Tacrolimus-Induced Renal Injury Research Articles

Linagliptin ameliorates tacrolimus-induced renal injury: role of Nrf2/HO-1 and HIF-1α/CTGF/PAI-1

BackgroundTacrolimus (TAC) is a frequently used immunosuppressive medication in organ transplantation. However, its nephrotoxic impact limits its long-term usage. This study aims to investigate the effect of linagliptin (Lina) on TAC-induced renal injury and its underlying mechanisms.Methods and resultsThirty-two Sprague Dawley rats were treated with TAC (1.5 mg/kg/day, subcutaneously) and/or Lina (5 mg/kg/day, orally) for 4 weeks. Histological examination was conducted, and serum and urinary biomarkers were measured to assess kidney function and integrity. Furthermore, ELISA, Western blot analysis and immunohistochemical assay were employed to determine signaling molecules of oxidative stress, profibrogenic, hypoxic, and apoptotic proteins. Tacrolimus caused renal dysfunction and histological deterioration evidenced by increased serum creatinine, blood urea nitrogen (BUN), urinary cystatin C, and decreased serum albumin as well as elevated tubular injury and interstitial fibrosis scores. Additionally, TAC significantly increased the expression of collagen type-1, alpha-smooth muscle actin (α-SMA), plasminogen activator inhibitor-1 (PAI-1), and transforming growth factor-beta1 (TGF-β1) renal content. Moreover, TAC decreased the expression of nuclear factor erythroid-2-related factor2 (Nrf2), heme oxygenase 1 (HO-1), and mitochondrial superoxide dismutase (SOD2). In addition, TAC increased protein expression of hypoxia-inducible factor1-alpha (HIF-1α), connective tissue growth factor (CTGF), inducible nitric oxide synthase (iNOS), 8-hydroxy-2-deoxyguanosine (8-OHdG), as well as nitric oxide (NO), 4-hydroxynonenal, caspase-3 and Bax renal contents. Furthermore, TAC decreased Bcl-2 renal contents. The Lina administration markedly attenuated these alterations.ConclusionLina ameliorated TAC-induced kidney injury through modulation of oxidative stress, hypoxia, and apoptosis related proteins.

The Mineralocorticoid Receptor on Smooth Muscle Cells Promotes Tacrolimus-Induced Renal Injury in Mice.

Tacrolimus (Tac) is a calcineurin inhibitor commonly used as an immunosuppressor after solid organ transplantation. However, Tac may induce hypertension, nephrotoxicity, and an increase in aldosterone levels. The activation of the mineralocorticoid receptor (MR) is related to the proinflammatory status at the renal level. It modulates the vasoactive response as they are expressed on vascular smooth muscle cells (SMC). In this study, we investigated whether MR is involved in the renal damage generated by Tac and if the MR expressed in SMC is involved. Littermate control mice and mice with targeted deletion of the MR in SMC (SMC-MR-KO) were administered Tac (10 mg/Kg/d) for 10 days. Tac increased the blood pressure, plasma creatinine, expression of the renal induction of the interleukin (IL)-6 mRNA, and expression of neutrophil gelatinase-associated lipocalin (NGAL) protein, a marker of tubular damage (p < 0.05). Our study revealed that co-administration of spironolactone, an MR antagonist, or the absence of MR in SMC-MR-KO mice mitigated most of the unwanted effects of Tac. These results enhance our understanding of the involvement of MR in SMC during the adverse reactions of Tac treatment. Our findings provided an opportunity to design future studies considering the MR antagonism in transplanted subjects.

Glycyrrhizic acid improves tacrolimus-induced renal injury by regulating autophagy.

