Fibroblast Growth Factor 21 (FGF21) Protects against High Fat Diet Induced Inflammation and Islet Hyperplasia in Pancreas

Fibroblast growth factor 21 (FGF21) is an important endocrine metabolic regulator expressed in multiple tissues including liver and adipose tissue. Although highest levels of expression are in pancreas, little is known about the function of FGF21 in this tissue. In order to understand the physiology of FGF21 in the pancreas, we analyzed its expression and regulation in both acinar and islet tissues. We found that acinar tissue express 20-fold higher levels than that observed in islets. We also observed that pancreatic FGF21 is nutritionally regulated; a marked reduction in FGF21 expression was noted with fasting while obesity is associated with 3–4 fold higher expression. Acinar and islet cells are targets of FGF21, which when systemically administered, leads to phosphorylation of the downstream target ERK 1/2 in about half of acinar cells and a small subset of islet cells. Chronic, systemic FGF21 infusion down-regulates its own expression in the pancreas. Mice lacking FGF21 develop significant islet hyperplasia and periductal lymphocytic inflammation when fed with a high fat obesogenic diet. Inflammatory infiltrates consist of TCRb+ Thy1+ T lymphocytes with increased levels of Foxp3+ regulatory T cells. Increased levels of inflammatory cells were coupled with elevated expression of cytokines such as TNFα, IFNγ and IL1β. We conclude that FGF21 acts to limit islet hyperplasia and may also prevent pancreatic inflammation.     

Bazhen Decoction Protects against Acetaminophen Induced Acute Liver Injury by Inhibiting Oxidative Stress,Inflammation and Apoptosis in Mice

Bazhen decoction is a widely used traditional Chinese medicinal decoction, but the scientific validation of its therapeutic potential is lacking. The objective of this study was to investigate corresponding anti-oxidative, anti-inflammatory and anti-apoptosis activities of Bazhen decoction, using acetaminophen-treated mice as a model system. A total of 48 mice were divided into four groups. Group I, negative control, treated with vehicle only. Group II, fed with 500 mg/kg/day Bazhen decoction for 10 continuous days. Group III, received a single dose of 900 mg/kg acetaminophen. Group IV, fed with 500 mg/kg/day Bazhen decoction for 10 continuous days and a single dose of 900 mg/kg acetaminophen 30 min before last Bazhen decoction administration. Bazhen decoction administration significantly decrease acetaminophen-induced serum ALT, AST, ALP, LDH, TNF-α, IL-1β, ROS, TBARS and protein carbonyl group levels, as well as GSH depletion and loss of MMP. Bazhen decoction restore SOD, CAT, GR and GPx activities and depress the expression of pro-inflammatory factors, such as iNOS, COX-2, TNF-α, NF-κB, IL-1β and IL-6, respectively. Moreover, Bazhen decoction down-regulate acetaminophen-induced Bax/Bcl-2 ratio, caspase 3, caspase 8 and caspase 9. These results suggest the anti-oxidative, anti-inflammatory and anti-apoptosis properties of Bazhen decoction towards acetaminophen-induced liver injury in mice.     

Baicalein Reduces Airway Injury in Allergen and IL-13 Induced Airway Inflammation

Background

Baicalein, a bioflavone present in the dry roots of Scutellaria baicalensis Georgi, is known to reduce eotaxin production in human fibroblasts. However, there are no reports of its anti-asthma activity or its effect on airway injury.

Methodology/Principal Findings

In a standard experimental asthma model, male Balb/c mice that were sensitized with ovalbumin (OVA), treated with baicalein (10 mg/kg, ip) or a vehicle control, either during (preventive use) or after OVA challenge (therapeutic use). In an alternate model, baicalein was administered to male Balb/c mice which were given either IL-4 or IL-13 intranasally. Features of asthma were determined by estimating airway hyperresponsiveness (AHR), histopathological changes and biochemical assays of key inflammatory molecules. Airway injury was determined with apoptotic assays, transmission electron microscopy and assessing key mitochondrial functions. Baicalein treatment reduced AHR and inflammation in both experimental models. TGF-β₁, sub-epithelial fibrosis and goblet cell metaplasia, were also reduced. Furthermore, baicalein treatment significantly reduced 12/15-LOX activity, features of mitochondrial dysfunctions, and apoptosis of bronchial epithelia.

