The potential role of aquaporin 1 on aristolochic acid I induced epithelial mesenchymal transition on HK-2 cells

LYC inhibits the AKT signaling pathway to activate autophagy and ameliorate TGFB-induced renal fibrosis

Renal fibrosis is a typical pathological change in chronic kidney disease (CKD). Epithelial-mesenchymal transition (EMT) is the predominant stage. Activation of macroautophagy/autophagy plays a crucial role in the process of EMT. Lycopene (LYC) is a highly antioxidant carotenoid with pharmacological effects such as anti-inflammation, anti-apoptosis and mediation of autophagy. In this study, we demonstrated the specific mechanism of LYC in activating mitophagy and improving renal fibrosis. The enrichment analysis results of GO and KEGG showed that LYC had high enrichment values with autophagy. In this study, we showed that LYC alleviated aristolochic acid I (AAI)-induced intracellular expression of PINK1, TGFB/TGF-β, p-SMAD2, p-SMAD3, and PRKN/Parkin, recruited expression of MAP1LC3/LC3-II and SQSTM1/p62, decreased mitochondrial membrane potential (MMP), and ameliorated renal fibrosis in mice. When we simultaneously intervened NRK52E cells using bafilomycin A1 (Baf-A1), AAI, and LYC, intracellular MAP1LC3-II and SQSTM1 expression was significantly increased. A similar result was seen in renal tissue and cells when treated in vitro and in vivo with CQ, AAI, and LYC, and the inhibitory effect of LYC on the AAI-activated SMAD2-SMAD3 signaling pathway was attenuated. Molecular docking simulation experiments showed that LYC stably bound to the AKT active site. After intervention of cells with AAI and GSK-690693, the expression of PINK1, PRKN, MAP1LC3-II, BECN1, p-SMAD2 and p-SMAD3 was increased, and the expression of SQSTM1 was decreased. However, SC79 inhibited autophagy and reversed the inhibitory effect of LYC on EMT. The results showed that LYC could inhibit the AKT signaling pathway to activate mitophagy and reduce renal fibrosis.Abbreviation: AA: aristolochic acid; ACTA2/α-SMA: actin alpha 2, smooth muscle, aorta; ACTB: actin beta; AKT/protein kinase B: thymoma viral proto-oncogene; BAF-A1: bafilomycin A1; BECN1: beclin 1, autophagy related; CCN2/CTGF: cellular communication network factor 2; CDH1/E-Cadherin: cadherin 1; CKD: chronic kidney disease; COL1: collagen, type I; COL3: collagen, type III; CQ: chloroquine; ECM: extracellular matrix; EMT: epithelial-mesenchymal transition; FN1: fibronectin 1; LYC: lycopene; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MMP: mitochondrial membrane potential; MTOR: mechanistic target of rapamycin kinase ; PI3K: phosphoinositide 3-kinase; PINK1: PTEN induced putative kinase 1; PRKN/Parkin: parkin RBR E3 ubiquitin protein ligase; PPI: protein-protein interaction; SMAD2: SMAD family member 2; SMAD3: SMAD family member 3; SQSTM1/p62: sequestosome 1; TGFB/TGFβ: transforming growth factor, beta; VIM: vimentin.

Shen Qi Wan attenuates renal interstitial fibrosis through upregulating AQP1

Renal interstitial fibrosis (RIF) is the crucial pathway in chronic kidney disease (CKD) leading to the end-stage renal failure. However, the underlying mechanism of Shen Qi Wan (SQW) on RIF is not fully understood. In the current study, we investigated the role of Aquaporin 1 (AQP1) in SQW on tubular epithelial-to-mesenchymal transition (EMT). A RIF mouse model induced by adenine and a TGF-β1-stimulated HK-2 cell model were etablished to explore the involvement of AQP 1 in the protective effect of SQW on EMT in vitro and in vivo. Subsequently, the molecular mechanism of SQW on EMT was explored in HK-2 cells with AQP1 knockdown. The results indicated that SQW alleviated kidney injury and renal collagen deposition in the kidneys of mice induced by adenine, increased the protein expression of E-cadherin and AQP1 expression, and decreased the expression of vimentin and α-smooth muscle actin (α-SMA). Similarly, treatmement with SQW-containing serum significantly halted EMT process in TGF-β1 stimulated HK-2 cells. The expression of snail and slug was significantly upregulated in HK-2 cells after knockdown of AQP1. AQP1 knockdown also increased the mRNA expression of vimentin and α-SMA, and decreased the expression of E-cadherin. The protein expression of vimentin increased, while the expression of E-cadherin and CK-18 significantly decreased after AQP1 knockdown in HK-2 cells. These results revealed that AQP1 knockdown promoted EMT. Furthermore, AQP1 knockdown abolished the protective effect of SQW-containing serum on EMT in HK-2 cells. In sum, SQW attentuates EMT process in RIF through upregulation of the expression of AQP1.