Tacrolimus (TAC)-induced renal injury is detrimental to long-term kidney function, but a treatment medication is not available. Glycyrrhizic acid (GA) is an active ingredient in licorice widely used to treat kidney disease. Thus, this study explored the mechanisms of renoprotection by GA on TAC-induced renal injury. C57BL/6 mice were subjected daily to TAC or a combination of TAC and GA for 4 weeks, and then renal function, histopathology, and autophagy were assessed to examine the effect of GA on a renal injury. Next, Human kidney proximal tubular epithelial (HK-2) cells were pretreated with GA for 2h and then treated with TAC for 24 h. The effect of GA on TAC-induced HK-2 cell injury was assessed by measuring cell viability, apoptosis, autophagy, and lysosomes. Mice exposed to TAC and treated with GA had significantly greater improvements in renal function and tubulointerstitial fibrosis in comparison to mice not treated with GA. In addition, fibrosis-related protein expression, including α-smooth muscle actin and fibronectin, decreased after GA treatment. GA treatment also relieved autophagic clearance in TAC-induced renal injury. Several in vitro studies found that TAC inhibited cell viability, autophagy, lysosomal acidification, and promoted apoptosis. However, these results were less pronounced with GA pretreatment. In addition, bafilomycin A1 (which inhibits lysosomal function) reduced the protective effect of GA, indicating that lysosomal function plays an important role in this effect. Our data suggest that GA improves lysosomal function and regulates autophagy to protect against TAC-induced renal injury.

Exogenous pancreatic kininogenase protects against tacrolimus-induced renal injury by inhibiting PI3K/AKT signaling: The role of bradykinin receptors

BackgroundTissue kallikrein offers a wide spectrum of biological activity in the protection against various types of injury. However, information on its role in tacrolimus (TAC)-induced renal injury is limited. ObjectivesThis study aimed to assess the beneficial effects of pancreatic kininogenase (PK) in a rat model of chronic TAC nephrotoxicity and in vitro. MethodsSprague Dawley rats were treated daily with either TAC or PK or a combination of the two for four weeks. The influence of PK on renal injury was examined in terms of renal function, histopathology, cytokine expression, oxidative stress, intracellular organelles, programmed cell death, and PI3K/AKT signaling. Human kidney proximal tubular (HK-2) cells and mouse mesangial (SV40 MES13) cells treated with TAC and PK were also studied. ResultsPK treatment improved renal function and histopathology. This effect was paralleled by downregulation of proinflammatory and profibrotic cytokine expression. TAC-induced oxidative stress was closely associated with endoplasmic reticulum stress and mitochondrial dysfunction, resulting in excessive programmed cell death (apoptosis and autophagy) that was significantly abrogated by concurrent PK interference with PI3K/AKT signaling. PK also stimulated bradykinin receptor 1 (B1R) and B2R mRNA synthesis and increased bioactive nitric oxide (NO) and cAMP concentrations in TAC-treated kidneys. Blockade of either B1R or B2R eliminated the renoprotective effects of PK. In HK-2 and SV40 MES13 cells, PK decreased TAC-induced overproduction of intracellular reactive oxygen species and inhibited apoptotic cells, whereas cell viability was improved. Moreover, activated PI3K/AKT signaling in HK-2 cells was inhibited by PK and the PI3K inhibitor, LY294002. ConclusionsThese findings indicate that PK treatment protects against chronic TAC nephrotoxicity via inhibition of PI3K/AKT signaling.

Impact of the ACE2 activator xanthenone on tacrolimus nephrotoxicity: Modulation of uric acid/ERK/p38 MAPK and Nrf2/SOD3/GCLC signaling pathways

