HK-2 Cells Research Articles

M1 Macrophage-Derived Exosomal MiR-155 Enhances Autophagy in Sepsis-Triggered Acute Kidney Injury

Sepsis-induced Acute kidney injury (SA-AKI), a common complication in sepsis, significantly impacts patients’ health and quality of life. M1 macrophages have been demonstrated to release inflammatory mediators that exacerbate kidney injury. MiR-155 has been implicated in promoting inflammation and damage during sepsis while reducing miR-155 levels alleviates SA-AKI. However, the relationship between miR-155 and M1 macrophage-derived exosomes in regulating autophagy during SA-AKI remains unclear. In this study, we aim to investigate the relationship between M1 macrophage-derived exosomes and miR-155 in regulating autophagy during SA-AKI. A mouse model of SA-AKI was established by performing cecal ligation and puncture (CLP) surgery. Additionally, the HK-2 cell line was utilized to establish a sepsis cell model by inducing lipopolysaccharide (LPS). We demonstrated that the mice model of SA-AKI exhibited renal injury along with enhanced autophagy, inflammation response, and macrophage polarization after CLP surgery. M1 macrophages attenuated cell viability and enhanced autophagy in LPS-treated HK-2 cells. Additionally, M1 macrophage-derived exosomes were observed to enhance autophagy in LPS-treated HK-2 cells. Furthermore, we confirmed an increased expression of miR-155 in M1 macrophage-derived exosomes. Furthermore, exosome-mediated miR-155 enhanced autophagy in LPS-treated HK-2 cells. In conclusion, this study provides the first evidence that exosomal miR-155 derived from M1 macrophages enhances autophagy in SA-AKI. These findings suggest that targeting exosomal miR-155 could be a promising therapeutic strategy for SA-AKI.

Vaccarin suppresses diabetic nephropathy through inhibiting the EGFR/ERK1/2 signaling pathway.

Diabetic nephropathy (DN) is recognized as one of the primary causes of chronic kidney disease and end-stage renal disease. Vaccarin (VAC) confers favorable effects on cardiovascular and metabolic diseases, including type 2 diabetes mellitus (T2DM). Nonetheless, the potential role and mechanism of VAC in the etiology of DN have yet to be completely elucidated. In this study, a classical mouse model of T2DM is experimentally induced via a high-fat diet (HFD)/streptozocin (STZ) regimen. Renal histological changes are assessed via H&E staining. Masson staining and immunohistochemistry (IHC) are employed to assess renal fibrosis. RT-PCR is utilized to quantify the mRNA levels of renal fibrosis, oxidative stress and inflammation markers. The levels of malondialdehyde (MDA) and reactive oxygen species (ROS), as well as the content of glutathione peroxidase (GSH-Px), are measured. The protein expressions of collagen I, TGF-β1, α-SMA, E-cadherin, Nrf2, catalase, SOD3, SOD2, SOD1, p-ERK, p-EGFR (Y845), p-EGFR (Y1173), p-NFκB P65, t-ERK, t-EGFR and t-NFκB P65 are detected by western blot analysis. Our results reveal that VAC has a beneficial effect on DN mice by improving renal function and mitigating histological damage. This is achieved through its inhibition of renal fibrosis, inflammatory cytokine overproduction, and ROS generation. Moreover, VAC treatment effectively suppresses the process of epithelial-mesenchymal transition (EMT), a crucial characteristic of renal fibrosis, in high glucose (HG)-induced HK-2 cells. Network pharmacology analysis and molecular docking identify epidermal growth factor receptor (EGFR) as a potential target for VAC. Amino acid site mutations reveal that Lys-879, Ile-918, and Ala-920 of EGFR may mediate the direct binding of VAC to EGFR. In support of these findings, VAC reduces the phosphorylation levels of both EGFR and its downstream mediator, extracellular signal-regulated kinase 1/2 (ERK1/2), in diabetic kidneys and HG-treated HK-2 cells. Notably, blocking either EGFR or ERK1/2 yields renal benefits similar to those observed with VAC treatment. Therefore, this study reveals that VAC attenuates renal damage via inactivation of the EGFR/ERK1/2 signaling axis in T2DM patients.

Exploring Novel Genome Instability-associated lncRNAs and their Potential Function in Pan-Renal Cell Carcinoma.