Aquaporins in Urinary System

There are at least eight aquaporins (AQPs) expressed in the kidney. Including AQP1 expressed in proximal tubules, thin descending limb of Henle and vasa recta; AQP2, AQP3, AQP4, AQP5, and AQP6 expressed in collecting ducts; AQP7 expressed in proximal tubules; AQP8 expressed in proximal tubules and collecting ducts; and AQP11 expressed in the endoplasmic reticulum of proximal tubular epithelial cells. Over years, researchers have constructed different AQP knockout mice and explored the effect of AQP knockout on kidney function. Thus, the roles of AQPs in renal physiology are revealed, providing very useful information for addressing fundamental questions about transepithelial water transport and the mechanism of near isoosmolar fluid reabsorption. This chapter introduces the localization and function of AQPs in the kidney and their roles in different kidney diseases to reveal the prospects of AQPs in further basic and clinical studies.

Lycopene attenuates the inflammation and apoptosis in aristolochic acid nephropathy by targeting the Nrf2 antioxidant system

Lycopene (LYC) is a carotenoid, has antioxidant properties. This study investigated whether lycopene attenuates aristolochic acids (AAs) -induced chronic kidney disease. In this experiment, lycopene was used to intervene C57BL/6 mice with renal injury induced by aristolochic acid exposure. The histomorphological changes and serological parameters of the kidney were measured in order to assess the alleviating effect of lycopene on renal injury in aristolochic acid nephropathy. In vitro and in vivo experiments were carried out to verify the main mechanism of action and drug targets of lycopene in improving aristolochic acid nephropathy (AAN) and by various experimental methods such as ELISA, immunohistochemistry, immunofluorescence, Western-blot and qRT-PCR. The results showed that oxidative stress injury was induced in the kidney of mice after AAI exposure, resulting in inflammatory response and tubular epithelial cell apoptosis. The results showed that the Nrf2/HO-1 antioxidant signaling pathway was inhibited after AAI exposure. AAI induces oxidative stress injury in the kidney, which ultimately leads to inflammation and tubular epithelial cell apoptosis. After LYC intervened in the body, it activated Nrf2 nuclear translocation and its downstream HO-1 and NQO1 antioxidant signaling pathways. LYC inhibited ROS production by renal tubular epithelial cells, and alleviated mitochondrial damage. LYC further modulated the TNF-α/NF-κB signaling cascade, thereby reduced the accumulation of inflammatory factors in the renal interstitium. Moreover, LYC was able to up-regulate the expression of Bcl-2, down-regulate Bax expression and inhibit the activation of cleaved forms of Caspase-9 and Caspase-3, which finally attenuated the apoptosis of the mitochondrial pathway induced by AAI exposure. It was concluded that lycopene was able to activate the Nrf2 antioxidant signaling pathway to maintain the homeostasis of renal oxidative stress and ultimately attenuated renal inflammatory response and apoptosis. These results suggested that lycopene can be used as a drug to relieve AAN.

Integrated single-cell transcriptomics and proteomics reveal cellular-specific response and microenvironment remodeling in aristolochic acid nephropathy

Aristolochic acid nephropathy (AAN) is characterized by acute proximal tubule necrosis and immune cell infiltration, contributing to the global burden of chronic kidney disease and urothelial cancer. Although the proximal tubule has been defined as the primary target of aristolochic acids I (AAI), the mechanistic underpinning of gross renal deterioration caused by AAI has not been explicitly explained, prohibiting effective therapeutic intervention. To this point, we employed integrated single-cell RNA-Seq, bulk RNA-Seq, and mass spectrometry–based proteomics to analyze the mouse kidney after acute AAI exposure. Our results reveal a dramatic reduction of proximal tubule epithelial cells, associated with apoptotic and inflammatory pathways, indicating permanent damage beyond repair. We found the enriched development pathways in other nephron segments, suggesting activation of reparative programs triggered by AAI. The divergent response may be attributed to the segment-specific distribution of organic anion channels along the nephron, including OAT1 and OAT3. Moreover, we observed dramatic activation and recruitment of cytotoxic T and macrophage M1 cells, highlighting inflammation as a principal contributor to permanent renal injury. Ligand-receptor pairing revealed that critical intercellular crosstalk underpins damage-induced activation of immune cells. These results provide potentially novel insight into the AAI-induced kidney injury and point out possible pathways for future therapeutic intervention.