AimsThe calcineurin inhibitor tacrolimus is an effective and widely used immunosuppressant after organ transplantation to reduce graft rejection. However, its nephrotoxic effect could compel the patients to treatment discontinuation. The beneficial effects of angiotensin-converting enzyme 2 (ACE2) on the kidney and other organs have been investigated in several studies, but its role in tacrolimus nephrotoxicity still needs to be elucidated. Our study was designed to investigate effects of the ACE2 activator xanthenone on tacrolimus-induced renal injury. Materials and methodsMale Wistar rats were administered xanthenone (2 mg/kg) concurrently with tacrolimus (1 mg/kg) for 3 weeks, then blood and kidney tissue samples were collected for biochemical and molecular investigations. Key findingsCo-administration of xanthenone significantly improved renal functions in tacrolimus-treated rats, where serum creatinine, urea, and uric acid levels were close to those of the normal control. Besides, xanthenone reduced renal angiotensin (ANG) II content, while elevated ANG (1–7). Relative protein expressions of p-ERK/ERK and p-p38 MAPK/p38 MAPK inflammatory signals were downregulated upon xanthenone administration with tacrolimus. In addition, xanthenone reinforced antioxidant defense against tacrolimus by enhancing protein expression of the transcription factor Nrf2 with subsequently increased mRNA expressions of the antioxidants SOD3 and GCLC. SignificanceThese protective effects of xanthenone could be attributed to ANG II degradation to ANG (1–7) by ACE2 activation resulting in regulated inflammatory and oxidative responses in the kidney. Therefore, administration of xanthenone along with tacrolimus could be a promising therapeutic strategy to reduce the adverse effects and increase the tolerability to tacrolimus immunosuppressive therapy.

Nicotine exacerbates tacrolimus-induced renal injury by programmed cell death.

Background/AimsCigarette smoking is an important modifiable risk factor in kidney disease progression. However, the underlying mechanisms for this are lacking. This study aimed to assess whether nicotine (NIC), a major toxic component of cigarette smoking, would exacerbates tacrolimus (TAC)-induced renal injury.MethodsSprague-Dawley rats were treated daily with NIC, TAC, or both drugs for 4 weeks. The influence of NIC on TAC-caused renal injury was examined via renal function, histopathology, oxidative stress, mitochondria, endoplasmic reticulum (ER) stress, and programmed cell death (apoptosis and autophagy).ResultsBoth NIC and TAC significantly impaired renal function and histopathology, while combined NIC and TAC treatment aggravated these parameters beyond the effects of either alone. Increased oxidative stress, ER stress, mitochondrial dysfunction, proinflammatory and profibrotic cytokine expressions, and programmed cell death from either NIC or TAC were also aggravated by the two combined.ConclusionsOur observations suggest that NIC exacerbates chronic TAC nephrotoxicity, implying that smoking cessation may be beneficial for transplant smokers taking TAC.

Renoprotective Effects of Alpha-1 Antitrypsin against Tacrolimus-Induced Renal Injury.

The protective effects of alpha-1 antitrypsin (AAT) in tacrolimus (TAC)-induced renal injury was evaluated in a rat model. The TAC group rats were subcutaneously injected with 2 mg/kg TAC every day for four weeks. The TAC with AAT group was cotreated with daily subcutaneous injections of TAC and intraperitoneal injections of AAT (80 mg/kg) for four weeks. The effects of AAT on TAC-induced renal injury were evaluated using serum biochemistry, histopathology, and Western blotting. The TAC injection significantly increased renal interstitial fibrosis, inflammation, and apoptosis as compared to the control treatment. The histopathological examination showed that cotreatment of TAC and AAT attenuated interstitial fibrosis (collagen, fibronectin, and α-SMA staining), and α-SMA expression in Western blotting was also decreased. Immunohistochemical staining for inflammation (osteopontin and ED-1 staining) revealed improved interstitial inflammation in the TAC with AAT group compared to that in the TAC group. The TAC treatment increased renal apoptosis compared to the control treatment, based on the results of increased immunohistochemical staining of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), increased caspase-3 activity, and lower Bcl-2 to Bad expression ratio. However, AAT cotreatment significantly changed these markers and consequently showed decreased apoptosis. AAT protects against TAC-induced renal injury via antifibrotic, anti-inflammatory, and antiapoptotic effects.

L-Carnitine protects against tacrolimus-induced renal injury by attenuating programmed cell death via PI3K/AKT/PTEN signaling.