Genomic instability can drive clonal evolution, continuous modification of tumor genomes, and tumor genomic heterogeneity. The molecular mechanism of genomic instability still needs further investigation. This study aims to identify novel genome instabilityassociated lncRNAs (GI-lncRNAs) and investigate the role of genome instability in pan-Renal cell carcinoma (RCC). A mutator hypothesis was employed, combining the TCGA database of somatic mutation (SM) information, to identify GI-lncRNAs. Subsequently, a training cohort (n = 442) and a testing cohort (n = 439) were formed by randomly dividing all RCC patients. Based on the training cohort dataset, a multivariate Cox regression analysis lncRNAs risk model was created. Further validations were performed in the testing cohort, TCGA cohort, and different RCC subtypes. To confirm the relative expression levels of lncRNAs in HK-2, 786-O, and 769-P cells, qPCR was carried out. Functional pathway enrichment analyses were performed for further investigation. A total of 170 novel GI-lncRNAs were identified. The lncRNA prognostic risk model was constructed based on LINC00460, AC073218.1, AC010789.1, and COLCA1. This risk model successfully differentiated patients into distinct risk groups with significantly different clinical outcomes. The model was further validated in multiple independent patient cohorts. Additionally, functional and pathway enrichment analyses revealed that GI-lncRNAs play a crucial role in GI. Furthermore, the assessments of immune response, drug sensitivity, and cancer stemness revealed a significant relationship between GI-lncRNAs and tumor microenvironment infiltration, mutational burden, microsatellite instability, and drug resistance. In this study, we discovered four novel GI-lncRNAs and developed a novel signature that effectively predicted clinical outcomes in pan-RCC. The findings provide valuable insights for pan-RCC immunotherapy and shed light on potential underlying mechanisms.

TRPC6-Calpain-1 Axis Promotes Tubulointerstitial Inflammation by Inhibiting Mitophagy in Diabetic Kidney Disease

IntroductionRenal tubulointerstitial inflammation represents an effective indicator for predicting the progression of diabetic kidney disease (DKD). Mitophagy abnormality is one of the most important factors involving in tubule injury. However, the exact molecular mechanism underlying mitophagy abnormality-mediated tubulointerstitial inflammation in DKD remains poorly understood. MethodsHere, Streptozotocin-induced DKD mouse model was established and HK-2 cells treated with high-glucose (HG) served as an in vitro model. The tubular mitophagy was regulated through pharmacological Urolithin A administration. The functional effect of TRPC6 was explored using genetic interventions in vivo and in vitro. ResultsWe found that renal tubulointerstitial inflammation in DKD was closely associated with mitophagy inhibition, which was mediated by disturbance of PINK1/Parkin pathway. Mitophagy activation significantly attenuated tubular injury and tubulointerstitial inflammation. Further, it was found that TRPC6 was markedly increased in DKD and played an essential role in mitophagy inhibition through activating Calpain1. Knockdown of TRPC6 partially reversed mitophagy abnormality and consequently attenuated tubular injury and tubulointerstitial inflammation in vivo and in vitro. Finally, we found that tubular TRPC6-mediated mitophagy inhibition was blocked with BAPTA (a specific Ca2+ chelator) or Calpeptin (a specific Calpain1 inhibitor). ConclusionsOur study reveals that TRPC6-Calpain1 axis promotes tubulointerstitial inflammation in DKD by inhibiting mitophagy.

Dapagliflozin restores autophagy and attenuates apoptosis via the AMPK/mTOR pathway in diabetic nephropathy rats and high glucose-induced HK-2 cells.

