Effects of sevoflurane on NF-кB and TNF-α expression in renal ischemia–reperfusion diabetic rats

The protective mechanism of sevoflurane in pulmonary arterial hypertension via downregulation of TRAF6

Pulmonary arterial hypertension (PAH) is an obstructive vasculopathy that, if not promptly treated, culminates in right heart failure. Therefore, pre-clinical studies are needed to support and optimize therapeutic approaches of PAH. Here, we explore a prospective function of sevoflurane in experimental PAH through regulating TRAF6. Monocrotaline (MCT)-induced PAH rats were subjected to sevoflurane inhalation and intratracheal instillation of lentivirus overexpressing TRAF6. Platelet-derived growth factor (PDGF)-treated pulmonary artery smooth muscle cells (PASMCs) were exposed to sevoflurane and genetically manipulated for TRAF6 overexpression. It was found that MCT and PDGF challenge upregulated the levels of TRAF6 in rat lung tissues and PASMCs, but sevoflurane treatment led to reduced TRAF6 expression. Sevoflurane inhalation in MCT-induced rats resulted in alleviative pulmonary vascular remodeling, mitigated right ventricular dysfunction and hypertrophy, improved mitochondrial function and dynamics, and inactivation of NF-κB pathway. In vitro studies confirmed that exposure to sevoflurane repressed PDGF-induced proliferation, migration, and phenotype switching of PASMCs, and suppressed mitochondrial dysfunction and NF-κB activation in PDGF-stimulated PASMCs. The beneficial impact of sevoflurane on pathological changes of lung and cell phenotype of PASMCs were reversed by overexpression of TRAF6. In summary, our study suggested the protective properties of sevoflurane in targeting PAH by downregulating TRAF6 expression, providing a novel avenue for the management of PAH.

Isoflurane preconditioning protects against renal ischemia/reperfusion injury in diabetes via activation of the Brg1/Nrf2/HO-1 signaling pathway

PURPOSE

To examine whether isoflurane preconditioning (IsoP) has a protective effect against renal ischemia/reperfusion injury (I/RI) in diabetic conditions and to further clarify the underlying mechanisms.

METHODS

Control and streptozotocin-induced diabetic rats were randomly assigned to five groups, as follows: normal sham, normal I/R, diabetic sham, diabetic I/R, and diabetic I/R + isoflurane. Renal I/RI was induced by clamping renal pedicle for 45 min followed by reperfusion for 24 h. IsoP was achieved by exposing the rats to 2% isoflurane for 30 min before vascular occlusion. Kidneys and blood were collected after reperfusion for further analysis. Renal histology, blood urea nitrogen, serum creatinine, oxidative stress, inflammatory cytokines, and renal cell apoptosis were assessed. Furthermore, the expression of brahma related gene 1 (Brg1), nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and nuclear factor-κB (NF-κB) were determined.

RESULTS

Compared with control, diabetic rats undergoing I/R presented more severe renal injury, oxidative stress, inflammatory reaction, and apoptosis with the impairment of Brg1/Nrf2/HO-1 signaling. All these alterations were significantly attenuated by pretreatment with isoflurane.

CONCLUSIONS

These findings suggest that isoflurane could alleviate renal I/RI in diabetes, possibly through improving Brg1/Nrf2/HO-1 signaling.

Thiadiazine-thione derivatives ameliorate STZ-induced diabetic neuropathy by regulating insulin and neuroinflammatory signaling