Reducing immunosuppressant-related complications using conventional drugs is an efficient therapeutic strategy. L-carnitine (LC) has been shown to protect against various types of renal injury. In this study, we investigated the renoprotective effects of LC in a rat model of chronic tacrolimus (TAC) nephropathy. SD rats were injected with TAC (1.5 mg · kg-1 · d-1, sc) for 4 weeks. Renoprotective effects of LC were assessed in terms of renal function, histopathology, oxidative stress, expression of inflammatory and fibrotic cytokines, programmed cell death (pyroptosis, apoptosis, and autophagy), mitochondrial function, and PI3K/AKT/PTEN signaling. Chronic TAC nephropathy was characterized by severe renal dysfunction and typical histological features of chronic nephropathy. At a molecular level, TAC markedly increased the expression of inflammatory and fibrotic cytokines in the kidney, induced oxidative stress, and led to mitochondrial dysfunction and programmed cell death through activation of PI3K/AKT and inhibition of PTEN. Coadministration of LC (200 mg · kg-1 · d-1, ip) caused a prominent improvement in renal function and ameliorated histological changes of kidneys in TAC-treated rats. Furthermore, LC exerted anti-inflammatory and antioxidant effects, prevented mitochondrial dysfunction, and modulated the expression of a series of apoptosis- and autophagy-controlling genes to promote cell survival. Human kidney proximal tubular epithelial cells (HK-2 cells) were treated with TAC (50 μg/mL) in vitro, which induced production of intracellular reactive oxygen species and expression of an array of genes controlling programmed cell death (pyroptosis, apoptosis, and autophagy) through interfering with PI3K/AKT/PTEN signaling. The harmful responses of HK-2 cells to TAC were significantly attenuated by cotreatment with LC and the PI3K inhibitor LY294002 (25 μM). In conclusion, LC treatment protects against chronic TAC nephropathy through interfering the PI3K/AKT/PTEN signaling.

Ginseng increases Klotho expression by FoxO3-mediated manganese superoxide dismutase in a mouse model of tacrolimus-induced renal injury.

The antioxidant function of Klotho is well-documented as a regulatory factor implicated in countering the aging process. This study investigated whether ginseng upregulates Klotho and its antiaging signaling in a setting of calcineurin inhibitor-induced oxidative stress. Although tacrolimus treatment reduced Klotho level in the serum and kidney, ginseng treatment was found to reverse the levels. Tacrolimus-induced oxidative stress was reduced by ginseng treatment, with functional and histological improvements. Effect of ginseng on Klotho-induced manganese superoxide dismutase signaling pathway during tacrolimus treatment in mice revealed that ginseng suppressed phosphatidylinositol 3-kinase/serine-threonine kinase Akt-mediated phosphorylation of forkhead box protein O3a and promoted the binding of forkhead box protein O3a to manganese superoxide dismutase promoter. In the mitochondria, ginseng reduced mitochondrial reactive oxygen species production, mitochondrial membrane potential, and oxygen consumption rate, whereas blocking phosphatidylinositol 3-kinase activity with LY294002 enhanced them. These findings together suggested that ginseng attenuated tacrolimus-induced oxidative stress via signaling between Klotho and the phosphatidylinositol 3-kinase/serine-threonine kinase Akt/forkhead box protein O3a-related antioxidant pathway.

Effect of Klotho on autophagy clearance in tacrolimus-induced renal injury.