Ginsenoside Rb1 Ameliorated Bavachin-Induced Renal Fibrosis via Suppressing Bip/eIF2α/CHOP Signaling-Mediated EMT

The nephrotoxicity of Fructus Psoraleae, an effective traditional Chinese medicine for vitiligo treatment, has been reported. As one of the main toxic components in Fructus Psoraleae, bavachin (BV) was considered to be related to Fructus Psoraleae-caused adverse outcomes, but the direct evidence and molecular mechanism underlying BV-induced nephrotoxicity are not well elucidated. Therefore, this study was designed to confirm whether BV would cause toxic effects on the kidney and explore the possible mode of action. Our results demonstrated that days’ treatment with 0.5 μM BV indeed caused obvious renal fibrosis in the zebrafish kidney. The obvious E- to N-cadherin switch and the expressions of proteins promoting epithelial–mesenchymal transition (EMT) were observed in BV-treated human renal tubular epithelial and zebrafish kidneys. In addition, elevated reactive oxygen species (ROS) levels and Bip/eIF2α/CHOP-mediated endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) were caused by BV, both of which could be reversed by ROS scavenger N-acetyl-L-cysteine (NAC). Also, blocking ER stress-caused cytoplasmic Ca2+ overload with 4-PBA notably alleviated BV-induced alterations in key molecular events related to EMT and renal fibrosis. Furthermore, of the natural compounds subjected to screening, ginsenoside Rb1 significantly downregulated BV-induced ER stress by inhibiting ROS generation and following the activation of Bip/eIF2α/CHOP signaling in HK2 cells. Subsequently, BV-triggered EMT and renal fibrosis were both ameliorated by ginsenoside Rb1. In summary, our findings suggested that BV-induced ROS promoted the appearance of EMT and renal fibrosis mainly via Bip/eIF2α/CHOP-mediated ER stress. This ER stress-related toxic pathway might be a potential intervention target for BV-caused renal fibrosis, and ginsenoside Rb1 would be a promising drug against BV- or Fructus Psoraleae-induced nephrotoxicity.

An investigation on nephrotoxicity of Aristolactam I induced epithelial-mesenchymal transition on HK-2 cells

Aristolactam I (AL-I) is the main active ingredient in the Aristolochia plant species, which have been associated with severe nephrotoxicity. In order to investigate the mechanism of AL-I induced renal epithelial-mesenchymal transition (EMT), we established an AL-I induced EMT model in human proximal tubular epithelial cells (HK-2 cells). Biochemical analysis experiment including Morphological examination, 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide assay, and Western blot analysis were performed. The results showed that AL-I accumulates in the cytosol causing cytotoxicity and inhibition of proliferation in a concentration- and time-dependent manner. Morphological examination showed that with the increasing concentration of AL-I, the tendency of HK-2 cells transform form epithelial cell to fibroblast cells was stronger. In the Western blot analysis, the expression of α-Smooth muscle actin (α-SMA) and Transforming Growth Factor β1 (TGF-β1) were significantly up-regulated, the expression of E-cadherin was significantly down-regulated after administrating. The ratio of the expression of P-Smad2/3 and Smad2/3 was significantly up-regulated, suggested that TGF-β/Smad-dependent signaling pathway was activated in this process. With presence of TGF-β receptor inhibitor (LY364947), we found that the expressions of three EMT related proteins (E-cadherin, α-SMA and TGF-β1) were obviously reversed. In conclusion, we acknowledge that AL-I can induce renal EMT process in HK-2 cell, which is triggered by the activation of TGF-β/Smad-dependent signaling pathway.