Diabetes Mellitus is accompanied by chronic hyperglycemia, inflammation, and related molecular processes, which leads to diabetic neuropathy. In this work, we tested Thiadiazine-thione (TDT) synthetic derivatives TDT1 and TDT2 against streptozotocin (STZ)-induced diabetic neuropathy. Sprague Dawley's rats, SH-SY5Y neuronal and BV2 microglial cells were employed in this work, followed by behavioral, biochemical, and morphological studies utilizing RT-qPCR, ELISA, Immunoblotting, immunohistochemistry, Immunofluorescence, and in silico analyses. TDT1 and TDT2 abolished STZ-induced allodynia and hyperalgesia. Next, we examined IRS1/PI3K/AKT signaling to assess TDT1 and TDT2's impact on diabetic neuropathy. STZ downregulated IRS1, PI3K, AKT mRNA and protein expression in rat spinal cord and SH-SY5Y neuronal cells. TDT1 and TDT2 improved IRS1, PI3k, and AKT mRNA and protein expression. STZ elevated GSK3β mRNA and protein expression in vivo and in vitro, whereas TDT1 and TDT2 mitigated it. STZ increased the expression of inflammatory mediators such as p-NF-κB, TNF-α, and COX-2 in rat spinal cord lysates. TDT1 and TDT2 co-treatment with STZ decreased inflammatory cytokine expression by ameliorating astrocytosis (revealed by increased GFAP) and microgliosis (indicated by increased Iba1). TDT1 and TDT2 reduced STZ-induced JNK, Iba1, and COX-2 upregulation in BV2 microglial cells validating our in vivo findings. In silico molecular docking and MD simulations analyses suggested that TDT1 and TDT2 have IRS binding affinity, however, both compounds had an identical binding affinity, but distinct interaction pattern with IRS protein residues. Overall, these findings demonstrate that TDT derivatives mitigated STZ-induced neuropathy through modulating the insulin and inflammatory signaling pathways.

The Effect of Curcumin on Renal Ischemia/Reperfusion Injury in Diabetic Rats

Chronic kidney disease (CKD) and acute kidney injury (AKI) are global health problems that affect over 850 million people, twice the number of diabetic individuals around the world. Diabetes mellitus (DM) is known to increase the susceptibility to AKI. Plants and foods, such as curcumin, are traditionally used as treatments for various diseases due to its wide range of bioactive compounds that exert antioxidative, anti-inflammatory, antimicrobial and anticancer properties. The aim of this study is to evaluate the effect of curcumin in diabetic rats with AKI. Adult male Wistar rats, weighing between 250 and 290 g, were randomized into four groups: Citrate (citrate buffer, i.v., single dose, on Day 1 of the protocol); DM (streptozotocin (STZ), 65 mg/k, single dose, i.v., on Day 1); DM + I/R (DM rats that, on Day 26, had the renal pedicle clamped for 30 min on both sides); DM + I/R + Curcumin (DM + I/R rats submitted to curcumin treatment). Results showed that IR worsened renal function and oxidative stress in DM rats, but the DM + IR + Curcumin group showed an increase in inulin clearance and a decrease in serum creatinine and in NGAL, in addition to an improvement in renal hemodynamics. These effects were accompanied by a reduction in oxidative and nitrosative metabolites and an increase in the thiol antioxidant reserve when curcumin was administered to the DM + IR group.

Downregulation of TREM2/NF-кB signaling may damage the blood-brain barrier and aggravate neuronal apoptosis in experimental rats with surgically injured brain

Surgical brain injury (SBI) is unavoidable in neurosurgery, and could aggravate secondary brain injury. Post-brain injury, multiple inflammatory factors are released, resulting in neuroinflammation and cell apoptosis, with subsequent brain edema and nerve function injury. TREM2, an immune protein mainly expressed in microglia, is an important link for nerve cells to participate in the inflammatory response. TREM2 and nuclear factor кB (NF-кB) are indeed closely associated with the release of inflammatory cytokines following brain injury. This work aimed to determine the inflammatory function of TREM2 in SBI, and to investigate whether TREM2 regulates interleukin-1 beta (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) release through the NF-кB p65 signaling pathway. We established a rat model of SBI, and performed Western blotting (WB), immunofluorescence (IF) and enzyme-linked immunosorbent assay (ELISA) for further analysis. Next, brain edema and neurological score analyses were performed. Finally, whether TREM2 regulating NF-кB p65 signaling affects blood-brain barrier (BBB) permeability and nerve cell apoptosis was examined. We found that post-SBI, TREM2 was upregulated, and inflammation and brain injury were aggravated. After TREM2 downregulation, NF-кB p65 production, inflammation and brain injury were enhanced, suggesting that TREM2 may play a protective role by inhibiting NF-кB p65 production after SBI. Overall, these findings suggest that TREM2 in SBI may have protective effects on postoperative nerve and BBB damage, possibly in part via the NF-κB p65 pathway.