Diabetic nephropathy (DN) is a serious microvascular complication of diabetes mellitus. Significantly reduced levels of autophagy in diabetic kidneys play an important role in the development of DN. The present study investigated the effects of dapagliflozin (DAP) on renal autophagy and AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway in vivo and in vitro. We explored the effect of DAP in streptozotocin (STZ)-induced DN rats. The anti-DN effect of DAP was assessed by body weight, kidney weight/body weight ratio, blood and urine biochemical parameters, and pathological changes of kidney tissue. Number of autophagosomes in the kidney was investigated through Transmission electron microscopy. Besides, cell viability and apoptosis of DAP alone or combined with Compound C (CC, a selective AMPK inhibitor)-treated high glucose (HG)-induced HK-2 cells were detected by Cell Counting Kit-8 (CCK-8) and flow cytometry assays. Immunohistochemistry, Western blot, Enzyme-linked immunosorbent assay (ELISA), and immunofluorescence were employed to detect the expression levels of extracellular matrix (ECM) deposition, autophagy, apoptosis, and AMPK/mTOR pathway-associated targets in vivo and in vitro. The results showed that DAP ameliorated the body weight and decreased kidney weight, fasting blood glucose, and serum/urine biochemical parameters of renal damage, as well as renal pathological changes. Moreover, DAP significantly ameliorated HG-induced cell apoptosis and ECM deposition in HK-2 cells. However, these favorable effects of DAP could be abolished by co-treatment with CC in HG-induced HK-2 cells. Mechanistically, DAP can enhance autophagy in DN including increased LC3-II/I ratio, Beclin-1, p-AMPK protein levels, and decreased p62 and p-mTOR protein expressions, as well as inhibited renal fibrosis and apoptosis. In summary, DAP alleviated fibrosis, apoptosis, and autophagy in DN rats and HG-induced HK-2 cells by regulating the AMPK/mTOR pathway.

The angiotensin II/type 1 angiotensin II receptor pathway is implicated in the dysfunction of albumin endocytosis in renal proximal tubule epithelial cells induced by high glucose levels

It is well-established that dysfunction of megalin-mediated albumin endocytosis by proximal tubule epithelial cells (PTECs) and the activation of the Renin-Angiotensin System (RAS) play significant roles in the development of Diabetic Kidney Disease (DKD). However, the precise correlation between these factors still requires further investigation. In this study, we aimed to elucidate the potential role of angiotensin II (Ang II), a known effector of RAS, as the mediator of albumin endocytosis dysfunction induced by high glucose (HG) in PTECs. To achieve this, we utilized LLC-PK1 and HK-2 cells, which are well-established in vitro models of PTECs. Using albumin-FITC or DQ-albumin as tracers, we observed that incubation of LLC-PK1 and HK-2 cells with HG (25 mM for 48 h) significantly reduced canonical receptor-mediated albumin endocytosis, primarily due to the decrease in megalin expression. HG increased the concentration of Ang II in the LLC-PK1 cell supernatant, a phenomenon associated with an increase in angiotensin-converting enzyme (ACE) expression and a decrease in prolyl carboxypeptidase (PRCP) expression. ACE type 2 (ACE2) expression remained unchanged. To investigate the potential impact of Ang II on HG effects, the cells were co-incubated with angiotensin receptor inhibitors. Only co-incubation with 10−7 M losartan (an antagonist for type 1 angiotensin receptor, AT1R) attenuated the inhibitory effect of HG on albumin endocytosis, as well as megalin expression. Our findings contribute to understanding the genesis of tubular albuminuria observed in the early stages of DKD, which involves the activation of the Ang II/AT1R axis by HG.

Wnt-5a–Receptor Tyrosine Kinase-Like Orphan Receptor 2 Signaling Provokes Metastatic Colonization and Angiogenesis in Renal Cell Carcinoma, and Prunetin Supresses the Axis Activation

Wnt-5a is a protein that is encoded by the WNT5A gene and is a ligand for the ROR2 receptor. However, its biological impact on clear cell renal cell carcinoma (ccRCC) remains unclear. In this study, the prognostic significance of concurrent WNT5A and ROR2 expression levels was observed to predict unfavorable overall survival and disease-specific survival. High Wnt-5a expression was detected in a ccRCC cell line panel but not in HK-2 cells, a normal proximal tubular cell line. Inhibition of DNA methyltransferase by 5-azaC in 786-O and Caki-2 cells resulted in Wnt-5a upregulation, indicating potential epigenetic modification. Furthermore, the results revealed the repression of cell movement in vitro and metastatic colonization in vivo upon WNT5A and ROR2 knockdown. The suppressions of angiogenesis in vivo and tubular-like structure formation in endothelial cells in vitro were also observed after silencing WNT5A and ROR2 expression. In addition, alteration in the downstream gene signature of the Wnt-5a-ROR2 signaling was discovered to be similar to that in MTA1-CTNNB1 axis. Moreover, prunetin treatment was found to reverse the gene signature derived from Wnt-5a-ROR2 signaling activation and to abolish ccRCC cell migration and proliferation. Overall, this study demonstrates the clinical and functional significance of the Wnt-5a-ROR2 axis and identify prunetin as a potential precision medicine for ccRCC patients harboring aberrant Wnt-5a-ROR2 signaling pathways.

