BUN/SCr, and UACR, reducing histopathological damage of kidney, and improving the expression of fibrosis-related proteins in kidney tissue by regulating VDR/Wnt/ß-catenin pathway. Tan was superior to Par in ameliorating tubulointerstitial fibrosis by regulating VDR/Wnt/ß-catenin pathway in rats with diabetic nephropathy.

RESUMEN

Tubulointerstitial fibrosis (TIF) plays a crucial role in the progression of diabetic kidney disease (DKD). However, the underlying molecular mechanisms remain obscure. The present study aimed to examine whether transmembrane member 16A (TMEM16A), a Ca2+-activated chloride channel, contributes to the development of TIF in DKD. Interestingly, we found that TMEM16A expression was significantly up-regulated in tubule of murine model of DKD, which was associated with development of TIF. In vivo inhibition of TMEM16A channel activity with specific inhibitors Ani9 effectively protects against TIF. Then, we found that TMEM16A activation induces tubular mitochondrial dysfunction in in vivo and in vitro models, with the evidence of the TMEM16A inhibition with specific inhibitor. Mechanically, TMEM16A mediated tubular mitochondrial dysfunction through inhibiting PGC-1α, whereas overexpression of PGC-1α could rescue the changes. In addition, TMEM16A-induced fibrogenesis was dependent on increased intracellular Cl-, and reducing intracellular Cl- significantly blunted high glucose-induced PGC-1α and profibrotic factors expression. Taken together, our studies demonstrated that tubular TMEM16A promotes TIF by suppressing PGC-1α-mediated mitochondrial homeostasis in DKD. Blockade of TMEM16A may serve as a novel therapeutic approach to ameliorate TIF.

Asunto(s)

Diabetes Mellitus , Nefropatías Diabéticas , Animales , Ratones , Nefropatías Diabéticas/genética , Homeostasis , Mitocondrias , Fibrosis