Vildagliptin Attenuates Hepatic Ischemia/Reperfusion Injury via the TLR4/NF-κB Signaling Pathway

TLR4 inhibitors through inhibiting (MYD88-TRIF) pathway, protect against experimentally-induced intestinal (I/R) injury

Intestinal ischemia/reperfusion (I/R) injury is a serious condition that causes intestinal dysfunction and can be fatal. Previous research has shown that toll-like receptor 4 (TLR4) inhibitors have a protective effect against this injury. This study aimed to investigate the protective effects of TLR4 inhibitors, specifically cyclobenzaprine, ketotifen, amitriptyline, and naltrexone, in rats with intestinal (I/R) injury. Albino rats were divided into seven groups: vehicle control, sham-operated, I/R injury, I/R-cyclobenzaprine (10 mg/kg body weight), I/R-ketotifen (1 mg/kg body weight), I/R-amitriptyline (10 mg/kg body weight), and I/R-naltrexone (4 mg/kg body weight) groups. Anesthetized rats (urethane 1.8 g/kg) underwent 30 min of intestinal ischemia by occluding the superior mesenteric artery (SMA), followed by 2 h of reperfusion. Intestinal tissue samples were collected to measure various parameters, including malondialdehyde (MDA), nitric oxide synthase (NO), myeloperoxidase (MPO), superoxide dismutase (SOD), TLR4, intercellular adhesion molecule-1 (ICAM-1), nuclear factor kappa bp65 (NF-ĸBP65), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), macrophages CD68, myeloid differentiation factor 88 (MYD88), and toll interleukin receptor-domain-containing adaptor-inducing interferon β (TRIF). The use of TLR4 inhibitors significantly reduced MDA, MPO, and NO levels, while increasing SOD activity. Furthermore, it significantly decreased TLR4, ICAM-1, TNF-α, MCP-1, MYD88, and TRIF levels. These drugs also showed partial restoration of normal cellular structure with reduced inflammation. Additionally, there was a decrease in NF-ĸBP65 and macrophages CD68 staining compared to rats in the I/R groups. This study focuses on how TLR4 inhibitors enhance intestinal function and protect against intestinal (I/R) injury by influencing macrophages CD86 through (MYD88-TRIF) pathway, as well as their effects on oxidation and inflammation.

Targeting NF-κB in Hepatic Ischemia-Reperfusion Alleviation: from Signaling Networks to Therapeutic Targeting

Hepatic ischemia-reperfusion injury (HIRI) is a major complication of liver trauma, resection, and transplantation that can lead to liver dysfunction and failure. Scholars have proposed a variety of liver protection methods aimed at reducing ischemia-reperfusion damage, but there is still a lack of effective treatment methods, which urgently needs to find new effective treatment methods for patients. Many studies have reported that signaling pathway plays a key role in HIRI pathological process and liver function recovery mechanism, among which nuclear transfer factor-κB (NF-κB) signaling pathway is one of the signal transduction closely related to disease. NF-κB pathway is closely related to HIRI pathologic process, and inhibition of this pathway can delay oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction. In addition, NF-κB can also interact with PI3K/Akt, MAPK, and Nrf2 signaling pathways to participate in HIRI regulation. Based on the role of NF-κB pathway in HIRI, it may be a potential target pathway for HIRI. This review emphasizes the role of inhibiting the NF-κB signaling pathway in oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction in HIRI, as well as the effects of related drugs or inhibitors targeting NF-κB on HIRI. The objective of this review is to elucidate the role and mechanism of NF-κB pathway in HIRI, emphasize the important role of NF-κB pathway in the prevention and treatment of HIRI, and provide a theoretical basis for the target NF-κB pathway as a therapy for HIRI.

Crocetin preconditioning attenuates ischemia reperfusion-induced hepatic injury by disrupting Keap1/Nrf2 interaction and activating Nrf2/HO-1 pathway

BACKGROUND

Ischemia reperfusion (I/R) injury is a frequent occurrence during liver transplantation surgery, resulting from the temporary cessation of blood flow and subsequent restoration of blood flow. Serious I/R injury is a significant factor causing transplant failure. Hepatic I/R process is characterized by excessive inflammation, oxidation, and apoptosis. Crocetin (Crt) is a natural compound exhibiting beneficial roles in various I/R-induced organ damages. However, Crt's potential role in hepatic I/R remains unexplored.

OBJECTIVE AND METHODS

In order to reveal the impact of Crt on hepatic I/R and the associated signaling pathway, we utilized a syngeneic orthotopic liver transplantation rat model to induce hepatic I/R injury.

RESULTS

Pretreatment with Crt significantly mitigated hepatic I/R injury. This was evident by decreased activities of serum ALT, AST and LDH, indicating improved liver function. Crt treatment also alleviated oxidative stress, as demonstrated by decreased serum MDA content and elevated serum SOD and GSH-Px activities. Furthermore, Crt suppressed inflammatory responses by downregulating both the serum and liver IL-1β, IL-6 and TNF-α while upregulating IL-10 expression. Additionally, Crt reduced apoptosis by decreasing pro-apoptotic Bax, cleaved caspase-3 and cleaved caspase-9, while increasing anti-apoptotic Bcl2 expression. Notably, these protective effects of Crt were dose-dependent. Moreover, our data indicates that Crt plays protective functions during hepatic I/R via disrupting Keap1/Nrf2 interaction and activating Nrf2/HO-1 signaling. This was further supported by observations of alleviated hepatic histopathological changes in I/R rats treated with Crt.

CONCLUSIONS

Crt shows potential as a therapeutic agent for preventing hepatic I/R injury during clinical liver transplantation.

Inflammatory setting, therapeutic strategies targeting some pro-inflammatory cytokines and pathways in mitigating ischemia/reperfusion-induced hepatic injury: a comprehensive review

Ischemia/reperfusion injury (IRI) is a key determining agent in the pathophysiology of clinical organ dysfunction. It is characterized by an aseptic local inflammatory reaction due to a decrease in blood supply, hence deprivation of dependent oxygen and nutrients. In instances of liver transplantation, this injury may have irreversible implications, resulting in eventual organ rejection. The deterioration associated with IRI is affected by the hepatic health status and various factors such as alterations in metabolism, oxidative stress, and pro-inflammatory cytokines. The primary cause of inflammation is the initial immune response of pro-inflammatory cytokines, while Kupffer cells (KFCs) and neutrophil-produced chemokines also play a significant role. Upon reperfusion, the activation of inflammatory responses can elicit further cellular damage and organ dysfunction. This review discusses the interplay between chemokines, pro-inflammatory cytokines, and other inflammatory mediators that contribute to the damage to hepatocytes and liver failure in rats following IR. Furthermore, it delves into the impact of anti-inflammatory therapies in safeguarding against liver failure and hepatocellular damage in rats following IR. This review investigates the correlation between cytokine factors and liver dysfunction via examining databases, such as PubMed, Google Scholar, Science Direct, Egyptian Knowledge Bank (EKB), and Research Gate.

DPP-4 exacerbates LPS-induced endothelial cells inflammation via integrin-α5β1/FAK/AKT signaling

Endothelial dysfunction plays a pivotal role in the pathogenesis of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Dipeptidyl peptidase IV (DPP-4), a cell surface glycoprotein, has been implicated in endothelial inflammation and barrier dysfunction. In this study, the role of DPP-4 on lipopolysaccharide (LPS)-induced pulmonary microvascular endothelial cells (HPMECs) dysfunction and the underlying mechanism were investigated by siRNA-mediated knockdown of DPP-4. Our results indicated that LPS (1 μg/ml) challenge resulted in either the production and releasing of DPP-4, as well as the secretion of IL-6 and IL-8 in HPMECs. DPP-4 knockdown inhibited chemokine releasing and monolayer hyper-permeability in LPS challenged HPMECs. When cocultured with human polymorphonuclear neutrophils (PMNs), DPP4 knockdown suppressed LPS-induced neutrophil-endothelial adhesion, PMN chemotaxis and trans-endothelial migration. Western blotting showed that DPP-4 knockdown attenuated LPS-induced activation of TLR4/NF-κB pathway. Immunoprecipitation and liquid chromatography-tandem mass spectrometry revealed that DPP-4 mediated LPS-induced endothelial inflammation by interacting with integrin-α5β1. Moreover, exogenous soluble DPP-4 treatment sufficiently activated integrin-α5β1 downstream FAK/AKT/NF-κB signaling, thereafter inducing ICAM-1 upregulation in HPMECs. Collectively, our results suggest that endothelia synthesis and release DPP-4 under the stress of endotoxin, which interact with integrin-α5β1 complex in an autocrine or paracrine manner to exacerbate endothelial inflammation and enhance endothelial cell permeability. Therefore, blocking DDP-4 could be a potential therapeutic strategy to prevent endothelial dysfunction in ALI/ARDS.

Bilobalide attenuates lipopolysaccharide‑induced HepG2 cell injury by inhibiting TLR4‑NF‑κB signaling via the PI3K/Akt pathway

Inflammation is involved in the pathological process underlying a number of liver diseases. Bilobalide (BB) is a natural compound from Ginkgo biloba leaves that was recently demonstrated to exert hepatoprotective effects by inhibiting oxidative stress in the liver cancer cell line HepG2. The anti-inflammatory activity of BB has been reported in recent studies. The major objective of the present study was to investigate whether BB could attenuate inflammation-associated cell damage. HepG2 cells were cultured with lipopolysaccharide (LPS) and BB, and cell damage was evaluated by measuring cell viability using MTT assay. The activity of the NF-κB signaling pathway was assessed by measuring the levels of IκBα, NF-κB p65, phosphorylated (p)-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines IL-1β, IL-6 and TNF-α. A toll-like receptor (TLR)4 inhibitor (CLI-095) was used to detect the involvement of TLR4 in cell injury caused by LPS. In addition, the PI3K/Akt inhibitor LY294002 was applied to explore the involvement of the PI3K/Akt axis in mediating the effects of BB. The results demonstrated that LPS induced HepG2 cell injury. LPS also elevated the levels of p-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines. However, CLI-095 significantly attenuated the LPS-induced cell damage and inhibited the activation of NF-κB signaling. BB also dose-dependently attenuated the LPS-induced cell damage, activation of NF-κB signaling and TLR4 overexpression. Furthermore, it was observed that LY294002 diminished the cytoprotective effects of BB on cell injury, TLR4 expression and NF-κB activation. These findings indicated that BB could attenuate LPS-induced inflammatory injury to HepG2 cells by regulating TLR4-NF-κB signaling.