Rational design of an activatable dual-color fluorogenic probe for revealing the interaction of adenosine-5′-triphosphate and peroxynitrite in pyroptosis associated with acute kidney injury

ATP and ONOO- play unique roles in various biological events and exhibit notable interactions. To date, there is no available chemical tool for investigating the correlation between ATP and ONOO- concentrations in pyroptosis associated with acute kidney injury (AKI). Herein, we designed a novel dual-color near-infrared fluorescent (NIRF) probe P2 for simultaneous visualization of ATP and ONOO- both in vitro and in vivo. Unlike previously reported single-site fluorescent probes, P2 enabled concurrent imaging of ATP and ONOO- in two distinct fluorescence channels, with emission wavelengths centered at 585 and 690 nm, which greatly reduced spectral cross-talk. Employing a HK-2 pyroptosis model, a significant interaction between ATP and ONOO- was unveiled. Elevated ONOO- production was found to correlate with decreased ATP levels; conversely, an increase in ATP levels was associated with rapid ONOO- scavenging. Remarkably, P2 allowed the assessment of cellular hypoxia by monitoring ATP and ONOO- concentrations. The commercial ONOO--scavenger uric acid showcased a protective effect on HK-2 cells via inhibition of the cellular pyroptosis pathway. Furthermore, P2 was successfully employed for imaging of ATP and ONOO- in the AKI mice model. Our findings confirmed that renal ischemia-reperfusion triggered a rise in ONOO- levels, concurrent with a decline in ATP levels. Surprisingly, the cells exhibited a compensatory recovery of ATP levels as the reperfusion time was prolonged. These results suggested the newly devised P2, as a pivotal chemical tool for the simultaneous monitoring of ATP and ONOO-, might open new avenues for disease diagnosis and treatment.

MICT ameliorates hypertensive nephropathy by inhibiting TLR4/NF-κB pathway and down-regulating NLRC4 inflammasome.

Hypertensive nephropathy (HN) is one of the main causes of end-stage renal disease (ESRD), leading to serious morbidity and mortality in hypertensive patients. However, existing treatment for hypertensive nephropathy are still very limited. It has been demonstrated that aerobic exercise has beneficial effects on the treatment of hypertension. However, the underlying mechanisms of exercise in HN remain unclear. The spontaneously hypertensive rats (SHR) were trained for 8 weeks on a treadmill with different exercise prescriptions. We detected the effects of moderate intensity continuous training (MICT) and high intensity interval training (HIIT) on inflammatory response, renal function, and renal fibrosis in SHR. We further investigated the relationship between TLR4 and the NLRC4 inflammasome in vitro HN model. MICT improved renal fibrosis and renal injury, attenuating the inflammatory response by inhibiting TLR4/NF-κB pathway and the activation of NLRC4 inflammasome. However, these changes were not observed in the HIIT group. Additionally, repression of TLR4/NF-κB pathway by TAK-242 inhibited activation of NLRC4 inflammasome and alleviated the fibrosis in Ang II-induced HK-2 cells. MICT ameliorated renal damage, inflammatory response, and renal fibrosis via repressing TLR4/NF-κB pathway and the activation of NLRC4 inflammasome. This study might provide new references for exercise prescriptions of hypertension.

ESRRA modulation by empagliflozin mitigates diabetic tubular injury via mitochondrial restoration

BackgroundThe protection of the diabetic kidney by Empagliflozin (EMPA) is attributed to its interaction with the sodium glucose cotransporter 2 located on proximal tubular epithelial cells (PTECs). Estrogen-related receptor α (ESRRA), known for its high expression in PTECs and association with mitochondrial biogenesis, plays a crucial role in this process. This study aimed to explore the impact of ESRRA on mitochondrial mass in diabetic tubular injury and elucidate the mechanism underlying the protective effects of EMPA. MethodsMitochondrial changes in PTECs of 16-week-old diabetic mice were assessed using transmission electron microscopy (TEM) and RNA-sequences. In vivo, EMPA administration was carried out in db/db mice for 8 weeks, while in vitro experiments involved modifying ESRRA expression in HK2 cells using pcDNA-ESRRA or EMPA. ResultsEvaluation through TEM revealed reduced mitochondrial mass and swollen mitochondria in PTECs, whereas no significant changes were observed under light microscopy. Analysis of RNA-sequences identified 110 downregulated genes, including Esrra, associated with mitochondrial function. Notably, ESRRA overexpression rescued the loss of mitochondrial mass induced by high glucose (HG) in HK2 cells. EMPA treatment ameliorated the ultrastructural alterations and mitigated the downregulation of ESRRA both in db/db mice and HG-treated HK2 cells. ConclusionThe diminished expression of ESRRA is implicated in the decline of mitochondrial mass in PTECs during the early stages of diabetes, highlighting it as a key target of EMPA for preventing the progression of diabetic kidney injury.