Integration of transcriptomic, proteomic and metabolomic data to reveal the biological mechanisms of AAI injury in renal epithelial cells

Overexposure to aristolochic acid I (AAI) can induce aristolochic acid nephropathy (AAN). However, the comprehensive mechanisms of AAI-induced nephrotoxicity have not been entirely explicated. To investigate the toxicological mechanisms by which AAI induces renal injury, human kidney cells (HK-2 cells) were subjected to comprehensive transcriptomic, proteomic and metabolomic analyses. The transcriptomic analysis identified a total of 7749 differentially expressed genes (DEGs) after AAI treatment, while the proteomic analysis found 598 differentially expressed proteins (DEPs) after AAI treatment. The metabolomic analysis revealed 49 and 42 differentially expressed metabolites (DEMs) in the positive and negative ion modes, respectively. Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed on these DEGs, DEPs and DEMs. The results of the comprehensive analyses of transcripts, proteins, and metabolites indicated that the DEGs, DEPs, and DEMs were jointly regulated in three ways. These genes, proteins and metabolites and their related dysregulated pathways may be promising targets for research on the mechanisms of AAI injury in human renal epithelial cells. This study provides large-scale omics data that can be used to formulate new strategies for the prevention, rapid diagnosis, and treatment of AAI injury.

Nephrotoxicity of Herbal Medicine and Its Prevention

Herbal medicine (HM) has been widely used to treat diseases for thousands of years and has greatly contributed to the health of human beings. Many new drugs have been developed from HM, such as artemisinin. However, artemisinin has adverse effects, such as renal toxicity. In 1993, a study conducted in Belgium reported for the first time that the root extracts of Aristolochia obliqua S. M. Hwang led to progressive interstitial renal fibrosis. The nephrotoxicity of HM has attracted worldwide attention. More than 100 kinds of HM induce renal toxicity, including some herbs, animal HMs, and minerals. This paper aimed to summarize the HM compounds that cause nephrotoxicity, the mechanisms underlying the toxicity of these compounds, biomarkers of renal injury, and prevention strategies. These findings provide a basis for follow-up studies on the prevention and treatment of HM nephrotoxicity.

Aquaporin 1 alleviates acute kidney injury via PI3K-mediated macrophage M2 polarization

BACKGROUND

Lipopolysaccharide (LPS)-induced acute kidney injury (AKI) is associated with an abnormal immune response. Accumulating evidence has demonstrated that aquaporin 1 (AQP1) prevents kidney tissue injury in LPS-induced AKI by mediating immune response. However, the underlying mechanisms remain obscure. Macrophages as immune cells with multiple phenotypes are important mediators in tissue homeostasis and host defense. We propose that macrophage polarization is implicated in AQP1-mediated immune response.

METHODS

Herein we established sepsis-induced AKI model rats through intraperitoneal injection of LPS into Wistar rats to reveal immune mechanism of damage. We also used LPS-induced mouse RAW264.7 cells to elucidate the molecular mechanism of macropage polarization.

RESULTS

Histopathology showed that renal tubular epithelial cells in the model group were swollen, inflammatory exudation was obvious and the inflammatory factors, interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) were increased. Western blotting showed PI3K was upregulated in the model group. Serum creatinine and urea nitrogen increased after LPS injection. Renal AQP1 mRNA is downregulated and serum AQP1 protein increased first and then decreased in LPS-induced AKI rats. M2 macrophage markers (Arg-1, CD206) were increased in repair stage. In addition, treatment of murine macrophages (RAW264.7) with AQP1 siRNA resulted in decreased PI3K activation and M2 polarization, but increased IL-6 and TNF-α. Moreover, inhibiting PI3K with wortmannin imitated the results of AQP1 silencing.

CONCLUSIONS

Macrophage M2 polarization is likely the cellular mechanism underlying the anti-AKI property of AQP1, and PI3K activation is involved in the AQP1-induced M2 phenotype switch.

Blockade of the mTOR signaling pathway with rapamycin ameliorates aristolochic acid nephropathy