Conclusion/Significance

Our findings demonstrate that baicalein can attenuate important features of asthma, possibly through the reduction of airway injury and restoration of mitochondrial function.     

Attenuation of Experimental Colitis in Glutathione Peroxidase 1 and Catalase Double Knockout Mice through Enhancing Regulatory T Cell Function

Reactive oxygen species (ROS) have been implicated in the progression of inflammatory diseases including inflammatory bowel diseases (IBD). Meanwhile, several studies suggested the protective role of ROS in immune-mediated inflammatory diseases, and it was recently reported that dextran sodium sulfate (DSS)-induced colitis was attenuated in mice with an elevated level of ROS due to deficiency of peroxiredoxin II. Regulatory T cells (Tregs) are critical in the prevention of IBD and Treg function was reported to be closely associated with ROS level, but it has been investigated only in lowered levels of ROS so far. In the present study, in order to clarify the relationship between ROS level and Treg function, and their role in the pathogenesis of IBD, we investigated mice with an elevated level of ROS due to deficiency of both glutathione peroxidase (GPx)-1 and catalase (Cat) for the susceptibility of DSS-induced colitis in association with Treg function. The results showed that DSS-induced colitis was attenuated and Tregs were hyperfunctional in GPx1^−/− × Cat^−/− mice. In vivo administration of N-acetylcysteine (NAC) aggravated DSS-induced colitis and decreased Treg function to the level comparable to WT mice. Attenuated Th₁₇ cell differentiation from naïve CD4⁺ cells as well as impaired production of IL-6 and IL-17A by splenocytes upon stimulation suggested anti-inflammatory tendency of GPx1^−/− × Cat^−/− mice. Suppression of Stat3 activation in association with enhancement of indoleamine 2,3-dioxygenase and FoxP3 expression might be involved in the immunosuppressive mechanism of GPx1^−/− × Cat^−/− mice. Taken together, it is implied that ROS level is critical in the regulation of Treg function, and IBD may be attenuated in appropriately elevated levels of ROS.     

Mitochondrial Modulation by Epigallocatechin 3-Gallate Ameliorates Cisplatin Induced Renal Injury through Decreasing Oxidative/Nitrative Stress,Inflammation and NF-kB in Mice

Cancer chemotherapy drug cisplatin is known for its nephrotoxicity. The aim of this study is to investigate whether Epigallocatechin 3-Gallate (EGCG) can reduce cisplatin mediated side effect in kidney and to understand its mechanism of protection against tissue injury. We used a well-established 3-day cisplatin induced nephrotoxicity mice model where EGCG were administered. EGCG is a major active compound in Green Tea and have strong anti-oxidant and anti-inflammatory properties. EGCG protected against cisplatin induced renal dysfunction as measured by serum creatinine and blood urea nitrogen (BUN). EGCG improved cisplatin induced kidney structural damages such as tubular dilatation, cast formation, granulovaculoar degeneration and tubular cell necrosis as evident by PAS staining. Cisplatin induced kidney specific mitochondrial oxidative stress, impaired activities of mitochondrial electron transport chain enzyme complexes, impaired anti-oxidant defense enzyme activities such as glutathione peroxidase (GPX) and manganese superoxide dismutase (MnSOD) in mitochondria, inflammation (tumor necrosis factor α and interleukin 1β), increased accumulation of NF-κB in nuclear fraction, p53 induction, and apoptotic cell death (caspase 3 activity and DNA fragmentation). Treatment of mice with EGCG markedly attenuated cisplatin induced mitochondrial oxidative/nitrative stress, mitochondrial damages to electron transport chain activities and antioxidant defense enzyme activities in mitochondria. These mitochondrial modulations by EGCG led to protection mechanism against cisplatin induced inflammation and apoptotic cell death in mice kidney. As a result, EGCG improved renal function in cisplatin mediated kidney damage. In addition to that, EGCG attenuated cisplatin induced apoptotic cell death and mitochondrial reactive oxygen species (ROS) generation in human kidney tubular cell line HK-2. Thus, our data suggest that EGCG may represent new promising adjunct candidate for cisplatin.     