Chlorogenic Acid Alleviates Hepatic Ischemia-Reperfusion Injury by Inhibiting Oxidative Stress, Inflammation, and Mitochondria-Mediated Apoptosis In Vivo and In Vitro

Hepatic ischemia-reperfusion injury (HIRI) is the main reason for organ failure following liver surgery; however, its underlying causes are complex, and include oxidative stress, sterile inflammatory, and mitochondrial damage. Unfortunately, treatments for HIRI are based on supportive therapy, and no specific drugs or methods are currently available. Chlorogenic acid (CGA) is a dietary polyphenol with a wide range of pharmacological effects and it has a protective effect on HIRI; however, its specific mechanism remains unclear. In this study, we investigated that CGA pretreatment exerts protective effects against HIRI and the potential underlying mechanisms. We found that CGA pretreatment reduced ALT, AST, MDA, TNF-α, and IL-1β levels following HIRI, improved SOD and GSH levels, and alleviated pathological liver tissue damage, with the highest CGA dose (100 mg/kg.d) exerted the strongest effect. In addition, we showed that CGA pretreatment significantly decreased the levels of reactive oxygen species following HIRI, inhibited HMGB1 release by decreasing IRF-1 expression, inhibited the expression of HMGB1, TLR-4, MyD88, P-IκB-α, NF-κB P65, and P-P65, and promoted IκB-α degradation. Thus, CGA appears to inhibit oxidative stress and inflammatory responses during HIRI. Furthermore, we found that CGA pretreatment reduced hepatocyte apoptosis following HIRI, alleviated mitochondrial damage, promoted BCL-2 expression, inhibited Bax upregulation, and inhibited cytochrome C release to prevent caspase activation, thereby reducing the expression of the caspase-independent pathway components, ENDOG and AIF. Together, our findings suggest that CGA can protect against HIRI by inhibiting oxidative stress, the HMGB1/TLR-4/NF-κB signaling pathway-mediated inflammatory responses, and mitochondria-mediated apoptosis. Thus, CGA appears to be a promising therapeutic approach for treating HIRI.

Folium Ginkgo extract and tetramethylpyrazine sodium chloride injection (Xingxiong injection) protects against focal cerebral ischaemia/reperfusion injury via activating the Akt/Nrf2 pathway and inhibiting NLRP3 inflammasome activation

CONTEXT

Folium Ginkgo extract and tetramethylpyrazine sodium chloride injection (Xingxiong injection) is a compound preparation commonly used for treating cerebral ischaemia/reperfusion injury in ischaemic stroke in China. However, its potential mechanisms on ischaemic stroke remain unknown.

OBJECTIVE

This study explores the potential mechanisms of Xingxiong injection in vivo or in vitro.

MATERIALS AND METHODS

Sprague-Dawley (SD) rats were randomly assigned to five groups: the sham (normal saline), the model (normal saline) and the Xingxiong injection groups (12.5, 25 or 50 mL/kg). The rats were subjected to 2 h of middle cerebral artery occlusion (MCAO) followed by reperfusion for 14 d. Xingxiong injection was administered via intraperitoneal (i.p.) injection immediately after ischaemia induction for 14 d. Afterwards, rats were sacrificed at 14 d induced by administration of Xingxiong injection.

RESULTS

Xingxiong injection significantly reduces infarct volume (23%) and neurological deficit scores (93%) compared with the MCAO/R group. Additionally, Xingxiong injection inhibits the loss in mitochondrial membrane potential (43%) and reduces caspase-3 level (44%), decreases NOX (41%), protein carbonyl (29%), 4-HNE (40%) and 8-OhdG (41%) levels, inhibits the expression of inflammatory factors, such as TNF-α (26%), IL-1β (34%), IL-6 (39%), MCP-1 (36%), CD11a (41%) and ICAM-1 (43%). Moreover, Xingxiong injection can increase p-Akt/Akt (35%) and Nrf2 (47%) protein expression and inhibit NLRP3 (42%) protein expression.

CONCLUSIONS

Xingxiong injection prevents cerebral ischaemia/reperfusion injury via activating the Akt/Nrf2 pathway and inhibiting NLRP3 inflammasome. These findings provide experimental evidence for clinical use of drugs in the treatment of ischaemic stroke.

Sinomenine pretreatment alleviates hepatic ischemia/reperfusion injury through activating Nrf-2/HO-1 pathway

INTRODUCTION

Ischemia-reperfusion (IR) injury is induced by an interrupted blood flow and succeeding blood restoration, which is common in the operation of liver transplantation. Serious IR injury is a major reason leading to transplant failure. Hepatic IR is featured by excessive inflammatory response, oxidative stress, and apoptosis. Sinomenine (SIN) is derived from the herb Sinomeniumacutum and shows properties of anti-inflammation and antiapoptosis in multiple IR-induced organ injuries. However, the effect of SIN in hepatic IR has not been investigated.

METHODS

This study aims to investigate impacts of SIN on hepatic IR and the involved signaling pathway. An in vivo rat model of syngeneic orthotopic liver transplantation was constructed to induce the hepatic IR injury.

RESULTS

Results showed that SIN pretreatment provided a significant prevention against IR-induced hepatic injury as manifested by the downregulated activities of serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase, the alleviatedoxidative stress as shown by increased activities of serum superoxide dismutase and glutathione peroxidase, and decreased serum level of malondialdehyde, the suppressed inflammatory responses as shown by downregulated serum tumor necrosis factor-α, interleukin (IL)-6, IL-8 levels, and upregulated IL-10 level, as well as attenuated apoptosis as shown by decreased protein expression of cleaved caspase-3 and -9. In line with these results, SIN pretreatment also alleviatedthe hepatic histopathological changes in IR rats and induced Nrf-2/HO-1 activation. The use of brusatol, a selective inhibitor for Nrf-2, effectively reversed SIN-induced above effects.

CONCLUSIONS

Altogether, our results demonstrate that SIN might be a useful therapeutic drug for preventing hepatic IR-induced injury during clinical liver transplantation.

α-Lipoic Acid Protects against Cyclosporine A-Induced Hepatic Toxicity in Rats: Effect on Oxidative Stress, Inflammation, and Apoptosis

The clinical application of cyclosporine A (CsA) as an immunosuppressive agent is limited by its organ toxicity. We aimed to evaluate the effectiveness of α-lipoic acid against CsA-induced hepatotoxicity and to delineate the underlying molecular mechanisms. Male Wistar rats (n = 24, 8 per each group) received the vehicle, CsA (25 mg/kg) and/or ALA (100 mg/kg, p.o.) for 3 weeks. Biochemical markers of liver function (serum ALT, AST, ALP < GGT), oxidative stress (MDA, TAC, SOD, GSH, Nrf2/HO-1), inflammation (NF-κB, CD68, iNOS, NO, COX-2), and apoptosis (caspase-3) were assessed in serum and tissue. Liver histological analysis using H&E and Sirius red was performed. The development of liver injury in CsA-treated animals was indicated by elevated levels of liver enzymes, oxidants/antioxidants imbalance, inflammatory cells infiltration, up-regulated expression of inflammatory mediators, and apoptosis. These changes were associated with altered architecture of hepatic cells and fibrous connective tissue. ALA co-administration protected against CsA-induced liver damage and ameliorated biochemical changes and cellular injury. In conclusion, ALA demonstrated hepatoprotective potential against CsA-induced liver injury through combating oxidative stress, inflammation, and apoptosis, highlighting ALA as a valuable adjunct to CsA therapy.

Cordycepin Protects against Hepatic Ischemia/Reperfusion Injury via Inhibiting MAPK/NF-κB Pathway

Hepatic ischemia/reperfusion injury (HIRI) is a common complication of liver surgery requiring hepatic disconnection, such as hepatectomy and liver transplantation. The aim of this study was to investigate the effects of cordycepin on HIRI and to elucidate the underlying mechanisms. Balb/c mice were randomly divided into six groups: a normal control group, sham group, H-cordycepin group, HIRI group, L-cordycepin (25 mg/kg) + HIRI group, and H-cordycepin (50 mg/kg) + HIRI group. Mice were subjected to I/R, and cordycepin was intragastrically administered for seven consecutive days before surgery. Orbital blood and liver specimens were collected at 6 and 24 h after HIRI. Serum levels of ALT and AST were decreased in the cordycepin pretreatment groups. Notably, cordycepin attenuated the inflammatory response and the production of proapoptosis proteins, while increasing expression of antiapoptosis proteins and decreasing expression of autophagy-linked proteins. Furthermore, cordycepin inhibited activation of the MAPK/NF-κB signaling pathway. Collectively, these results indicate that cordycepin pretreatment ameliorated hepatocyte injury caused by HIRI. As compared with the HIRI group, cordycepin pretreatment mitigated the inflammatory response and inhibited apoptosis and autophagy via regulation of the MAPK/NF-κB signaling pathway.

Albendazole ameliorates inflammatory response in a rat model of acute mesenteric ischemia reperfusion injury

BACKGROUND

Acute mesenteric ischemia is known as a life threatening condition. Re-establishment of blood flow in this condition can lead to mesenteric ischemia reperfusion (MIR) injury which is accompanied by inflammatory response. Still, clear blueprint of inflammatory mechanism underlying MIR injury has not been provided. Interestingly, Albendazole has exhibited notable effects on inflammation and cytokine production. In this study, we aimed to evaluate outcomes of MIR injury following pretreatment with Albendazole with respect to assessment of mesenteric inflammation and ischemia threshold.

METHODS

Male rats were randomly divided into sham operated, vehicle treated, Albendazole 100 mg/kg and Albendazole 200 mg/kg groups. MIR injury was induced by occlusion of superior mesenteric artery for 30 min followed by 120 min of reperfusion. Samples were utilized for assessment of epithelial survival and villous height. Immunohistochemistry study revealed intestinal expression of TNF-α and HIF-1-α. Gene expression of NF-κB/TLR4/TNF-α/IL-6 was measured using RTPCR. Also protein levels of inflammatory cytokines in serum and intestine were assessed by ELISA method.