Chronic aristolochic acid nephropathy (CAAN) is characterized by widespread apoptosis and interstitial fibrosis, which severely impairs kidney function. mTOR is crucial for cell proliferation and protein synthesis. In the present study, the therapeutic effects of blockade of mTOR activity by rapamycin on aristolochic acid nephropathy were investigated. In vitro experiments to determine cell apoptosis and cell cycle alterations caused by aristolochic acid (AA)-induced injury were conducted on three groups of cells: Untreated control, AAI (treated with aristolochic acid I), and AAI + rapamycin (RMS). In vivo experiments were conducted in a CAAN mouse model. One group of mice was treated with AAI (the CAAN group), while another group was treated with AAI and rapamycin (the treatment group). Kidney function and pathological changes in these mice were assessed by serum creatinine and urea nitrogen analysis. Hematoxylin and eosin staining of renal tissue was performed to evaluate the treatment effects of rapamycin. Western blotting and immunohistochemical staining were used to explore the mechanisms by which rapamycin inhibited cell proliferation, apoptosis and tissue fibrosis. In the in vitro experiments, rapamycin prevented AAI-induced cell apoptosis and G₂/M checkpoint cell cycle arrest. In the in vivo experiments, the treatment group exhibited lower serum creatinine and urea nitrogen, less extensive tubular atrophy and increased amount of glomerulus. Additionally, western blotting and immunohistochemical staining showed that the treatment group exhibited decreased expression levels of fibrosis-, proliferation- and apoptosis-related proteins compared with the CAAN group. The findings suggest that rapamycin can ameliorate kidney injury induced by AAI via blockade of mTOR, and thus could be a therapeutic strategy for patients with CAAN.

AQP1 suppression by ATF4 triggers trabecular meshwork tissue remodelling in ET-1-induced POAG

Primary open‐angle glaucoma (POAG) is the second leading cause of irreversible blindness worldwide. Increased endothelin‐1 (ET‐1) has been observed in aqueous humour (AH) of POAG patients, resulting in an increase in the out‐flow resistance of the AH. However, the underlining mechanisms remain elusive. Using established in vivo and in vitro POAG models, we demonstrated that water channel Aquaporin 1 (AQP1) is down‐regulated in trabecular meshwork (TM) cells upon ET‐1 exposure, which causes a series of glaucomatous changes, including actin fibre reorganization, collagen production, extracellular matrix deposition and contractility alteration of TM cells. Ectopic expression of AQP1 can reverse ET‐1‐induced TM tissue remodelling, which requires the presence of β‐catenin. More importantly, we found that ET‐1‐induced AQP1 suppression is mediated by ATF4, a transcription factor of the unfolded protein response, which binds to the promoter of AQP1 and negatively regulates AQP1 transcription. Thus, we discovered a novel function of ATF4 in controlling the process of TM remodelling in ET‐1‐induced POAG through transcription suppression of AQP1. Our findings also detail a novel pathological mechanism and a potential therapeutic target for POAG.

Chitinase-like protein YKL-40 regulates human bronchial epithelial cells proliferation, apoptosis, and migration through TGF-β1/Smads pathway

In order to study the effects of chitinase-like protein YKL-40 on proliferation, apoptosis, and migration of human bronchial epithelial cell line (BEAS-2B), and the underlying mechanisms, we cultured BEAS-2B alone or with different concentrations of YKL-40. thiazolyl blue tetrazolium bromide (MTT) assay was used to examine the cell proliferation. Annexin V-fluorescein isothiocyanate isomer (FITC)/propidium iodide staining and scratch assay were performed to test the cell apoptosis and migration. The concentrations of transforming growth factor-β1 (TGF-β1), Smad3, Smad7, alpha-smooth muscle actin (α-SMA), interleukin-4 (IL-4), IL-6, and IL-8 in the cell culture supernatant were detected by enzyme-linked immunosorbent assay. The messenger RNA and protein levels of YKL-40, TGF-β1, Smad3, Smad7, and α-SMA were detected by reverse transcription polymerase chain reaction and Western blot. BEAS-2B cells cultured with different concentrations of YKL-40 showed significantly higher cell proliferation and migration and inflammatory cytokines compared with that of control group, while the cell apoptosis was significantly lower than that of control group (p < 0.05). In addition, BEAS-2B cells cultured with YKL-40 had increased TGF-β1, Smad3, Smad7, and α-SMA levels in the supernatant, compared with that of BEAS-2B cells cultured alone (p < 0.05). Furthermore, LY364947, as TGF-β1/Smads signaling pathway inhibitor, decreased cell proliferation and migration ability and enhanced cell apoptosis of BEAS-2B cells compared with control group (p < 0.05). However, YKL-40 administration reversed the effect of LY364947 on the biological behavior of BEAS-2B cells. YKL-40 could affect the biological behaviors of BEAS-2B cells, which might be related to the TGF-β1/Smads pathway.