Anesthetics mediated the immunomodulatory effects via regulation of TLR signaling

Anesthetics have been widely used in surgery and found to suppress inflammatory injury and affect the outcomes of the surgery and diseases. In contrast, anesthetics are also found to induce neuronal injury and inflammation. However, the immune-modulation mechanism of anesthetics is still not clear. Recent studies have shown that the immune-modulation of anesthetics is associated with the regulation of toll-like receptor (TLR)-mediated signaling. Moreover, the regulation of anesthetics in TLR signaling is related to modulations of non-coding RNAs (nc RNAs). Consistently, nc RNAs are mainly divided into micro RNAs (miRs) and long non-coding RNAs (lnc RNAs), which have been found to exert regulatory effects on the immune system. In this review, we summarize the immunomodulatory functions of the widely used anesthetic agents, which are associated with regulation of TLR signaling. In addition, we also focus on the roles of nc RNAs induced by anesthetics in regulations of TLR signaling.

Effects of stem cell-derived exosomes on neuronal apoptosis and inflammatory cytokines in rats with cerebral ischemia-reperfusion injury via PI3K/AKT pathway-mediated mitochondrial apoptosis

OBJECTIVE

This study aimed to investigate the effects of stem cell-derived exosomes (SC-Exos) on learning, memory, and neuronal apoptosis in rats with cerebral ischemia-reperfusion injury and to determine whether SC-Exos exert their effects via phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) pathway-mediated mitochondrial pathways of apoptosis.

MATERIALS AND METHODS

Eighty rats were randomly allocated to control, model, SC-Exos, and PI3K inhibitor groups. A model of focal cerebral ischemia-reperfusion was established using the improved Longa method. Expression of interleukin-1α (IL-1α), interleukin-2 (IL-2), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were compared in the brains and serum of each group. The expressions of Bcl-2, Bax, cleaved-caspase-3, cleaved-caspase-9, cytochrome C (CytC), PI3K, and AKT-related genes and proteins were evaluated by real-time quantitative polymerase chain reaction and western blotting.

RESULTS

The SC-Exos-group exhibited more novel entries, less latency for the novel arm, and fewer entries into the starting arm and other arms than the model group (p<.05). Lower expression of the inflammatory cytokines IL-1α, IL-2, and TNF-α and higher expression of IFN-γ were observed in the SC-Exos group than in the model group. TdT-mediated dUTP nick end labeling (TUNEL) assay showed that lower neural cell apoptosis rate and expression of Bax, cleaved-caspase-3, cleaved-caspase-9, CytC, PI3K, and AKT mRNA and proteins and higher expression of Bcl-2 mRNA and protein were observed in the SC-Exos group than in the model group (p<.05).

CONCLUSIONS

SC-Exos can significantly ameliorate brain injury caused by cerebral ischemia-reperfusion. The mechanism may be a novel therapeutic target for ischemia-reperfusion injury.

Sevoflurane preconditioning activates HGF/Met-mediated autophagy to attenuate hepatic ischemia-reperfusion injury in mice

Sevoflurane (SEV) preconditioning plays a protective effect against liver ischemia reperfusion (IR) injury, while the role of autophagy in SEV-mediated hepatoprotection and the precise mechanism is unclear. In the current study, mice were pretreated with SEV or autophagy inhibitor before liver IR injury. In vitro, primary rat hepatocytes were pretreated with SEV and then exposed to hypoxia/reoxygenation (H/R). Liver function was measured by biochemical and histopathological examinations, and markers associated with inflammation, oxidation, apoptosis and autophagy were subsequently measured. We found that SEV preconditioning dramatically reduced hepatic damage, alleviated cell inflammatory response, oxidative stress and apoptosis in mice suffering hepatic IR injury, whereas these protective effects were abolished by the autophagy inhibitor 3-MA. In addition, pretreatment with SEV markedly activated HGF/Met signaling pathway regulation. Besides, pretreatment with an hepatocyte growth factor (HGF) inhibitor or knocking down HGF expression significantly downregulated phosphorylated met (p-met) and autophagy levels, and abolished the protective effects of SEV against hepatic IR or hepatocyte H/R injury. Conversely, HGF overexpression efficiently increased the p-met and autophagy levels and strengthened the protective effects of SEV. These results indicated that sevoflurane preconditioning ameliorates hepatic IR injury by activating HGF/Met-mediated autophagy.