Fucoidan from Laminaria japonica protects renal tubular epithelial cells from uric acid induced NLRP3-mediated pyroptosis through inhibition of NF-κB pathway

Ethnopharmacological relevanceHyperuricemia is a common metabolic disease with prominent morbidity, it can lead to many adverse effects and complications, such as chronic nephrosis. Fucoidan has been used as natural drug for acute and chronic kidney disease for over 20 years in China, but the precise mechanisms underlying the renal protective function are still indefinable. PurposeThis study is conducted to explore alleviation of fucoidan (FPS) from Laminaria japonica on urate-induced NOD-like receptor family, pyrin domain-containing 3 (NLRP3)-mediated pyroptosis in renal tubular epithelial cells HK-2, as well as the mechanism of nuclear factor κB (NF-κB) signaling pathway involved. Materials and methodsHK-2 cells were treated with FPS, uric acid (UA), and inhibitor of NF-κB signaling pathway. Nitric oxide (NO) content and inducible nitric oxide synthase (iNOS) activity were determined with detection kits. Activation of intercellular NLRP3 inflammasome and NF-κB signaling pathway, gasdermin D (GSDMD) expression level were evaluated with Western blot and quantitative reverse transcription-PCR (qRT-PCR), and immunofluorescent analysis. ResultsData showed that UA induced cellular inflammatory response demonstrated by elevated NO content, iNOS activity and expression level of NLRP3 inflammasome-mediated pyroptosis associated molecules including NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), Caspase-1, interleukin 18 (IL-18) and GSDMD, moreover the NF-κB signaling pathway was activated by UA. However, FPS exposure inhibited efficiently the UA induced adverse effect. ConclusionIt can be concluded that FPS inhibited UA-induced NLRP3-mediated pyroptosis in HK-2 cells through repressing NF-κB signaling pathway.

Astragaloside IV protects renal tubular epithelial cells against oxidative stress-induced injury by upregulating CPT1A-mediated HSD17B10 lysine succinylation in diabetic kidney disease.

Tubular injury and oxidative stress are involved in the pathogenesis of diabetic kidney disease (DKD). Astragaloside IV (ASIV) is a natural antioxidant. The effects and underlying molecular mechanisms of ASIV on DKD have not been elucidated. The db/db mice and high-glucose-stimulated HK2 cells were used to evaluate the beneficial effects of ASIV in vivo and in vitro. Succinylated proteomics was used to identify novel mechanisms of ASIV against DKD and experimentally further validated. ASIV alleviated renal dysfunction and proteinuria, downregulated fasting blood glucose, and upregulated insulin sensitivity in db/db mice. Meanwhile, ASIV alleviated tubular injury, oxidative stress, and mitochondrial dysfunction in vivo and in vitro. Mechanistically, ASIV reversed downregulated 17beta-hydroxysteroid dehydrogenase type 10 (HSD17B10) lysine succinylation by restoring carnitine palmitoyl-transferase1alpha (Cpt1a or CPT1A) activity in vivo and in vitro. Molecular docking and cell thermal shift assay revealed that ASIV may bind to CPT1A. Molecular dynamics simulations demonstrated K99 succinylation of HSD17B10 maintained mitochondrial RNA ribonuclease P (RNase P) stability. The K99R mutation of HSD17B10 induced oxidative stress and disrupted its binding to CPT1A or mitochondrial ribonuclease P protein 1 (MRPP1). Importantly, ASIV restored the interaction between HSD17B10 and MRPP1 in vivo and in vitro. We also demonstrated that ASIV reversed high-glucose-induced impaired RNase P activity in HK2 cells, which was suppressed upon K99R mutation of HSD17B10. These findings suggest that ASIV ameliorates oxidative stress-associated proximal tubular injury by upregulating CPT1A-mediated K99 succinylation of HSD17B10 to maintain RNase P activity.