RESULTS

Histopathological study demonstrated that pretreatment with Albendazole could ameliorate decline in villous height and epithelial survival following MIR injury. Also, systemic inflammation was suppressed after administration of Albendazole. Analysis of possible participating inflammatory pathway could demonstrate that intestinal expression of NF-κB/TLR4/TNF-α/IL-6 is significantly attenuated in treated groups. Eventually, IHC study illustrated concordant decline in mesenteric expression of HIF-1-α/TNF-α.

CONCLUSION

Single dose pretreatment with Albendazole could ameliorate inflammatory response and enhance ischemia threshold following induction of MIR injury. More studies would clarify existing causality in this phenomenon.

Vildagliptin alleviates liver fibrosis in NASH diabetic rats via modulation of insulin resistance, oxidative stress, and inflammatory cascades

AIMS

This study investigates the therapeutic potential of Vilda in a NASH model with liver fibrosis and elucidates the underlying molecular mechanisms.

MAIN METHODS

To induce NASH, male Sprague-Dawley rats were fed a high-fat diet for 24 weeks with a single dose of STZ (40 mg/kg, IP). Vilda was orally administered at two doses (10 and 20 mg/kg) for 20 weeks.

KEY FINDINGS

The induction of NASH was validated by abnormalities in hepatotoxicity indices, lipid profile, oxidative stress markers, and pathologically by marked fat deposition in hepatic tissues together with severe inflammatory cell infiltration. Moreover, NASH-affected rats demonstrated reduced insulin sensitivity manifested as elevated fasting blood glucose levels and disrupted homeostasis model assessment for insulin resistance. Vilda, at both doses, effectively abrogated all these pathological features of NASH. Mechanistically, these hepatoprotective properties of Vilda can be attributed to its antioxidant effects, anti-inflammatory effects (by inhibiting the TNF-α, NF-κB, JNK, and JAK/STAT pathways), and insulin-sensitizing effect (by upregulating the IRS-1/PI3K/Akt pathway). Besides, Vilda successfully counteracted NASH-associated liver fibrosis by downregulating the TGF-β1 pathway.

SIGNIFICANCE

The hepatoprotective and antifibrotic effects of Vilda were mostly dose-dependent. Collectively, this study offered a promising therapeutic avenue for Vilda as a novel strategy for counteracting the pathological progression of NASH and associated liver fibrosis.

Transcriptional changes in orthotopic liver transplantation and ischemia/reperfusion injury

Background There are few effective targeting strategies to reduce liver ischemia-reperfusion injury (IRI), which is one of the reasons for the poor prognosis of liver transplant recipients. Methods A systematic approach combining gene expression with protein interaction (PPI) network was used to screen the characteristic genes and related biological functions of post-transplant. Differentially expressed genes (DEGs) between IRI+ and IRI- were identified. Logistic regression model and receiver operating characteristic (ROC) curve were used to identify potential target genes of IRI. The expression of key genes was verified by qRT-PCR and Western-blot experiments. Finally, the ssGSEA was used to identify the immune cell infiltration in patients with IRI. Results The 283 common DEGs in GSE87487 and GSE151648 were mainly related to apoptosis and IL-17 signaling pathway. Through PPI network and logistic regression analysis, we identified that IL6, CCL2 and CXCL8 may be involved in the ischemia/reperfusion (IR) process. In addition, 32 genes were showed associated with IRI through inflammatory and metabolic pathways. Among the key genes identified, the differential expression of AGBL4, CILP2 and IL4I1 was verified by molecular experiments. Th17 cells of differentially infiltrated immune cells were positively correlated with CILP2 and IL4I1. The difference of Th17 cells between IRI+ and IRI- was verified by flow cytometry. Conclusion The study showed that AGBL4, CILP2 and IL4I1 were associated with IRI. Th17 cells may be associated with the regulation of IRI by key genes. These genes and related pathways may be targets for improving IRI.

New progress in understanding roles of nitric oxide during hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (HIRI) is a major clinical cause of morbidity and mortality in liver surgery and transplantation. Many studies have found that nitric oxide (NO) plays an important role in the HIRI and its increase or decrease can affect the progression and outcome of HIRI. However, the role of NO in HIRI is controversial and complicated. NO derived by endothelial NO synthase (eNOS) shows a protective role in HIRI, while excessive NO derived by inducible NO synthase (iNOS) accelerates inflammation and increases oxidative stress, further aggravating HIRI. Nevertheless, the overexpression of eNOS may exacerbate HIRI and iNOS-derived NO in some cases reduces HIRI. Here we review the new progress in the understanding of the roles of NO during HIRI: (1) NO possesses different roles in HIRI by increasing NO bioavailability, down-regulating leukotriene C4 synthase, inhibiting the activation of the nuclear factorκB (NFκB) pathway, enhancing cell autophagy, and reducing inflammatory cytokines and reactive oxygen species (ROS). And NO has both protective and deleterious effects by regulating apoptotic factors; (2) eNOS promotes NO production and suppresses its own overexpression, exerting a hepatoprotective effect reversely. Its activation is regulated by the PI3K/Akt and KLF2/AMPK pathways; and (3) iNOS derived NO mainly has deteriorating effects on HIRI, while it may have a protective function under some conditions. Their expression should reach a balance to reduce the adverse side and make NO protective in the treatment of HIRI. Thus, it can be inferred that NO modulating drugs may be a new direction in the treatment of HIRI or may be used as an adjunct to mitigate HIRI for the purpose of protecting the liver.

Neuroprotective Effects of the DPP4 Inhibitor Vildagliptin in In Vivo and In Vitro Models of Parkinson's Disease

Parkinson’s disease (PD) is characterized by loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) of the midbrain. Restoration of nigrostriatal dopamine neurons has been proposed as a potential therapeutic strategy for PD. Because currently used PD therapeutics only help relieve motor symptoms and do not treat the cause of the disease, highly effective drugs are needed. Vildagliptin, a dipeptidyl peptidase 4 (DPP4) inhibitor, is an anti-diabetic drug with various pharmacological properties including neuroprotective effects. However, the detailed effects of vildagliptin against PD are not fully understood. We investigated the effects of vildagliptin on PD and its underlying molecular mechanisms using a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model and a 1-methyl-4-phenylpyridium (MPP⁺)-induced cytotoxicity model. Vildagliptin (50 mg/kg) administration significantly attenuated MPTP-induced motor deficits as evidenced by rotarod, pole, and nest building tests. Immunohistochemistry and Western blot analysis revealed that vildagliptin increased tyrosine hydroxylase-positive cells in the SNpc and striatum, which was reduced by MPTP treatment. Furthermore, vildagliptin activated MPTP-decreased PI3k/Akt and mitigated MPTP-increased ERK and JNK signaling pathways in the striatum. Consistent with signaling transduction in the mouse striatum, vildagliptin reversed MPP⁺-induced dephosphorylation of PI3K/Akt and phosphorylation of ERK and JNK in SH-SY5Y cells. Moreover, vildagliptin attenuated MPP⁺-induced conversion of LC3B-II in SH-SY5Y cells, suggesting its role in autophagy inhibition. Taken together, these findings indicate that vildagliptin has protective effects against MPTP-induced motor dysfunction by inhibiting dopaminergic neuronal apoptosis, which is associated with regulation of PI3k/Akt, ERK, and JNK signaling transduction. Our findings suggest vildagliptin as a promising repurposing drug to treat PD.

Protective mechanisms of telmisartan against hepatic ischemia/reperfusion injury in rats may involve PPARγ-induced TLR4/NF-κB suppression

Hepatic ischemia-reperfusion (I/R) is an important cause of liver damage in many clinical situations. Toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) is an inflammatory pathway activated in hepatic I/R injury. Telmisartan, a selective angiotensin II type 1 receptor antagonist and peroxisome proliferator-activated receptor-gamma (PPARγ) partial agonist, can inhibit the expression of pro-inflammatory cytokines. The present work investigated the possible protective effect of telmisartan against hepatic I/R injury and explored its possible mechanisms in rats. Rats were divided into four equal groups: sham-operated control, telmisartan-treated sham-operated control, I/R untreated, and I/R telmisartan-treated groups. Hepatic injury was evaluated biochemically by serum activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and histopathological examination. Hepatic oxidative stress biomarkers, myeloperoxidase level, PPARγ and TLR4 mRNA expression, and NF-κB and active caspase 3 immunoexpression were determined. The study showed that telmisartan attenuated hepatic I/R, as evidenced by decreased serum ALT and AST activities and confirmed by improvement of the histopathological changes. The protective effect of telmisartan was associated with modulation of oxidative stress parameters, myeloperoxidase level, PPARγ and TLR4 mRNA expression, and NF-κB and caspase 3 immunoexpression. Taken together, the current study showed that telmisartan could protect the rat liver from I/R injury. This hepatoprotective effect was attributed to, at least in part, increase in PPARγ expression and suppression of TLR4/NF-κB pathway.

Modulation of Prostanoids Profile and Counter-Regulation of SDF-1α/CXCR4 and VIP/VPAC2 Expression by Sitagliptin in Non-Diabetic Rat Model of Hepatic Ischemia-Reperfusion Injury

Molecular mechanisms underlying the beneficial effect of sitagliptin repurposed for hepatic ischemia-reperfusion injury (IRI) are poorly understood. We aimed to evaluate the impact of IRI and sitagliptin on the hepatic profile of eicosanoids (LC-MS/MS) and expression/concentration (RTqPCR/ELISA) of GLP-1/GLP-1R, SDF-1α/CXCR4 and VIP/VPAC1, VPAC2, and PAC1 in 36 rats. Animals were divided into four groups and subjected to ischemia (60 min) and reperfusion (24 h) with or without pretreatment with sitagliptin (5 mg/kg) (IR and SIR) or sham-operated with or without sitagliptin pretreatment (controls and sitagliptin). PGI₂, PGE₂, and 13,14-dihydro-PGE₁ were significantly upregulated in IR but not SIR, while sitagliptin upregulated PGD₂ and 15-deoxy-12,14-PGJ₂. IR and sitagliptin non-significantly upregulated GLP-1 while Glp1r expression was borderline detectable. VIP concentration and Vpac2 expression were downregulated in IR but not SIR, while Vpac1 was significantly downregulated solely in SIR. IRI upregulated both CXCR4 expression and concentration, and sitagliptin pretreatment abrogated receptor overexpression and downregulated Sdf1. In conclusion, hepatic IRI is accompanied by an elevation in proinflammatory prostanoids and overexpression of CXCR4, combined with downregulation of VIP/VPAC2. Beneficial effects of sitagliptin during hepatic IRI might be mediated by drug-induced normalization of proinflammatory prostanoids and upregulation of PGD₂ and by concomitant downregulation of SDF-1α/CXCR4 and reinstating VIP/VCAP2 signaling.