NLRP3 inflammasome mediated pyroptosis is involved in cadmium exposure-induced neuroinflammation through the IL-1β/IkB-α-NF-κB-NLRP3 feedback loop in swine

Cadmium (Cd) chloride, as widely distributed toxic environmental pollutants by using in industry, severely imperils animal and human health. Pyroptosis is a Cas1-dependent pro-inflammatory programmed cell death and involves in various types of diseases. Nevertheless, the mechanism of pyroptosis and Cd-induced neurotoxicity remains obscure. To investigate the specific molecular mechanisms of Cd-induced neurotoxicity, 10 weaned piglets were randomly divided into 2 groups treated with 0 and 20 mg/kg CdCl₂ in the diet for 40 days. The levels of pyroptosis, mitochondrial and inflammation-related genes were validated by qRT-PCR and WB in vivo. Our results revealed that Cd caused cerebral histopathology lesions, inducing cerebral pyroptosis and the mass generation of inflammatory cytokines, as indicated by the increased NLRP3 inflammasome activation (NLRP3, Cas1 and ASC) and the upregulation of inflammation factors IL-2, IL-6, IL-7 and inhibition of IL-10. Subsequently, further research indicated that Cd triggered pyroptosis via activating the TRAF6-IkB-α-NF-κB pathway, which interfered with the phosphorylation and ubiquitination of IkB-α. Furthermore, Cd caused mitochondrial dysfunction and fragmentation by inhibiting the AMPK-PGC-1α-NRF1/2 signaling pathway and reduced the expression of mitochondrial-related regulatory factors OPA1, TFAM and mtDNA, resulting in the increase of NLRP3 inflammasome. Besides, we found eight hub genes (IKK, IKB-α, NLRP3, TRAF6, NF-κB, AMPK, TNFα and PGC-1α), mainly related to the interaction between the NF-κB pathway and NLRP3 inflammasome. Overall, these results demonstrated that Cd could promote the IL-1β/IkB-α-NF-κB-NLRP3 inflammasome activation positive feedback loop to result in neuroinflammation in swine, which provided new insights in understanding Cd-induced toxicity.

Ameliorating Effect of Pentadecapeptide Derived from Cyclina sinensis on Cyclophosphamide-Induced Nephrotoxicity

Cyclophosphamide (CTX) is a widely used anticancer drug with severe nephrotoxicity. The pentadecapeptide (RVAPEEHPVEGRYLV) from Cyclina sinensis (SCSP) has been shown to affect immunity and to protect the liver. Hence, the purpose of this study was to investigate the ameliorating effect of SCSP on CTX-induced nephrotoxicity in mice. We injected male ICR mice with CTX (80 mg/kg·day) and measured the nephrotoxicity indices, levels of antioxidant enzymes, malondialdehyde (MDA), inflammatory factors, as well as the major proteins of the NF-κB and apoptotic pathways. Cyclophosphamide induced kidney injury; the levels of kidney-injury indicators and cytokines recovered remarkably in mice after receiving SCSP. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) increased, while there was a significant decrease in MDA levels. The kidney tissue damage induced by CTX was also repaired to a certain extent. In addition, SCSP significantly inhibited inflammatory factors and apoptosis by regulating the NF-κB and apoptotic pathways. Our study shows that SCSP has the potential to ameliorate CTX-induced nephrotoxicity and may be used as a therapeutic adjuvant to ameliorate CTX-induced nephrotoxicity.

Resveratrol inhibits TNF-α-induced inflammation to protect against renal ischemia/reperfusion injury in diabetic rats

Purpose

To examine effects of resveratrol on renal ischemia/ reperfusion injury (I/R) in a streptozotocin (STZ)-induced diabetic rat model.

Methods

Twenty-four male Sprague Dawley rats were treated with STZ injection for the development of diabetes, and divided into the following groups: Sham group, I/R group and Resveratrol group (n=8). Resveratrol (RSV) was administered at a dose of 10 mg.kg-1.d-1 fourteen days prior to suffering from I/R. Renal function, histology, SOD, MDA, TUNEL assay and expression of TNF-α, IL-1β, NF-κB-P65, COX-2 and Caspase3, Bcl2 and Bax were analyzed.