Carbon dots encapsulated zeolitic imidazolate framework-8 as an enhanced multi-antioxidant for efficient cytoprotection to HK-2 cells

Excessive reactive oxygen species (ROS) can lead to the imbalance of antioxidant system in the body and cause oxidative damage to cells. It is imperative to rationally design nanomaterials with high catalytic activity and multiple antioxidant activities. Here, line peppers-derived carbon dots (CDs) is encapsulated into zeolitic imidazolate framework-8 (CDs@ZIF-8) to achieve enhanced antioxidant activities for improved protective effect on cells. This nanosystem has a broad spectrum of antioxidant properties, which can effectively remove a variety of intracellular ROS and protect cells from ROS-induced death and cytoskeleton damage. In addition, CDs@ZIF-8 can reduce malondialdehyde (MDA) level and increase the enzyme activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx), as well as the level of glutathione (GSH) in human kidney proximal tubular epithelial cells (HK-2) cells. Mechanism studies demonstrated that CDs@ZIF-8 can up-regulate the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), allowing the regulation of antioxidant enzymes to further achieve antioxidant effect. Besides, CDs@ZIF-8 inhibited the secretion of proinflammatory cytokines. This work demonstrates that the constructed CDs@ZIF-8 with multi-antioxidant activity can act as a highly efficient intracellular ROS scavenger and provide potential for the application in related oxidative stress-induced diseases.

High STING expression exacerbates renal ischemia-reperfusion injury in mice by regulating the TLR4/NF-κB/NLRP3 pathway and promoting inflammation and apoptosis

To investigate renal expression level of STING in mice with renal ischemia-reperfusion injury (IRI) and its regulatory role in IRI. C57BL/6 mice were divided into sham operation group, IRI (induced by clamping the renal artery) model group, IRI+DMSO treatment group, and IRI+SN-011 treatment group. Serum creatinine and blood urea nitrogen of the mice were analyzed, and pathological changes in the renal tissue were assessed with PAS staining. RT-qPCR, ELISA, Western blotting, and immunohistochemistry were used to detect the expression levels of STING, KIM-1, Bcl-2, Bax, caspase-3, TLR4, P65, NLRP3, caspase-1, CD68, MPO, IL-1β, IL-6, and TNF-α in the renal tissues. In the cell experiment, HK-2 cells exposed to hypoxia-reoxygenation (H/R) were treated with DMSO or SN-011, and cellular STING expression levels and cell apoptosis were analyzed using RT-qPCR, Western blotting or flow cytometry. In C57BL/6 mice, renal IRI induced obvious renal tissue damage, elevation of serum creatinine and blood urea nitrogen levels and renal expression levels of KIM-1, STING, TLR4, P65, NLRP3, caspase-1, caspase-3, Bax, CD68, MPO, IL-1β, IL-6, and TNF-α, and reduction of Bcl-2 expression level. Treatment of the mouse models with SN-011 for inhibiting STING expression significantly alleviated these changes. In HK-2 cells, H/R exposure caused significant elevation of cellular STING expression and obviously increased cell apoptosis rate, which was significantly lowered by treatment with SN-011. Renal STING expression is elevated in mice with renal IRI to exacerbate renal injury by regulating the TLR4/NF-κB/NLRP3 pathway and promoting inflammation and apoptosis in the renal tissues.

Spike lavender essential oil attenuates hyperuricemia and induced renal injury by modulating the TLR4/NF-κB/NLRP3 signalling pathway