Umbelliferone alleviates hepatic ischemia/reperfusion-induced oxidative stress injury via targeting Keap-1/Nrf-2/ARE and TLR4/NF-κB-p65 signaling pathway

Umbelliferone (UMB; 7-hydroxycoumarin) is a natural compound that exhibited a diversity of pharmacological activities. Its protective effects against various ischemia/reperfusion (IR) injuries, including heart, kidney, and testis, have been observed. However, their effect on hepatic IR is still not investigated yet. Here, this study was conducted to examine the potential protective role of UMB during the early phase of hepatic IR injury via targeting Keap-1/Nrf-2/ARE and its closely related signaling pathway, TLR4/NF-κB-p65. Experimentally, forty Wistar albino rats were randomly divided into 4 groups: Sham control group (received 1% carboxymethyl cellulose as a vehicle), UMB group (30 mg/kg/day, P.O.), IR group (subjected to complete hepatic IR injury), and IR + UMB group. Our results revealed that oral UMB effectively reduced the serum levels of ALT, AST, ALP, and LDH along with the restoration of oxidant/antioxidant status. At the molecular level, UMB markedly activated Nrf-2 expression and its down-streaming targets: HO-1, NQO1, GCLC, SOD3, and TNXRD1, along with Keap-1 down-regulation. Besides, UMB significantly down-regulated NF-κB-p65 and TLR4 expressions with subsequent decreased TNF-α and IL-1β levels coupled with the up-regulation of the IL-10 level. Finally, biochemical findings were confirmed by attenuation of histopathological changes in liver tissues. Together, UMB is a promising agent for the amelioration of liver tissues against IR-induced oxidative injury through activation of the Keap-1/Nrf-2/ARE signaling pathway along with suppression of its closely related signaling pathways: TLR4/NF-κB-p65. Illustrated diagram explored the prospective underlying protective mechanism of UMB against IR-induced hepatic damage.

Irisin Protects Against LPS-Stressed Cardiac Damage Through Inhibiting Inflammation, Apoptosis, and Pyroptosis

ABSTRACT

Septic cardiac dysfunction remains a clinical problem due to its high morbidity and mortality. Uncontrolled cell death and excessive inflammatory response are closely related to sepsis-induced cardiac dysfunction. Irisin has been found to play cardioprotective roles in sepsis. However, there is enough uncertainty in the mechanism of irisin-mediated cardioprotection. We hypothesized that irisin may ameliorate myocardial dysfunction via reducing cardiac apoptosis, pyroptosis, and inflammation during LPS-induced sepsis. Mice were subjected to LPS with or without irisin treatment. After stimuli of LPS, the function of myocardium was distinctly impaired, which was closely related to increased level of apoptosis (decreased expression of Bcl-2 and elevated expression of Caspase-3 and Bax), pyroptosis (increased expression of Caspase1, NLR family pyrin domain containing 3 (NLRP3), and gasdermin D) and inflammatory mediators (increased level of IL-1β, TNF-α, and IL-6). This process is consistent with increased toll-like receptor 4 (TLR4)/nuclear factor-kappa B signal, apoptotic signal, and NLRP3-mediated pyroptotic signal. Activation of apoptosis and pyroptosis enhanced the expression of proinflammatory cytokines and further exacerbated septic myocardial damage. However, irisin can inhibit the expression of TLR4 and its downstream signaling molecules and also lower the level of apoptosis and pyroptosis. Besides, similar results were also found in vitro model of LPS-induced H9c2 cardiomyocyte injury. In general, irisin suppressed inflammation, apoptosis, and pyroptosis by blocking the TLR4 and NLRP3 inflammasome signalings to mitigate myocardial dysfunction in sepsis.

Inhibition of microRNA-297 alleviates THLE-2 cell injury induced by hypoxia/reoxygenation by inhibiting NLRP3 inflammasome activation via SIRT3

It has been acknowledged that microRNAs (miRNAs/miRs) assume a critical role in hypoxia/reoxygenation (H/R)-induced hepatocyte injury. Therefore, cell experiments were performed in this study to investigate the mechanism of miR-297 in H/R-induced hepatocyte injury with the involvement of Sirtuin 3 (SIRT3) and NLRP3. Initially, THLE-2 cells were utilized for H/R challenge. After miR-297 antagomir and NLRP3 adenovirus vector delivery, THLE-2 cell proliferation and apoptosis were measured by MTT, EdU and TUNEL assays, respectively. Enzyme-linked immunosorbent assay was conducted to evaluate the levels of apoptosis-related indicators (Bax and Bcl-2) and inflammation-related indicators (IL-6 and IL-10), western blot analysis to detect NLRP3 and Cleaved Caspase-1 expression. The binding relation between miR-297 and SIRT3 was examined using dual-luciferase assay. The results showed that miR-297 antagomir repressed the apoptosis and inflammation induced by H/R treatment in THLE-2 cells. Mechanistically, miR-297 antagomir diminished the extent of IκBα and NF-κB phosphorylation and NLRP3 activation in H/R-induced THLE-2 cells by targeting SIRT3. Furthermore, NLRP3 overexpression normalized the promoting effects of miR-297 antagomir on proliferation and its inhibitory effects on apoptosis and inflammation in H/R-induced THLE-2 cells. In summary, our results elucidated that miR-297 antagomir repressed H/R-induced THLE-2 cell injury via SIRT3 promotion and NLRP3 inactivation.

GAB1 alleviates septic lung injury by inhibiting the TLR4/ NF-κB pathway

Sepsis, with its high morbidity and mortality, is a difficult problem in critical care medicine. The purpose of this study is to investigate the involvement of GRB2-associated binding protein 1 (GAB1) in septic lung injury. Lipopolysaccharide (LPS)-induced mouse model and A549 cell model were used to simulate septic lung injury. Haematoxylin and eosin (H&E) staining was used to observe the pathological changes. The terminal-deoxynucleotidyl transferase/(TdT)-mediated dUTP-biotin nick end labelling (TUNEL) staining and flow cytometry were used to detect apoptosis. The levels of inflammatory factors in the bronchoalveolar lavage fluid (BALF) were determined by enzyme-linked immunosorbent assay (ELISA). In LPS-induced sepsis mice, GAB1 expression was markedly reduced, and GAB1 overexpression significantly attenuated cell apoptosis and decreased levels of macrophages, neutrophils, and inflammatory factors in the BALF. Our results also demonstrated that GAB1 overexpression significantly reduced LPS-induced apoptosis and inflammation of A549 cells. More importantly, GAB1 overexpression significantly inhibited the Toll-like receptor/ NFkappaB (TLR4/NF-κB) pathway, while silencing GAB1 significantly activated the TLR4/NF-κB pathway and induced apoptosis and increased expression of inflammatory factors. However, the TLR4 inhibitor TAK-242 eliminated the effect of GAB1 silencing on A549. In conclusion, GAB1 is a key regulator of sepsis by inhibiting TLR4/NF-κB mediated apoptosis and inflammation.

Role of TLR-4/IL-6/TNF-α, COX-II and eNOS/iNOS pathways in the impact of carvedilol against hepatic ischemia reperfusion injury

AIM

Hepatic ischemia/reperfusion (I/R) injury is a syndrome involved in allograft dysfunction. This work aimed to elucidate carvedilol (CAR) role in hepatic I/R injury.

METHODS

Male rats were allocated to Sham group, CAR group, I/R group and CAR plus I/R group. Rats subjected to hepatic ischemia for 30 minutes then reperfused for 60 minutes. Oxidative stress markers, inflammatory cytokines and nitric oxide synthases were measured in hepatic tissues.

RESULTS

Hepatocyte injury following I/R was confirmed by a marked increase in liver enzymes. Also, hepatic I/R increased the contents of malondialdehyde however decreased glutathione contents and activities of antioxidant enzymes. Furthermore, hepatic I/R caused elevation of toll-like receptor-4 (TLR-4) expression and inflammatory mediators levels such as tumor necrosis factor-α, interleukin-6 and cyclooxygenase-II. Hepatic I/R caused down-regulation of endothelial nitric oxide synthase and upregulation of inducible nitric oxide synthase expressions. CAR treatment before hepatic I/R resulted in the restoration of liver enzymes. Administration of CAR caused a significant correction of oxidative stress and inflammation markers as well as modulates the expression of endothelial and inducible nitric oxide synthase.

CONCLUSIONS

CAR protects liver from I/R injury through reduction of the oxidative stress and inflammation, and modulates endothelial and inducible nitric oxide synthase expressions.

Sitagliptin Modulates Oxidative, Nitrative and Halogenative Stress and Inflammatory Response in Rat Model of Hepatic Ischemia-Reperfusion

A possibility of repurposing sitagliptin, a well-established antidiabetic drug, for alleviating injury caused by ischemia-reperfusion (IR) is being researched. The aim of this study was to shed some light on the molecular background of the protective activity of sitagliptin during hepatic IR. The expression and/or concentration of inflammation and oxidative stress-involved factors have been determined in rat liver homogenates using quantitative RT-PCR and Luminex^® xMAP^® technology and markers of nitrative and halogenative stress were quantified using targeted metabolomics (LC-MS/MS). Animals (n = 36) divided into four groups were treated with sitagliptin (5 mg/kg) (S and SIR) or saline solution (C and IR), and the livers from IR and SIR were subjected to ischemia (60 min) and reperfusion (24 h). The midkine expression (by 2.2-fold) and the free 3-nitrotyrosine (by 2.5-fold) and IL-10 (by 2-fold) concentration were significantly higher and the Nox4 expression was lower (by 9.4-fold) in the IR than the C animals. As compared to IR, the SIR animals had a lower expression of interleukin-6 (by 4.2-fold) and midkine (by 2-fold), a lower concentration of 3-nitrotyrosine (by 2.5-fold) and a higher Nox4 (by 2.9-fold) and 3-bromotyrosine (by 1.4-fold). In conclusion, IR disturbs the oxidative, nitrative and halogenative balance and aggravates the inflammatory response in the liver, which can be attenuated by low doses of sitagliptin.