Aquaporins in Renal Diseases

Aquaporins (AQPs) are a family of highly selective transmembrane channels that mainly transport water across the cell and some facilitate low-molecular-weight solutes. Eight AQPs, including AQP1, AQP2, AQP3, AQP4, AQP5, AQP6, AQP7, and AQP11, are expressed in different segments and various cells in the kidney to maintain normal urine concentration function. AQP2 is critical in regulating urine concentrating ability. The expression and function of AQP2 are regulated by a series of transcriptional factors and post-transcriptional phosphorylation, ubiquitination, and glycosylation. Mutation or functional deficiency of AQP2 leads to severe nephrogenic diabetes insipidus. Studies with animal models show AQPs are related to acute kidney injury and various chronic kidney diseases, such as diabetic nephropathy, polycystic kidney disease, and renal cell carcinoma. Experimental data suggest ideal prospects for AQPs as biomarkers and therapeutic targets in clinic. This review article mainly focuses on recent advances in studying AQPs in renal diseases.

JAM-A knockdown accelerates the proliferation and migration of human keratinocytes, and improves wound healing in rats via FAK/Erk signaling

Junctional adhesion molecule-A (JAM-A) belongs to the immunoglobulin superfamily, it predominantly exists at the tight junctions of epithelial and endothelial cells. JAM-A is known to regulate leukocyte trans-endothelial migration, however, how it affects the proliferation and migration of keratinocytes, the two essential steps during wound healing, has less been explored. In this study, we showed that JAM-A was significantly expressed in normal skin epidermis. RNAi-mediated JAM-A knockdown remarkably promoted the proliferation and migration of keratinocytes. We also found that loss of JAM-A increased the protein levels of p-FAK, p-Erk1/2, and p-JNK; however, FAK inhibitor PF-562271 restrained the expression of p-FAK and p-Erk1/2 elevated by JAM-A RNAi, but not p-JNK, and also slowed down keratinocyte proliferation and migration. Finally, in a rat wound model we showed that absence of JAM-A significantly promoted the wound healing process, while the use of PF-562271 or Erk1/2 inhibitor PD98059 repressed those effects. These data collectively demonstrate that suppressing JAM-A expression could promote the proliferation and migration of keratinocytes and accelerate the healing process of rat skin wounds, potentially via FAK/Erk pathway, indicating that JAM-A might serve as a potential therapeutic target for the treatment of chronic refractory wounds.

Cytoprotective effect of aquaporin 1 against lipopolysaccharide-induced apoptosis and inflammation of renal epithelial HK-2 cells

Sepsis is the most common underlying disease of disseminated intravascular coagulation. Acute kidney injury is a common and serious complications of sepsis. In the present study, a lipopolysaccharide (LPS)-induced human proximal tubule cell line (HK-2 cells) was selected as an in vitro model of septic acute kidney injury. The aim of the present study was to investigate whether aquaporin 1 (AQP-1) has a cytoprotective role in LPS-induced HK-2 cells. HK-2 cells were treated with 0-16 µg/ml LPS for 0-24 h to establish the in vitro model of sepsis. The results demonstrated that AQP-1 levels were the lowest of the eight AQP genes expressed in LPS-induced HK-2 cells. Prior to LPS treatment, HK-2 cells were transfected with pcDNA-AQP-1 or small interfering-AQP-1 and cell counting kint-8 and flow cytometry assays were performed to assess cell viability and apoptosis rate, respectively. Changes in the expression of proinflammatory cytokines and chemokines, as well as important factors in the p38, extracellular signal-regulated kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK) pathways, were assessed using reverse transcription-quantitative polymerase chain reaction, western blotting and ELISA, respectively. LPS treatment reduced viability, increased apoptosis and upregulated the expression of proinflammatory cytokines and chemokines in HK-2 cells. AQP-1 overexpression significantly reversed the effects of LPS and downregulated the expression of tumor necrosis factor-α, interleukin (IL)-8, IL-1β and monocyte chemoattractant protein-1. The p38, ERK1/2 and JNK pathways were activated by LPS; however, the p38 and ERK1/2 pathways were blocked in AQP-1-overexpressing cells. AQP-1 overexpression was demonstrated to confer a survival advantage to LPS-injured HK-2 cells by controlling cell viability, apoptosis and inflammation, possibly via modulation of the p38 and ERK1/2 pathways. The results of the present study suggest that AQP-1 may be an effective treatment for acute kidney injury caused by sepsis.