Results

Administration of RSV significantly reduced the serum levels of renal dysfunction and injury markers, including creatinine, blood urea nitrogen and MDA; in the other hand, it significantly increased the serum levels of SOD. The protective effect of RSV was also reflected on histologic evaluation. RSV reduced the number of apoptotic cells as determined by TUNEL assay. RSV significantly reduced the protein expression of TNF-α, IL-1β, NF-κB-P65, COX-2 and Caspase3, and Bax. Meanwhile, RSV significantly increased the protein expression of Bcl2.

Conclusion

RSV attenuated I/R-induced renal injury in diabetic rats through the modulation of oxidative stress and TNF-α-stimulated inflammation.

Diabetes aggravates renal ischemia and reperfusion injury in rats by exacerbating oxidative stress, inflammation, and apoptosis

Diabetic patients are more susceptible to renal ischemia/reperfusion (I/R) injury (RI/RI) and have a poor prognosis, but the underlying mechanism remains unclear. The present study aimed to examine whether diabetes could worsen acute kidney injury induced by I/R in rats and clarify its mechanism. Control and streptozotocin-induced diabetic rats were subjected to 45 min renal pedicle occlusion followed by 24 h reperfusion. Tert-butylhydroquinone (TBHQ, 16.7 mg/kg) was administrated intraperitoneally 3 times at intervals of 8 h before ischemia. Serum and kidneys were harvested after reperfusion to evaluate renal function and histological injury. Enzyme-linked immunosorbent assays were used to test pro-inflammatory cytokines. Terminal deoxynucleotidyl-transferase-mediated dUTP nick-end labeling assays were used to detect apoptotic cells, and western blotting was performed to determine the expression of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), and cleaved caspase-3, as well as oxidative stress and inflammation-related proteins, such as nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Toll-like receptor 4 (TLR4), and nuclear factor-κB (NF-κB). Compared with control animals, diabetic rats undergoing I/R exhibited more severe tubular damage and renal dysfunction. Diabetes exacerbated oxidative stress, the inflammatory response, and apoptosis after renal I/R by enhancing TLR4/NF-κB signaling and blocking the Nrf2/HO-1 pathway. RI/RI in diabetic rats was attenuated by pretreatment with TBHQ (a Nrf2 agonist), which exerted anti-inflammatory and anti-apoptotic properties by inhibiting NF-κB signaling. These findings indicate that hyperglycemia exacerbates RI/RI by intensifying oxidative stress, inflammation, and apoptosis. Antioxidant pretreatment may alleviate RI/RI in diabetic patients.

Pioglitazone Attenuates Reoxygenation Injury in Renal Tubular NRK-52E Cells Exposed to High Glucose via Inhibiting Oxidative Stress and Endoplasmic Reticulum Stress

Renal ischemia-reperfusion injury is a major cause of acute kidney injury. In the present study, we investigated the effects of pioglitazone on hypoxia/reoxygenation (H/R) injury in rat renal tubular epithelial cells (RTECs) under normal- (NG) or high-glucose (HG) culture conditions via evaluating oxidative stress and endoplasmic reticulum stress (ERS). The RTECs (NRK-52E cells) were divided into six groups as follows: NG group, HG group, NG + H/R group, HG + H/R group, NG + Pio + H/R group, and HG + Pio + H/R group, among which cells in H/R groups were subjected to 4 h of hypoxia followed by 12 h of reoxygenation. After that, the cells were evaluated using the Cell Counting Kit-8 assay for the determination of their viability and flow cytometry assay for the detection of apoptosis. The levels of superoxide dismutase (SOD), glutathione reductase (GSH), catalase (CAT), and malondialdehyde (MDA) were determined via colorimetric chemical assays. In addition, the expression of ERS-associated proteins, i.e. ATF4, ATF6, GRP78, and CHOP, was determined via western blotting. A HG environment could reduce the viability and increase the apoptotic rate of NRK-52E cells with increased MDA levels and decreased SOD, CAT, and GSH levels, and upregulate the expression of ERS-associated proteins, i.e. ATF4, ATF6, and GRP78. H/R injury could further aggravate changes in the above indicators, but pioglitazone could significantly reverse such changes and alleviate cell injury. Thus, Pioglitazone exhibits a cytoprotective effect on RTECs against H/R injury under NG or HG culture conditions by inhibiting oxidative stress and ERS.