The Role of Mitochondria in Liver Ischemia-Reperfusion Injury: From Aspects of Mitochondrial Oxidative Stress, Mitochondrial Fission, Mitochondrial Membrane Permeable Transport Pore Formation, Mitophagy, and Mitochondria-Related Protective Measures

Ischemia-reperfusion injury (IRI) has indeed been shown as a main complication of hepatectomy, liver transplantation, trauma, and hypovolemic shock. A large number of studies have confirmed that microvascular and parenchymal damage is mainly caused by reactive oxygen species (ROS), which is considered to be a major risk factor for IRI. Under normal conditions, ROS as a kind of by-product of cellular metabolism can be controlled at normal levels. However, when IRI occurs, mitochondrial oxidative phosphorylation is inhibited. In addition, oxidative respiratory chain damage leads to massive consumption of adenosine triphosphate (ATP) and large amounts of ROS. Additionally, mitochondrial dysfunction is involved in various organs and tissues in IRI. On the one hand, excessive free radicals induce mitochondrial damage, for instance, mitochondrial structure, number, function, and energy metabolism. On the other hand, the disorder of mitochondrial fusion and fission results in further reduction of the number of mitochondria so that it is not enough to clear excessive ROS, and mitochondrial structure changes to form mitochondrial membrane permeable transport pores (mPTPs), which leads to cell necrosis and apoptosis, organ failure, and metabolic dysfunction, increasing morbidity and mortality. According to the formation mechanism of IRI, various substances have been discovered or synthesized for specific targets and cell signaling pathways to inhibit or slow the damage of liver IRI to the body. Here, based on the development of this field, this review describes the role of mitochondria in liver IRI, from aspects of mitochondrial oxidative stress, mitochondrial fusion and fission, mPTP formation, and corresponding protective measures. Therefore, it may provide references for future clinical treatment and research.

Resolving the graft ischemia-reperfusion injury during liver transplantation at the single cell resolution

Ischemia–reperfusion injury (IRI) remains the major reason for impaired donor graft function and increased mortality post-liver transplantation. The mechanism of IRI involves multiple pathophysiological processes and numerous types of cells. However, a systematic and comprehensive single-cell transcriptional profile of intrahepatic cells during liver transplantation is still unclear. We performed a single-cell transcriptome analysis of 14,313 cells from liver tissues collected from pre-procurement, at the end of preservation and 2 h post-reperfusion. We made detailed annotations of mononuclear phagocyte, endothelial cell, NK/T, B and plasma cell clusters, and we described the dynamic changes of the transcriptome of these clusters during IRI and the interaction between mononuclear phagocyte clusters and other cell clusters. In addition, we found that TNFAIP3 interacting protein 3 (TNIP3), specifically and highly expressed in Kupffer cell clusters post-reperfusion, may have a protective effect on IRI. In summary, our study provides the first dynamic transcriptome map of intrahepatic cell clusters during liver transplantation at single-cell resolution.

The effect of dipeptidyl peptidase IV on disease-associated microglia phenotypic transformation in epilepsy

BACKGROUND

Accumulating evidence suggests that disease-associated microglia (DAM), a recently discovered subset of microglia, plays a protective role in neurological diseases. Targeting DAM phenotypic transformation may provide new therapeutic options. However, the relationship between DAM and epilepsy remains unknown.

METHODS

Analysis of public RNA-sequencing data revealed predisposing factors (such as dipeptidyl peptidase IV; DPP4) for epilepsy related to DAM conversion. Anti-epileptic effect was assessed by electroencephalogram recordings and immunohistochemistry in a kainic acid (KA)-induced mouse model of epilepsy. The phenotype, morphology and function of microglia were assessed by qPCR, western blotting and microscopic imaging.

RESULTS

Our results demonstrated that DPP4 participated in DAM conversion and epilepsy. The treatment of sitagliptin (a DPP4 inhibitor) attenuated KA-induced epilepsy and promoted the expression of DAM markers (Itgax and Axl) in both mouse epilepsy model in vivo and microglial inflammatory model in vitro. With sitagliptin treatment, microglial cells did not display an inflammatory activation state (enlarged cell bodies). Furthermore, these microglia exhibited complicated intersections, longer processes and wider coverage of parenchyma. In addition, sitagliptin reduced the activation of NF-κB signaling pathway and inhibited the expression of iNOS, IL-1β, IL-6 and the proinflammatory DAM subset gene CD44.

CONCLUSION

The present results highlight that the DPP4 inhibitor sitagliptin can attenuate epilepsy and promote DAM phenotypic transformation. These DAM exhibit unique morphological features, greater migration ability and better surveillance capability. The possible underlying mechanism is that sitagliptin can reduce the activation of NF-κB signaling pathway and suppress the inflammatory response mediated by microglia. Thus, we propose DPP4 may act as an attractive direction for DAM research and a potential therapeutic target for epilepsy.

Synergistic effect of the TLR5 agonist CBLB502 and its downstream effector IL-22 against liver injury

The toll-like receptor 5 (TLR5) agonist, CBLB502/Entolimod, is a peptide derived from bacterial flagellin and has been shown to protect against radiation-induced tissue damage in animal models. Here we investigated the protective mechanism of CBLB502 in the liver using models of ischemia-reperfusion injury and concanavalin A (ConA) induced immuno-hepatitis. We report that pretreatment of mice with CBLB502 provoked a concomitant activation of NF-κB and STAT3 signaling in the liver and reduced hepatic damage in both models. To understand the underlying mechanism, we screened for cytokines in the serum of CBLB502 treated animals and detected high levels of IL-22. There was no transcriptional upregulation of IL-22 in the liver, rather it was found in extrahepatic tissues, mainly the colon, mesenteric lymph nodes (MLN), and spleen. RNA-seq analysis on isolated hepatocytes demonstrated that the concomitant activation of NF-κB signaling by CBLB502 and STAT3 signaling by IL-22 produced a synergistic cytoprotective transcriptional signature. In IL-22 knockout mice, the loss of IL-22 resulted in a decrease of hepatic STAT3 activation, a reduction in the cytoprotective signature, and a loss of hepatoprotection following ischemia-reperfusion-induced liver injury. Taken together, these findings suggest that CBLB502 protects the liver by increasing hepatocyte resistance to acute liver injury through the cooperation of TLR5-NF-κB and IL-22-STAT3 signaling pathways.

DUSP12 protects against hepatic ischemia-reperfusion injury dependent on ASK1-JNK/p38 pathway in vitro and in vivo

Hepatic ischemia-reperfusion (I/R) injury is an important risk factor resulting in liver failure during liver surgery. However, there is still lack of effective therapeutic methods to treat hepatic I/R injury. DUSP12 is a member of the dual specific phosphatase (DUSP) family. Some DUSPs have been identified as being involved in the regulation of hepatic I/R injury. However, the role of DUSP12 during hepatic I/R injury is still unclear. In the present study, we observed a significant decrease in DUSP12 expression in a hepatic I/R injury mouse model in vivo and in hypoxia/reoxygenation (H/R) model in vitro. Using hepatocyte-specific DUSP12 knockout mice and DUSP12 transgenic mice, we demonstrated that DUSP12 apparently relieved I/R-induced liver injury. Moreover, DUSP12 inhibited hepatic inflammatory responses and alleviated apoptosis both in vitro and in vivo. Furthermore, we demonstrated that JNK and p38 activity, but not ERK1/2, was increased in the DUSP12-deficient mice and decreased in the DUSP12 transgenic mice under I/R condition. ASK1 was required for DUSP12 function in hepatic I/R injury and inhibition of ASK1 prevented inflammation and apoptosis in DUSP12-deficient hepatocytes and mice. In conclusion, DUSP12 protects against hepatic I/R injury and related inflammation and apoptosis. This regulatory role of DUSP12 is primarily through ASK1-JNK/p38 signaling pathway. Taken together, DUSP12 could be a potential therapeutic target for hepatic I/R injury.

The protective effect of hesperidin against renal ischemia-reperfusion injury involves the TLR-4/NF-κB/iNOS pathway in rats

Renal injury is reported to have a high mortality rate. Additionally, there are several limitations to current conventional treatments that are used to manage it. This study evaluated the protective effect of hesperidin against ischemia/reperfusion (I/R)-induced kidney injury in rats. Renal injury was induced by generating I/R in kidney tissues. Rats were then treated with hesperidin at a dose of 10 or 20 mg/kg intravenously 1 day after surgery for a period of 14 days. The effect of hesperidin on renal function, serum mediators of inflammation, and levels of oxidative stress in renal tissues were observed in rat kidney tissues after I/R-induced kidney injury. Moreover, protein expression and mRNA expression in kidney tissues were determined using Western blotting and RT-PCR. Hematoxylin and eosin (H&E) staining was done for histopathological observation of kidney tissues. The data suggest that the levels of blood urea nitrogen (BUN) and creatinine in the serum of hesperidin-treated rats were lower than in the I/R group. Treatment with hesperidin also ameliorated the altered level of inflammatory mediators and oxidative stress in I/R-induced renal-injured rats. The expression of p-IκBα, caspase-3, NF-κB p65, Toll-like receptor 4 (TLR-4) protein, TLR-4 mRNA, and inducible nitric oxide synthase (iNOS) was significantly reduced in the renal tissues of hesperidin-treated rats. Histopathological findings also revealed that treatment with hesperidin attenuated the renal injury in I/R kidney-injured rats. In conclusion, our results suggest that hesperidin protects against renal injury induced by I/R by involving TLR-4/NF-κB/iNOS signaling.