Recently, we showed that tacrolimus-induced renal injury was closely associated with impairment of autophagy clearance, and Klotho deficiency aggravated tacrolimus-induced renal injury. In this study, we evaluated the effect of Klotho treatment on autophagy clearance in tacrolimus-induced renal injury. We evaluated the effect of Klotho on tacrolimus-induced renal injury in an experimental mouse model and in vitro by treatment with tacrolimus and/or recombinant mouse Klotho. In vivo and in vitro studies showed that tacrolimus treatment impaired lysosomal acidification and decreased cathepsin B activity, expression of lysosome-associated membrane protein 2, and expression of transcription factor EB (TFEB), a master regulator for lysosomal biogenesis. These results were improved by Klotho treatment. Moreover, addition of bafilomycin A1, an inhibitor of lysosomal function, abolished the protective effect of Klotho, indicating that the protective effect of Klotho was closely associated with lysosome function. Klotho induced nuclear translocation of TFEB through inhibition of phosphorylation of glycogen synthase kinase 3β (GSK3β) by confirming using CHIR99021, a GSK3β inhibitor. Collectively, our data suggest that Klotho improves autophagy clearance via activation of lysosomal function in tacrolimus-induced nephrotoxicity.-Lim, S. W., Shin, Y. J., Luo, K., Quan, Y., Ko, E. J., Chung, B. H., Yang, C. W. Effect of Klotho on autophagy clearance in tacrolimus-induced renal injury.

Shen-Kang protects against tacrolimus-induced renal injury.

Background/AimsEvidence suggests that Shen-Kang (SK), a traditional Chinese herbal medicine, protects against various types of renal injury. In this study, we evaluated whether SK treatment confers renoprotection in a rat model of chronic tacrolimus (TAC) nephropathy.MethodsRats were treated daily with TAC (1.5mg/kg, subcutaneously) and SK (450 mg/kg, intravenously) for 4 weeks. The effects of SK on TAC-induced renal injury were assessed by measuring renal function, urine albumin excretion, histopathology, inflammatory cell infiltration, expression of profibrotic (transforming growth factor β1 [TGF-β1] and TGF-β inducible gene-h3 [βig-h3]) and proinflammatory cytokines, oxidative stress, and apoptotic cell death.ResultsAdministration of SK preserved glomerular integrity (fractional mesangial area and Wilms tumor 1-positive glomeruli), attenuated tubulointerstitial fibrosis, and reduced the number of ectodermal dysplasia 1-positive cells, and this was paralleled by improved urine albumin excretion and renal dysfunction. At the molecular level, SK treatment suppressed expression of TGF-β1/Smad2/3, βig-h3, and proinflammatory cytokines. Oxidative stress and apoptotic cell death were significantly decreased with SK treatment, and apoptosis-related genes were regulated toward cell survival (active caspase-3 and the B-cell lymphoma-2/Bcl2-associated X [Bcl-2/Bax] ratio).ConclusionsSK protects against TAC-induced renal injury.

Inhibition of dipeptidyl peptidase IV protects tacrolimus-induced kidney injury

Accumulating evidence shows that a gut-released hormone, the glucagon-like peptide-1 (GLP-1), has not only a glucose-lowering effect but also a renoprotective effect against kidney injury. In this study, we investigated whether a dipeptidyl peptidase (DPP) IV inhibitor has a protective effect against tacrolimus-induced renal injury. Rats were treated with tacrolimus (1.5 mg/kg, subcutaneously) and the DPP IV inhibitor MK0626 (10 or 20 mg/kg, oral gavage) for 4 weeks. MK0626 treatment attenuated tacrolimus-induced renal dysfunction, tubulointerstitial fibrosis, and arteriolopathy. Moreover, these improvements were accompanied by a reduction in oxidative stress and apoptosis. MK0626 treatment increased the blood level of GLP-1 and the level of its receptor in tissue sections but did not alter the levels of other DPP IV substrates, such as neuropeptide Y and the stromal cell-derived factor-1. These data suggest that DPP IV inhibition has an important role in the renoprotection against tacrolimus-induced nephrotoxicity via antioxidative and antiapoptotic effects and preservation of the GLP-1 system.

Usefulness of a slow-release tacrolimus for a patient with tacrolimus-induced renal injury after hemopoietic stem cell transplantation

Usefulness of a slow-release tacrolimus for a patient with tacrolimus-induced renal injury after hemopoietic stem cell transplantation