Role of Toll-Like Receptors 2 and 4 in Pulmonary Inflammation and Injury Induced by Pneumolysin in Mice

Background

Pneumolysin (PLN) is an intracellular toxin of Streptococcus pneumoniae that has been implicated as a major virulence factor in infections caused by this pathogen. Conserved bacterial motifs are recognized by the immune system by pattern recognition receptors among which the family of Toll-like receptors (TLRs) prominently features. The primary objective of the present study was to determine the role of TLR2 and TLR4 in lung inflammation induced by intrapulmonary delivery of PLN.

Methodology/Results

First, we confirmed that purified PLN activates cells via TLR4 (not via TLR2) in vitro, using human embryonic kidney cells transfected with either TLR2 or TLR4. Intranasal administration of PLN induced an inflammatory response in the pulmonary compartment of mice in vivo, as reflected by influx of neutrophils, release of proinflammatory cytokines and chemokines, and a rise in total protein concentrations in bronchoalveolar lavage fluid. These PLN-induced responses were dependent in part, not only on TLR4, but also on TLR2, as indicated by studies using TLR deficient mice.

Conclusion

These data suggest that although purified PLN is recognized by TLR4 in vitro, PLN elicits lung inflammation in vivo by mechanisms that may involve multiple TLRs.     

Mice Brain Tissue Injury Induced by Diisononyl Phthalate Exposure and the Protective Application of Vitamin E

As a widely used plasticizer in plastic industry, the data of diisononyl phthalate (DINP) toxicity due to exposure are insufficient. This work investigated the brain tissue injury induced by DINP exposure. Through oral exposure to DINP, oxidative stress, inflammatory responses, apoptosis, and hippocampus pathological alterations were found in the mice brain. And through the Morris water maze test, cognitive deficits were tested. Our data also showed that these exacerbations were counteracted by vitamin E. These results above indicated that oral exposure of mice to DINP induced brain damage, and oxidative stress, inflammation, and the consequential apoptosis jointly constituted the potential mechanisms of such induced toxicity.     

Nebulized Fibrinolytic Agents Improve Pulmonary Fibrinolysis but Not Inflammation in Rat Models of Direct and Indirect Acute Lung Injury

Background

Critically ill patients frequently develop acute lung injury (ALI). Disturbed alveolar fibrin turnover, a characteristic feature of ALI, is the result of both activation of coagulation and inhibition of fibrinolysis. Nebulized fibrinolytic agents could exert lung–protective effects, via promotion of fibrinolysis as well as anti–inflammation.

Methods

Rats were challenged intratracheally with Pseudomonas aeruginosa, resulting in pneumonia as a model for direct ALI, or received an intravenous bolus infusion of lipopolysaccharide, as a model for indirect ALI. Rats were randomized to nebulization of normal saline (placebo), recombinant tissue plasminogen activator (rtPA), or monoclonal antibodies against plasminogen activator inhibitor–type 1 (anti–PAI–1).

Results

Nebulized rtPA or anti–PA1–1 enhanced the bronchoalveolar fibrinolytic system, as reflected by a significant reduction of PAI–1 activity levels in bronchoalveolar lavage fluid, and a consequent increase in plasminogen activator activity (PAA) levels to supranormal values. Both treatments also significantly affected systemic fibrinolysis as reflected by a significant increase in PAA levels in plasma to supranormal levels. Neither nebulized rtPA nor anti–PA1–1 affected pulmonary inflammation. Neither treatment affected bacterial clearance of P. aeruginosa from the lungs in case of pneumonia.

Conclusions

Local treatment with rtPA or anti–PA1–1 affects pulmonary fibrinolysis but not inflammation in models of direct or indirect ALI in rats.     

Dexmedetomidine Protects against Transient Global Cerebral Ischemia/Reperfusion Induced Oxidative Stress and Inflammation in Diabetic Rats

Background

Transient global cerebral ischemia/reperfusion (I/R) is a major perioperative complication, and diabetes increases the response of oxidative stress and inflammation induced by I/R. The objective of this study was to determine the protective effect of dexmedetomidine against transient global cerebral ischemia/reperfusion induced oxidative stress and inflammation in diabetic rats.