Tissue-Specific Hydrogels Ameliorate Hepatic Ischemia/Reperfusion Injury in Rats by Regulating Macrophage Polarization via TLR4/NF-κB Signaling

Injectable acellular matrix hydrogels are proven to be potential translational materials to facilitate the repairment in various tissues. However, their potential to repair hepatic ischemia/reperfusion injury (IRI) has not been explored. In this work, we made hepatic acellular matrix (HAM) hydrogels based on the decellularized process and evaluated the biocompatibility and hepatoprotective effects in a rat IRI model. HAM hydrogels supported viability, proliferation, and attachment of hepatocytes in vitro. Treatment with HAM hydrogels significantly attenuated hepatic damage caused by IRI, as evidenced by hepatic biochemistry, histology, and inflammatory responses. Importantly, HAM hydrogels inhibited macrophage M1 (CD68/CCR7) differentiation but promoted M2 (CD68/CD206) differentiation. Additionally, TLR4/NF-κB signaling was found to be involved in the hepatoprotective effect of HAM hydrogels. Collectively, our study reveals that HAM hydrogels ameliorate hepatic IRI by facilitating M2 polarization via TLR4/NF-κB signaling.

microRNA-130a-5p suppresses myocardial ischemia reperfusion injury by downregulating the HMGB2/NF-κB axis

BACKGROUND

Myocardial ischemia reperfusion injury (MIRI) is defined as tissue injury in the pathological process of progressive aggravation in ischemic myocardium after the occurrence of acute coronary artery occlusion. Research has documented the involvement of microRNAs (miRs) in MIRI. However, there is obscure information about the role of miR-130a-5p in MIRI. Herein, this study aims to investigate the effect of miR-130a-5p on MIRI.

METHODS

MIRI mouse models were established. Then, the cardiac function and hemodynamics were detected using ultrasonography and multiconductive physiological recorder. Functional assays in miR-130a-5p were adopted to test the degrees of oxidative stress, mitochondrial functions, inflammation and apoptosis. Hematoxylin and eosin (HE) staining was performed to validate the myocardial injury in mice. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was employed to assess the expression patterns of miR-130a-5p, high mobility group box (HMGB)2 and NF-κB. Then, dual-luciferase reporter gene assay was performed to elucidate the targeting relation between miR-130a-5p and HMGB2.

RESULTS

Disrupted structural arrangement in MIRI mouse models was evident from HE staining. RT-qPCR revealed that overexpressed miR-130a-5p alleviated MIRI, MIRI-induced oxidative stress and mitochondrial disorder in the mice. Next, the targeting relation between miR-130a-5p and HMGB2 was ascertained. Overexpressed HMGB2 annulled the protective effects of miR-130a-5p in MIRI mice. Additionally, miR-130a-5p targets HMGB2 to downregulate the nuclear factor kappa-B (NF-κB) axis, mitigating the inflammatory injury induced by MIRI.

CONCLUSION

Our study demonstrated that miR-130a-5p suppresses MIRI by down-regulating the HMGB2/NF-κB axis. This investigation may provide novel insights for development of MIRI treatments.

Alogliptin Attenuates Lipopolysaccharide-Induced Neuroinflammation in Mice Through Modulation of TLR4/MYD88/NF-κB and miRNA-155/SOCS-1 Signaling Pathways

BACKGROUND

Endotoxin-induced neuroinflammation plays a crucial role in the pathogenesis and progression of various neurodegenerative diseases. A growing body of evidence supports that incretin-acting drugs possess various neuroprotective effects that can improve learning and memory impairments in Alzheimer's disease models. Thus, the present study aimed to investigate whether alogliptin, a dipeptidyl peptidase-4 inhibitor, has neuroprotective effects against lipopolysaccharide (LPS)-induced neuroinflammation and cognitive impairment in mice as well as the potential mechanisms underlying these effects.

METHODS

Mice were treated with alogliptin (20 mg/kg/d; p.o.) for 14 days, starting 1 day prior to intracerebroventricular LPS injection (8 μg/μL in 3 μL).

RESULTS

Alogliptin treatment alleviated LPS-induced cognitive impairment as assessed by Morris water maze and novel object recognition tests. Moreover, alogliptin reversed LPS-induced increases in toll-like receptor 4 and myeloid differentiation primary response 88 protein expression, nuclear factor-κB p65 content, and microRNA-155 gene expression. It also rescued LPS-induced decreases in suppressor of cytokine signaling gene expression, cyclic adenosine monophosphate (cAMP) content, and phosphorylated cAMP response element binding protein expression in the brain.

CONCLUSION

The present study sheds light on the potential neuroprotective effects of alogliptin against intracerebroventricular LPS-induced neuroinflammation and its associated memory impairment via inhibition of toll-like receptor 4/ myeloid differentiation primary response 88/ nuclear factor-κB signaling, modulation of microRNA-155/suppressor of cytokine signaling-1 expression, and enhancement of cAMP/phosphorylated cAMP response element binding protein signaling.

Alleviation of remote lung injury following liver ischemia/reperfusion: Possible protective role of vildagliptin

Lung injury is a serious condition encountered following hepatic ischemia/reperfusion (IR). This study aimed to explore whether a dipeptidyl peptidase-4 inhibitor agent vildagliptin (V) could alleviate the lung injury caused by hepatic IR in a rat model and if so elucidate its molecular protective mechanism. Three groups of rats were used. Sham group: received normal saline and exposed to a sham operation, IR group: received normal saline and subjected to the operation of hepatic I (45 min)/ R (180 min), V+IR group: received for 10 days intraperitoneal injection of V (10 mg/kg/day). After reperfusion, liver and lung were collected for biochemical and histological evaluation. Hepatic IR exhibited significant elevation in serum alanine aminotransferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) enzyme levels, serum and lung malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-α) in addition to lung nitric oxide (NO) levels, hypoxia-inducible factor 1-alpha (HIF-1α) mRNA and protein levels, hepatocyte growth factor (HGF) mRNA expression, and inducible nitric oxide synthase (iNOS) mRNA and protein expressions in lung tissue along with a marked reduction in the serum and lung content of catalase in comparison to the sham group. Moreover, liver and lung injury in the IR group was detected by histopathological examination. Vildagliptin ameliorated markedly the biochemical changes as well as liver and lung architecture in comparison to the IR group. Vildagliptin mitigated the induced lung injury by hepatic IR via suppression of oxidative stress markers, pro-inflammatory cytokine TNF-α as well as the HIF1-α/iNOS/HGF expressions in lung tissue.

Effects of notoginseng leaf triterpenes on small molecule metabolism after cerebral ischemia/reperfusion injury assessed using MALDI-MS imaging

Background

Notoginseng leaf triterpenes (PNGL) is believed to have neuroprotective effects via the inhibition of inflammatory response and neuronal apoptosis. However, its mechanisms underlying the anti-ischemia/reperfusion (I/R) injury effects on the regulation of small molecule metabolism in rat brain remains unclear. The purpose of this study was thus to explore the mechanisms of PNGL on the regulation of small molecule metabolism in rat brain after I/R injury using matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI).

Methods

As a model of in vivo cerebral I/R injury, male Sprague-Dawley (SD) rats were established with a middle cerebral artery occlusion/reperfusion (MCAO/R) model after PNGL administration with 40 mg·kg^-1 through intraperitoneal injection (i.p.) for 7 days. We assessed the neurological behavior, regional cerebral blood flow (r CBF), neuron injury, and spatial distribution of metabolic small molecules.

Results

Our in vivo results suggested that PNGL increased cerebral blood flow and relieved neurological dysfunction. Furthermore, using MALDI-MSI, we demonstrated that PNGL regulated 16 endogenous small molecules implicated in metabolic networks including tricarboxylic acid (TCA) cycle, adenosine triphosphate (ATP) metabolism, malate-aspartate shuttle, metal ions, and antioxidants underwent noticeable changes after reperfusion for 24 h.

Conclusions

PNGL is a novel cerebrovascular agent that can improve cerebral blood flow and attenuate adverse neurological disorders. The mechanisms are closely correlated with relative metabolic pathways, which offers insight into exploring new mechanisms in PNGL for the treatment of cerebral I/R injury.

The effects of meldonium on the acute ischemia/reperfusion liver injury in rats

Acute ischemia/reperfusion (I/R) liver injury is a clinical condition challenging to treat. Meldonium is an anti-ischemic agent that shifts energy production from fatty acid oxidation to less oxygen-consuming glycolysis. Thus, we investigated the effects of a 4-week meldonium pre-treatment (300 mg/kg b.m./day) on the acute I/R liver injury in Wistar strain male rats. Our results showed that meldonium ameliorates I/R-induced liver inflammation and injury, as confirmed by liver histology, and by attenuation of serum alanine- and aspartate aminotransferase activity, serum and liver high mobility group box 1 protein expression, and liver expression of Bax/Bcl2, haptoglobin, and the phosphorylated nuclear factor kappa-light-chain-enhancer of activated B cells. Through the increased hepatic activation of the nuclear factor erythroid 2-related factor 2, meldonium improves the antioxidative defence in the liver of animals subjected to I/R, as proved by an increase in serum and liver ascorbic/dehydroascorbic acid ratio, hepatic haem oxygenase 1 expression, glutathione and free thiol groups content, and hepatic copper-zinc superoxide dismutase, manganese superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activity. Based on our results, it can be concluded that meldonium represent a protective agent against I/R-induced liver injury, with a clinical significance in surgical procedures.

Vildagliptin attenuates acetic acid-induced colitis in rats via targeting PI3K/Akt/NFκB, Nrf2 and CREB signaling pathways and the expression of lncRNA IFNG-AS1 and miR-146a

Inflammatory processes, including ulcerative colitis (UC), are associated with the increase in synthesis and release of pro-inflammatory cytokines. The release of these cytokines is regulated by phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/nuclear factor-kappa B (NFκB) and cAMP response element-binding protein (CREB) signaling pathways as well as over expression of microRNA 146a (miR-146a) and long non-coding RNA interferon gamma antisense 1 (lncRNA IFNG-AS1). Vildagliptin (Vilda), a dipeptidyl peptidase IV (DPP-IV) inhibitor, has an anti-inflammatory, antioxidant and anti-apoptotic effects which were established in various models. However, its possible protective effect in UC has not been clarified. Hence, the current study aimed to explore the possible prophylactic effect of different doses of Vilda against acetic acid (AA)-induced colitis in rats. Forty-eight adult Wistar rats were divided into six groups: control, Vilda (10 mg/kg/day; p.o.), AA, AA + Vilda (5 mg/kg/day; p.o.), AA + Vilda (10 mg/kg/day; p.o.) and AA + sulfasalazine (Sulfa) (100 mg/kg/day; p.o.).Low- and high-dose Vilda showed significant improvement in the disease activity index (DAI) and macroscopic assessment markers. Vilda has markedly inhibited the expression of lncRNA IFNG-AS1 and miR-146a, as well as PI3K/Akt/NFκB pathway, while activated CREB and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways, and this was reflected in alleviated oxidative stress, inflammation and apoptosis. Such outcomes were more prominent with the high-dose Vilda versus low-dose Vilda and Sulfa. Moreover, the histological examination showed almost intact histological features in Vilda-treated groups when compared to AA group treated with saline. In conclusion, Vilda can be regarded as a new promising therapeutic alternative against UC.