Hyperuricemia (HUA), recognized as the fourth “high” condition following hypertension, hyperlipidemia, and hyperglycemia, is a metabolic disorder that severely impairs renal function. Spike lavender essential oil (SLEO) exhibits substantial anti-inflammatory and antioxidant activities and can inhibit xanthine oxidase (XOD), suggesting its potential therapeutic potential against HUA. This of this study aimed to analyze the chemical constituents of SLEO with potential efficacy in treating HUA and to explore their mechanisms of action. Gas chromatography-mass spectrometry (GC–MS) combined with a greedy algorithm identified linalool, β-pinene, and β-caryophyllene as key active components of SLEO. Through network pharmacology “weight coefficient” method, the NOD-like signaling pathway emerged as a significant mechanism for SLEO in treating HUA. Investigating an in vitro uric acid (UA)-induced HK-2 cell model revealed that SLEO effectively inhibited the production of IL-1β and IL-18 in the supernatant of HK-2 cells compared to the NLRP3 (antagonist MCC950). Additionally, a HUA rat model demonstrated that SLEO administration significantly reduced hyperuricemia pathological indicators, such as UA, XOD, and blood urea nitrogen (BUN) levels, with renal histopathological sections showing a marked reduction in following SLEO treatment. Metabolomics and transcriptomics analyses further highlighted significant changes in differential metabolites such as arachidonic acid and glycine, as well as the regulation of differential genes such as pycard and PTGS2 in rats.Immunohistochemistry, Western blotting, molecular docking and in vitro XOD activity inhibition assays elucidated the active components mechanisms of SLEO in treating HUA and associated renal inflammation. The findings concluded that SLEO mitigates HUA and renal inflammation by modulating the arachidonic acid metabolic pathway and the NF-κB signaling pathway. Moreover, linalool, β-pinene and β-caryophyllene in SLEO were shown to reduce UA production and lower UA levels in vivo by inhibiting the TLR4/NF-κB/NLRP3 pathway, thereby alleviating HUA-induced renal injury.

Gemigliptin mitigates TGF-β-induced renal fibrosis through FGF21-mediated inhibition of the TGF-β/Smad3 signaling pathway

Fibroblast growth factor 21 (FGF21), a well-known regulator of metabolic disorders, exhibits the potential to prevent renal fibrosis by negatively regulating the transforming growth factor β (TGF-β)/Smad3 signaling pathway. Gemigliptin and other dipeptidyl peptidase-4 inhibitors are frequently used for the management of patients with type 2 diabetes. However, the protective effect of gemigliptin against renal fibrosis, particularly its potential to upregulate the expression of FGF21, remains incompletely understood. This study assessed the renoprotective effects of gemigliptin against TGF-β-induced renal fibrosis by enhancing the expression of FGF21 in the cultured human proximal tubular epithelial cell line HK-2. Treatment with FGF21 effectively prevented TGF-β-induced renal fibrosis by attenuating the TGF-β/Smad3 signaling pathway. Similarly, gemigliptin exhibited protective effects against TGF-β-induced renal fibrosis by mitigating TGF-β/Smad3 signaling through the upregulation of FGF21 expression. However, the protective effects of gemigliptin were blocked when FGF21 expression was knocked down in TGF-β-treated HK-2 cells. These results indicate that gemegliptin has the potential to exhibit protective effects against TGF-β-induced renal fibrosis by elevating FGF21 expression levels in cultured human proximal tubular epithelial cells.

MicroRNA-223-3p Targeting SGK1 Regulates Apoptosis and Inflammation in Sepsis-Associated Acute Kidney Injury.

Sepsis and septic shock are significant contributors to the development of acute kidney injury (AKI) in critically ill patients. This study aimed to elucidate the role and mechanism of microRNA-223-3p in sepsis-associated AKI (SA-AKI). Bioinformatics methods were used to analyze the expression of microRNA-223-3p in sepsis patients, its correlation with inflammatory cytokines, and to predict the binding site of microRNA-223-3p with SGK1. The binding relationship between microRNA-223-3p and SGK1 was validated using a dual-luciferase reporter gene assay. The expression of microRNA-223-3p was assayed using qPCR in patient serum or lipopolysaccharide (LPS)-treated HK-2 cells. Cell apoptosis; expression of Bax, Bcl-2, cleaved caspase-3; and levels of TNF-α, IL-1β, and IL-6 were measured using TUNEL assay, Western blot (WB), and ELISA, respectively. SGK1 expression of HK-2 cells with different treatments was detected using qPCR and WB. The expression of microRNA-223-3p was found to be upregulated in sepsis patients and HK-2 cells treated with LPS. Furthermore, microRNA-223-3p promoted apoptosis and inflammation in LPS-induced HK-2 cells. This promotion was mediated by the negative regulation of SGK1 by microRNA-223-3p. The microRNA-223-3p was found to regulate SGK1 and promote apoptosis and inflammation in LPS-induced HK-2 cells. Our study has elucidated the mechanism of microRNA-223-3p in SA-AKI, providing a potential target for sepsis treatment.