Inhibition of the SIRT1 signaling pathway exacerbates endoplasmic reticulum stress induced by renal ischemia/reperfusion injury in type 1 diabetic rats

The aim of the present study was to investigate whether the diabetic kidney is more susceptible to ischemia/reperfusion (I/R) injury, and identify the potential mechanisms involved. An animal model of type 1 diabetes was created by treating rats with streptozotocin (STZ). This model was then used, along with healthy controls, to investigate the effect of diabetes mellitus (DM) on renal I/R injury. After 45 min of ischemia and 24 h of reperfusion, kidney and serum samples were acquired and used to evaluate function and histopathological injury in the kidneys. Western blotting was also used to determine the expression levels of key proteins. Rats experiencing renal I/R exhibited significant characteristics of renal dysfunction, reduced levels of Sirtuin 1 (SIRT1) protein (a key signaling protein in the kidneys), increased endoplasmic reticulum stress (ERS) and pyroptosis. Furthermore, diabetic rats exhibited further reductions in the levels of SIRT1 in response to renal I/R injury and an increase in the levels of ERS. These effects were all alleviated by the administration of a SIRT1 agonist. The present analysis revealed that the SIRT1-mediated activation of ER stress and pyroptosis played a pivotal role in diabetic rats subjected to renal I/R injury. Downregulation of the SIRT1 signaling pathway were exacerbated in response to renal I/R injury-induced acute kidney injury (AKI). The present data indicated that DM enhanced ER stress and increased pyroptosis by downregulating the SIRT1 signaling pathway.

Chrysin protects against renal ischemia reperfusion induced tubular cell apoptosis and inflammation in mice

Renal ischemia reperfusion (IR) is a major cause of acute kidney injury with no effective treatment. Chrysin is an anti-inflammatory, anti-oxidant and anti-cancer agent. However, the effect of chrysin on renal IR injury remains unknown. In this study, sham operation, IR and IR+chrysin group mice were treated with or without renal IR injury. For renal IR, bilateral renal pedicles were clamped for 30 min and then released for 48 h of reperfusion. Blood and kidney samples were collected for analysis. Results demonstrated that chrysin pretreatment remarkably decreased the levels of serum creatinine and blood urea nitrogen and attenuated morphological abnormalities in renal IR injury. Consistently, tubular cell apoptosis and inflammation were more attenuated in the chrysin pretreatment group compared with the IR group. Chrysin pretreatment decreased the expression of Bax and cleaved caspase-3 and increased the expression of Bcl-2 in renal IR injury. Furthermore, chrysin administration decreased the mRNA and protein levels of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. Furthermore, the IκBα/nuclear factor-κB signaling pathway was more suppressed in the chrysin pretreatment group compared with the IR group. In conclusion, chrysin protects against tubular cell apoptosis and inflammation in renal IR injury.

Melatonin attenuates acute kidney ischemia/reperfusion injury in diabetic rats by activation of the SIRT1/Nrf2/HO-1 signaling pathway

Background and aims: Diabetic kidney is more sensitive to ischemia/reperfusion (I/R) injury, which is associated with increased oxidative stress and impaired nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling. Melatonin, a hormone that is secreted with the rhythm of the light/dark cycle, has antioxidative effects in reducing acute kidney injury (AKI). However, the molecular mechanism of melatonin protection against kidney I/R injury in the state of diabetes is still unknown. In the present study, we hypothesized that melatonin attenuates renal I/R injury in diabetes by activating silent information regulator 2 associated protein 1 (SIRT1) expression and Nrf2/HO-1 signaling. Methods: Control or streptozotocin (STZ)-induced Type 1 diabetic rats were treated with or without melatonin for 4 weeks. Renal I/R injury was achieved by clamping both left and right renal pedicles for 30 min followed by reperfusion for 48 h. Results: Diabetic rats that were treated with melatonin undergoing I/R injury prevented renal injury from I/R, in aspects of the histopathological score, cell apoptosis, and oxidative stress in kidney, accompanied with decreased expressions of SIRT1, Nrf2, and HO-1 as compared with those in control rats. All these alterations were attenuated or prevented by melatonin treatment; but these beneficial effects of melatonin were abolished by selective inhibition of SIRT1 with EX527. Conclusion: These findings suggest melatonin could attenuate renal I/R injury in diabetes, possibly through improving SIRT1/Nrf2/HO-1 signaling.