Diacerein protects rats with liver ischemia/reperfusion damage: Down-regulation of TLR4/ NFκ-B signaling pathway

PURPOSE

Liver ischemia-reperfusion (I/R) injury is an inescapable problem. Diacerein, a chondro-protective drug, has antioxidant and anti-inflammatory effects. Its effect on liver I/R injury has not yet been fully clarified. Therefore, the current study aimed to detect its hepatic protective effect with the explanation of possible underlying mechanisms.

METHODS

Adult male albino rats were assigned to 4 groups: sham group, diacerein pretreated sham group, I/R non-treated group, and I/R diacerein pretreated group. Serum liver enzymes, hepatic tissue oxidative stress parameters, inflammatory biomarkers mainly Toll-like receptors-4 (TLR4), and liver fatty acid binding protein (L-FABP) levels were determined. Histopathological examination of liver tissues and immunohistochemical studies of heat shock protein 70, nuclear factor-kappa B, and Cluster of Differentiation 68 were also done.

RESULTS

Diacerein pretreatment has the ability to restore the hepatic I/R damaging effect, proved by the reduction of serum liver enzymes, the decrease of the oxidative stress and hepatic inflammation via down-regulation of TLR4/ NFκ-B signaling pathway together with the restoration of L-FABP level and improvement of the histopathological and immunohistochemical study findings in the hepatic tissue.

CONCLUSION

These results suggested the hepatoprotective effect of diacerein relies on its antioxidant and anti-inflammatory effects reducing TLR4/ NFκ-B signaling pathway.

Octreotide and melatonin alleviate inflammasome-induced pyroptosis through inhibition of TLR4-NF-κB-NLRP3 pathway in hepatic ischemia/reperfusion injury

BACKGROUND AND AIM

The Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB)/NLRP3 inflammasome signaling pathway is essential in the pathogenesis of hepatic ischemia/ reperfusion (HIR) injury. Pyroptosis is a proinflammatory programmed cell death that is related to several diseases. Thus, the purpose of this study was to examine whether pretreatment with octreotide (somatostatin analogue, OCT) at different doses or OCT at 75μg/kg combined with melatonin (N-acetyl-5-methoxytryptamine, MLT) can alleviate HIR injury via targeting NLRP3 inflammasome-induced pyroptosis in a TLR4/MyD88/NF-κB dependent manner.

METHODS

Rats were randomized into sham, HIR, OCT (50, 75, and 100 µg/kg), MLT, and MLT + OCT75 groups. Ischemia was induced via occlusion of the portal triad for 30 min followed by 24 h reperfusion.

RESULTS

OCT pretreatment at doses (50 or 75 μg/kg), MLT alone, and MLT + OCT75 significantly ameliorated the biochemical with histopathological changes, oxidative stress, inflammation, apoptosis, then augmented anti-oxidant and anti-apoptotic markers through downregulation of HMGB1, TLR4, MyD88, TRAF-6, p-IκBα (S32), p-NF-κBp65 (S536), NLRP3, ASC, caspase-1(p20), and GSDMD-N expressions compared with HIR group.

CONCLUSION

OCT at doses (50 or 75 µg/kg) showed for the first time a hepatoprotective effect against HIR injury via inhibiting TLR4-NLRP3-mediated pyroptosis in rats. As well, OCT75 was more effective than OCT50 or MLT alone, and its effect was not enhanced after the addition of MLT, through downregulation of TLR4/MyD88/NF-κB/NLRP3 inflammasome pathway.

Renoprotective effect of vildagliptin following hepatic ischemia/reperfusion injury

Remote renal injury is a drastic consequence of hepatic ischemia/reperfusion (IR) injury. Vildagliptin (V) is a dipeptidyl peptidase-4 inhibitor that has a hepatorenal protective effect against models of liver and renal IR. This research was done to explore the protective role of vildagliptin against renal injury following hepatic IR injury as well as the possible involvement of transforming growth factor-beta (TGF-β)/Smad/alpha-smooth muscle actin (α-SMA) expressions in the pathophysiological mechanism of the remote renal injury. Three groups of male Wistar rats were organized into: sham group, IR group, and V + IR group in which 10 mg/kg/day of vildagliptin was pretreated for 10 days intraperitoneally. Blood in addition to renal and hepatic tissue samples was used for biochemical and histopathological studies. Hepatic IR induced a marked increase in serum creatinine, blood urea nitrogen, liver enzymes, renal nitric oxide, malondialdehyde, tumor necrosis factor-alpha levels with a marked upregulation of renal mRNA expressions of TGF-β, Smad2, Smad3, and α-SMA in addition to a marked decline in renal catalase content comparing to the sham group. Abnormal histopathological findings of hepatic and renal injury were detected in the IR group. Vildagliptin significantly improved these biochemical markers as well as the histopathological changes. The upregulation of renal TGF-β/Smad/α-SMA mRNA expressions was involved for the first time in the pathogenesis of the renal injury following hepatic IR and vildagliptin ameliorated this renal injury through blocking these expressions.

Aucubin Attenuates Liver Ischemia-Reperfusion Injury by Inhibiting the HMGB1/TLR-4/NF-κB Signaling Pathway, Oxidative Stress, and Apoptosis

Liver ischemia-reperfusion injury (IRI) is a common clinical event with high morbidity in patients undergoing complex liver surgery or having abdominal trauma. Inflammatory and oxidative stress responses are the main contributing factors in liver IRI. The iridoid glucoside aucubin (AU) has good anti-inflammatory and antioxidative effects; however, there are no relevant reports on the protective effect of glucosides on hepatic IRI. The purpose of this study was to determine whether AU pretreatment could prevent liver IRI and to explore the mechanism. Sprague–Dawley rats were randomly divided into five groups. The sham operation and IRI control groups were given intraperitoneal injections of normal saline, while the AU low-dose (AU-L) group, AU medium-dose (AU-M) group, and AU high-dose (AU-H) group were given intraperitoneal injections of AU at doses of 1, 5, and 10 mg/kg/day, respectively. After 10 d, liver IRI (70% liver ischemia for 1 h, reperfusion for 6 h) was surgically established in all groups except the sham group. Our results confirmed that liver injury was significantly aggravated after hepatic ischemia-reperfusion. AU alleviated the increase of transaminase and pathological changes induced by ischemia-reperfusion and improved liver damage. AU could also ameliorate the inflammatory and oxidative stress responses induced by ischemia-reperfusion and reduced expression of high mobility group protein (HMG)B1, receptor for advanced glycation end-products (RAGE), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and reactive oxygen species (ROS). Moreover, AU reduced ischemia-reperfusion-induced mitochondrial dysfunction and cells apoptosis, increased peroxisome proliferator-activated receptor γ coactivator (PGC)-1α and uncoupling (UCP)2 protein expression, and reduced caspase-3, cleaved caspase-3, and Cytochrome P450 proteins (CYP) expression. To determine expression levels of the Toll-like receptor (TLR)-4/nuclear factor-κB (NF-κB) pathway-related proteins in vitro and in vivo, we also measured TLR-4, myeloid differentiation factor88 (MyD88), NF-κB P65, p-P65, I-kappa-B-alpha (IκB-α), and p-IκB-α levels. The results showed that AU effectively inhibited activation of the TLR-4/NF-κB signaling pathway. In conclusion, we showed for the first time a hepatoprotective effect for AU in liver IRI, which acted by inhibiting the HMGB1/TLR-4/NF-κB signaling pathway, oxidative stress, and apoptosis. Pretreatment with AU may be a promising strategy for preventing liver IRI.

Electroacupuncture pre‑conditioning protects from lung injury induced by limb ischemia/reperfusion through TLR4 and NF‑κB in rats

Limb ischemia/reperfusion (I/R) can induce inflammation, causing acute lung injury. The Toll-like receptor 4 (TLR4)/NF-κB pathway plays an important role in acute and chronic inflammatory disorders. Several studies have demonstrated the efficacy of acupuncture in lung inflammatory injury. The aim of the present study was to elucidate the mechanism underlying the protective effect of electroacupuncture (EA) against lung injury induced by limb I/R. EA applied at the Zusanli and Sanyinjiao acupoints attenuated lung injury and decreased the secretion of inflammatory factors such as tumor necrosis factor-α, interleukin (IL)-1, IL-6 and myeloperoxidase. Moreover, the expression levels of TLR4 and NF-κB were suppressed by EA. Thus, the present findings suggested that EA can reduce pulmonary inflammation induced by limb I/R injury, possibly via the inhibition of the TLR4/NF-κB pathway.

Inhibition of miR-450b-5p ameliorates hepatic ischemia/reperfusion injury via targeting CRYAB

Hepatic ischemia/reperfusion injury (IRI) is an unavoidable course in liver transplantation, during which the immune response of inflammation plays a leading part. MicroRNA-450b-5p (miR-450b-5p), which has been reported to participate in several inflammatory diseases, was investigated in this study. The purpose of this study is to identify the potential function of miR-450b-5p toward remission of hepatic IRI and elucidate the specific mechanism. Herein we found that expression of miR-450b-5p, interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), and IL-6 was stimulated in hepatic IRI. Inhibition of miR-450b-5p could remarkably alleviate mouse hepatic IRI and improve liver function measured by hematoxylin-eosin (HE) staining, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL), and enzyme-linked immunosorbent assay (ELISA). We further assessed protein expression undergoing Western blot and immunofluorescence, and discovered that miR-450b-5p suppressed alpha B-crystallin (CRYAB), thus restraining the inhibitory κB kinase (IKK) β-mediated canonical nuclear factor-κB (NF-κB) signaling, instead of the noncanonical path guided by IKKα in hepatic IRI. In addition, we demonstrated CRYAB as an activator of M2 polarization through protein kinase B (Akt) 1/mammalian target of rapamycin (mTOR), thus resulting in relief of liver IRI. Combination treatment containing both paths revealed a better antidamage efficacy than adjusting either path alone, suggesting that the joint therapy might be a promising solution in hepatic IRI.