Epithelial CEBPD activates fibronectin and enhances macrophage adhesion in renal ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) is a cause of acute kidney injury in patients after renal transplantation and leads to high morbidity and mortality. Damaged kidney resident cells release cytokines and chemokines, which rapidly recruit leukocytes. Fibronectin (FN-1) contributes to immune cell migration, adhesion and growth in inflamed tissues. CCAAT/enhancer-binding protein delta is responsive to inflammatory cytokines and stresses and plays functional roles in cell motility, extracellular matrix production and immune responses. We found that the expression of CCAAT/enhancer-binding protein delta was increased in renal epithelial cells in IRI mice compared with sham mice. Following IRI, the colocalization of FN-1 with the macrophage marker F4/80 was increased in renal injury model wild-type mice but was significantly attenuated in Cebpd-deficient mice. Inactivation of CEBPD can repress hypoxia-induced FN-1 expression in HK-2 cells. Moreover, the inactivation of CEBPD and FN-1 also reduces macrophage accumulation in HK-2 cells. These findings suggest that the involvement of CEBPD in macrophage accumulation through the activation of FN-1 expression and the inhibition of CEBPD can protect against renal IRI.

Quercetin Attenuates Acute Kidney Injury Caused by Cisplatin by Inhibiting Ferroptosis and Cuproptosis.

Ferroptosis, an iron- and ROS-dependent form of regulated cell death. Cuproptosis is a novel form of cellular demise mode. Quercetin, a natural flavonoid, has demonstrated a range of pharmacological activities, including anti-cancer, anti-inflammatory, and antioxidant properties. In this research, we investigated the quercetin effect on cisplatin-induced acute kidney and its mechanism associated ferroptosis and cuproptosis. The HK-2 cells were used in this research. Cell viability was evaluated using the CCK-8 assay. Acute kidney injury (AKI) models were established to perform in vivo experiments. Renal tissue homogenate was used to determine ROS, LPO, MDA, PA, etc., to assess ferroptosis and cuproptosis. To perform bioinformatic analysis, microarray data from the GEO database was utilized. Real-time PCR analysis and ELISA was explored the mechanism of ferroptosis and cuproptosis. We found that ferroptosis and cuproptosis in AKI were abnormally activated caused by cisplatin, and that quercetin attenuated AKI by inhibiting ferroptosis and cuproptosis. QCT suppressed ferroptosis by reducing malondialdehyde (MDA) and ROS levels and increasing glutathione (GSH) levels and alleviated cuproptosis by reducing copper ion, pyruvate (PA) and HSP70 levels. Moreover, bioinformatic analysis revealed that the ferroptosis-related gene SLC7A11 and the cuproptosis-related genes ATP7B and GLS were the differential expression genes. And QCT significantly increased the expression or activity of SLC7A11, GPX4, ATP7B, and GLS in Cis-AKI mice. Our findings highlight the clinical importance of quercetin, which guards against cisplatin-induced acute kidney injury by suppressing ferroptosis and cuproptosis.

Tetrahydrocurcumin Attenuates Polymyxin B Sulfate-Induced HK-2 Cells Apoptosis by Inhibiting Endoplasmic Reticulum Stress-Mediated PERK/eIF2α/ATF4/CHOP Signaling Pathway Axis.

The clinical application of polymyxin B (PMB) is limited by its nephrotoxic effects, making the reduction of PMB-induced nephrotoxicity has become a pressing concern for clinicians. Tetrahydrocurcumin (THC), known for its beneficial characteristics in biological functions, presents an attractive option for intervention therapy to mitigate PMB-induced nephrotoxicity. However, the underlying mechanism of how THC mitigates PMB-induced nephrotoxicity is still poorly understood. Here, we first evaluated the potential of THC intervention therapy to mitigate PMB-induced nephrotoxicity in an in vitro model of PMB-induced cell injury. Moreover, we demonstrated that THC effectively protected HK-2 cells from PMB-induced apoptosis by using cell counting kit-8 and flow cytometry assay. THC could also suppress PMB-induced endoplasmic reticulum (ER) stress via PERK/eIF2α/ATF4/CHOP pathway. In addition, using PERK inhibitor GSK2606414 to inhibit ER stress also alleviated PMB-induced apoptosis. Taken together, these findings provide novel insights that THC possesses the ability to alleviate PMB-induced nephrotoxicity by inhibiting the ER stress-mediated PERK/eIF2α/ATF4/CHOP axis, which sheds light on the benefits of THC as an intervention strategy to reduce PMB-induced nephrotoxicity, thus providing a potential avenue for improved clinical outcomes in patients receiving PMB treatment.