Mitigation of renal inflammation and endoplasmic reticulum stress by vildagliptin and statins in high-fat high-fructose diet-induced insulin resistance and renal injury in rats

Dyslipidemia and insulin resistance in obesity can lead to lipotoxicity and cellular damage. Renal lipotoxicity in association with an impairment of lipid metabolism induces renal damage through the activation of inflammation, ER stress, fibrosis and apoptosis. We investigated the effects of a combination treatment of the DPP-4 inhibitor vildagliptin and atorvastatin on renal lipotoxicity related to renal dysfunction and injury in a high-fat high-fructose diet (HFF)-induced insulin resistant condition. Male Wistar rats were fed on a high-fat diet and were given drinking water with 10% fructose for 16 weeks. After that, rats were divided into: no treatment (HFF), treatment with vildagliptin, atorvastatin and vildagliptin plus atorvastatin for 4 weeks. The results demonstrated that the combination treatment prominently improved insulin resistance, dyslipidemia and kidney morphological changes induced by HFF. These changes correlated well with the increased expression of nephrin and podocin and decreased urine protein. Notably, the combined treatment produced greater improvement in renal lipid metabolism through increasing fatty acid oxidation with the decreases in fatty acid transporters and fatty acid synthesis, thereby reducing renal lipid accumulation in HFF rats. The reduction in renal lipotoxicity via diminishing renal inflammation, ER stress, fibrosis and apoptosis was also more significant in the combined treatment group than in the other groups in which the drug was used as a monotherapy. In conclusion, the combination therapy produced synergistic beneficial effects on metabolic parameters, lipid metabolism and accumulation related to renal lipid accumulation-induced lipotoxicity and kidney injury in the HFF-induced insulin resistant model with improved outcomes.

Metformin Attenuates Ischemia-reperfusion Injury of Fatty Liver in Rats Through Inhibition of the TLR4/NF-κB Axis

Background

Donor organs for liver transplantation may often have fatty liver disease, which confers a higher sensitivity to ischemia/reperfusion injury. At present, there is no effective treatment for the condition. Evidence has suggested that metformin, the first-line medication for diabetes, has protective effects against many disorders. However, the potential role of metformin in ischemia/reperfusion injury in fatty liver disease remains unclear.

Aims

To examine the effect of metformin treatment during ischemia/reperfusion injury in fatty liver and determine the possible mechanisms.

Study Design

Animal experimentation.

Methods

Sprague-Dawley male rats were fed a high-fat diet (520 kcal/100 g) for 14 weeks and then were subjected to the orthotopic autologous liver transplantation model. Sections of liver tissue were stained with hematoxylin and eosin to visualize the damage. Blood and liver samples were used to analyze the related proteins and components involved in the inflammatory signaling pathway.

Results

We found that metformin significantly ameliorated the ischemia/reperfusion injury of the fatty liver through a reduction in alanine aminotransferase/aspartate aminotransferase concentrations in the serum and a decrease in dead cells, as shown by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay (p<0.05). In addition, metformin significantly attenuated interleukin (IL)-6, IL-1β, and tumor necrosis factor-α production and increased the expression of active caspase-3 and Bax in the liver (p<0.05). Mechanistically, metformin suppressed the activation of toll-like receptor 4 (TLR4)/NF-κB signaling (p<0.05), resulting in a decreased inflammatory response and apoptosis.

Conclusion

Our findings demonstrated that metformin attenuated ischemia/reperfusion injury in fatty liver disease via the TLR4/NF-κB axis, suggesting that metformin could have potential therapeutic applications in ischemia/reperfusion injury associated with liver transplantation.

Sitagliptin protects male albino rats with testicular ischaemia/reperfusion damage: Modulation of VCAM-1 and VEGF-A

Twisting of the spermatic cord is considered a popular problem in the urological field, which may lead to testicular necrosis and male infertility. Sitagliptin, a glucose-lowering agent, proved to have a vindicatory function in myocardial and renal ischaemia/reperfusion (I/R), but its role in testicular I/R has not yet been studied. The current work investigates its capability to recover the testicular I/R injury with shedding more light on the mechanism of its action. Four groups were used: sham, sham pretreated with sitagliptin, I/R and sitagliptin/I/R-pretreated groups. The outcomes proved that I/R significantly decreased the serum testosterone, with a major increase in oxidative, inflammatory and nitrosative stress, along with a reduction in testicular vascular endothelial growth factor-A level with marked germinal cell apoptosis. However, pretreatment with sitagliptin significantly reversed the profound testicular I/R damaging effects, on the basis of its antioxidant, anti-inflammatory and anti-apoptotic activities with the ability of recuperation of the testicular vascularity.

The Effect of the Chronic Administration of DPP4-Inhibitors on Systemic Oxidative Stress in Rats with Diabetes Type 2

Type 2 diabetes (T2DM) is characterized by well-preserved insulin secretion; however, the surrounding tissue is insensitive to insulin, resulting in increased blood glucose level due to the inability of tissues to convert glucose into energy. As a result of chronic non-regulation of glucose levels and high daily fluctuations in the blood, the micro- and macrovascular complications occur in these patients. Complications develop through two main mechanisms: induction of oxidative stress and innate immunity. In this regard, the aim of this study was to examine the effect of four week administration of DPP4 inhibitors (saxagliptin, sitagliptin and vildagliptin) to the parameters of oxidative stress and antioxidant defense in the group of rats with diabetes type 2 (T2DM). Sixty Wistar albino rats were divided randomly into 5 groups: group I: control healthy group; group II: rats with diabetes type 2; group III: rats with diabetes type 2 treated with 0.6 mg/kg of sitagliptin; group IV: rats with diabetes type 2 treated with 0.45 mg/kg of saxagliptin, group V: rats with diabetes type 2 treated with 9 mg/kg vildagliptin. The rats from experimental groups were fed with a high-fat diet for 4 weeks and after 6–8 h of starvation received one dose of streptozotocin (STZ) intraperitoneally (25 mg/kg body weight) to induce T2DM. Animals with fasting glucose above 7 mmol / L and insulin over 6 mmol / L were included in the study as rats with T2DM. Upon completion of the experiments, the blood was collected from the anesthetized animals and used for sphectrophotometrical determination of parameters of oxidative stress, and antioxidative defense. T2DM induced significant increase in production of reacitve oxygen species (ROS) (superoxide anion radical and hydrogen peroxide), but additional four-week administration of gliptins induced decrease in ROS values. On the other hand, T2DM induced decrease of nitric oxide, superoxide dismutase, catalaze, and reduced gluthation and concomitant therapy with gliptins induced increase of these parametars, suggesting significant antioxidant potential of this group of drugs.

Shuxuening injection protects against myocardial ischemia-reperfusion injury through reducing oxidative stress, inflammation and thrombosis

Background

Shuxuening injection (SXNI) has a good effect on cardiovascular and cerebrovascular diseases. Here, our study aims to investigate whether SXNI have the protective effect on myocardial ischemia-reperfusion injury (MIRI) and elucidate the mechanism of SXNI's cardiac protection.

Methods

In this experiment, the coronary arteries of Sprague-Dawley (SD) rats were ligated for the induction of a MIRI model. TTC staining and haematoxylin-eosin (HE), as well as troponin I (TnI), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), creatine kinase (CK) and CK-MB levels, were used to detect the protective effect of SXNI. In rat cardiac tissue, superoxide dismutase, catalase, glutathione and malondialdehyde (MDA) activities and glucose-regulated protein 78 (GRP78), calreticulin (CRT), CCAAT/enhancer binding protein homologous protein (CHOP) and caspase-12 expression levels were detected. In rat serum, the levels of inflammatory factors, including high-sensitivity C-reactive protein, monocyte chemoattractant protein-1, tumour necrosis factor-α, interleukin-6 (IL-6) and IL-1β, were measured by Elisa. In the rat arterial tissue, Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) expression was measured by western blot. In the rat plasma, ELISA was used to assay the levels of coagulation and plasmin system indicators, including platelet activating factor, endothelin, tissue factor (TF), plasminogen inhibitor, thromboxane B2, plasma fibrinogen.

Results

The results showed that SXNI can reduce the infarct size of myocardial tissue, decrease the myocardial enzyme and TnI levels and decrease the degree of myocardial damage compared with the model group. Additionally, SXNI can increase the activity of antioxidant enzymes, reduce the MDA level and decrease the GRP78, CRT, CHOP and caspase-12 expression levels. SXNI also decreased the levels of inflammatory cytokines in rat serum, lowered the level of procoagulant molecules in plasma and reduced the TLR4/NF-κB expression.

Conclusions

SXNI has protective effect on MIRI mainly by inhibiting oxidative stress and endoplasmic reticulum stress (ERS), thereby regulating TLR4/NF-κB pathway to reduce inflammation, and lowing procoagulant-related factors levels to reduce the risk of thrombosis.

MiR-146a mimic attenuates murine allergic rhinitis by downregulating TLR4/TRAF6/NF-κB pathway

Aim: This study aims to investigate whether microRNA (miR)-146a exerts therapeutic potential to allergic rhinitis (AR). Methods: Female BALB/c mice were randomly divided into the AR and miR-146a groups. miR-146a was administered into the nostril before ovalbumin (OVA) challenge daily on days 21–28. Results: The expression level of miR-146a in AR nasal mucosa was significantly decreased. miR-146a mimic markedly attenuated sneezing and nasal rubbing events, decreased the levels of ovalbumin-specific IgE as well as mastocyte- and basophil-related inflammatory cytokines, reduced inflammatory cells, affected the T-helper 2-released cytokines. Furthermore, miR-146a mimic inhibited the expressions of proteins relevant to Toll-like receptor 4 (TLR4)/TRAF6/NF-κB signaling pathway. Conclusion: The anti-inflammatory effects of miR-146a on AR might exert through the inhibition of the toll-like receptor 4 (TLR4)/TRAF6/NF-κB signaling pathway to some extent.