Methods

Sixty-four rats were assigned into four experimental groups: normoglycemia, normoglycemia + dexmedetomidine, hyperglycemia, and hyperglycemia + dexmedetomidine and all subsequent neurological examinations were evaluated by a blinded observer. Damage to the brain was histologically assessed using the TUNEL staining method while western blotting was used to investigate changes in the expression levels of apoptosis-related proteins as well as the microglia marker, ionized calcium-binding adapter molecule 1 (Iba1). Water content in the brain was also analyzed. In addition, hippocampal concentrations of malondialdehyde (MDA) and Nox2 (a member of the Nox family of NADPH oxidases), and the activity of superoxide dismutase and catalase were analyzed. Finally, changes in serum concentrations of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 were detected.

Results

Results showed that diabetes increased brain water content, the number of apoptotic neurons, early neurological deficit scores, oxidative stress (MDA and Nox2) and inflammation (pro-inflammatory cytokines including TNF-α and IL-6) levels following transient global I/R injury, but that these symptoms were attenuated following administration of dexmedetomidine.

Conclusions

These findings suggest that dexmedetomidine can significantly alleviate damage resulting from I/R, and this mechanism may be related to a reduction in both oxidative stress and inflammation which is normally associated with I/R.     

Enhanced Neuroprotection of Minimally Invasive Surgery Joint Local Cooling Lavage against ICH-induced Inflammation Injury and Apoptosis in Rats

Hypothermia treatment is one of the neuroprotective strategies that improve neurological outcomes effectively after brain damage. Minimally invasive surgery (MIS) has been an important treatment of intracerebral hemorrhage (ICH). Herein, we evaluated the neuroprotective effect and mechanism of MIS joint local cooling lavage (LCL) treatment on ICH via detecting the inflammatory responses, oxidative injury, and neuronal apoptosis around the hematoma cavity in rats. ICH model was established by type IV collagenase caudatum infusion. The rats were treated with MIS 6 h after injection, and then were lavaged by normothermic (37 °C) and hypothermic (33 °C) normal saline in brain separately. The results indicated that MIS joint LCL treatment showed enhanced therapeutic effects against ICH-induced inflammation injury and apoptosis in rats, as convinced by the decline of TUNEL-positive cells, followed by the decrease of IL-1β and LDH and increase of IL-10 and SOD. This study demonstrated that the strategy of using MIS joint LCL may achieve enhanced neuroprotection against ICH-induced inflammation injury and apoptosis in rats with potential clinic application.     

Epigallocatechin 3-Gallate Ameliorates Bile Duct Ligation Induced Liver Injury in Mice by Modulation of Mitochondrial Oxidative Stress and Inflammation

Cholestatic liver fibrosis was achieved by bile duct ligation (BDL) in mice. Liver injury associated with BDL for 15 days included significant reactive oxygen/nitrogen species generation, liver inflammation, cell death and fibrosis. Administration of Epigallocatechin 3-Gallate (EGCG) in animals reduced liver fibrosis involving parenchymal cells in BDL model. EGCG attenuated BDL-induced gene expression of pro-fibrotic markers (Collagen, Fibronectin, alpha 2 smooth muscle actin or SMA and connective tissue growth factor or CTGF), mitochondrial oxidative stress, cell death marker (DNA fragmentation and PARP activity), NFκB activity and pro-inflammatory cytokines (TNFα, MIP1α, IL1β, and MIP2). EGCG also improved BDL induced damages of mitochondrial electron transport chain complexes and antioxidant defense enzymes such as glutathione peroxidase and manganese superoxide dismutase. EGCG also attenuated hydrogen peroxide induced cell death in hepatocytes in vitro and alleviate stellate cells mediated fibrosis through TIMP1, SMA, Collagen 1 and Fibronectin in vitro. In conclusion, the reactive oxygen/nitrogen species generated from mitochondria plays critical pathogenetic role in the progression of liver inflammation and fibrosis and this study indicate that EGCG might be beneficial for reducing liver inflammation and fibrosis.     

姜黄素预处理通过保护线粒体和抗氧化应激减轻干热环境热射病大鼠肝损伤

目的:研究姜黄素预处理对干热环境热射病大鼠肝脏的保护作用及机制。方法:将50只SD大鼠随机分为5组(n=10):常温对照组(Control),干热对照组(HS),50-cur组,100-cur组和200-cur组。Control组、HS组给予生理盐水灌胃,50-cur组、100-cur组、200-cur组分别给予50 mg/kg、100 mg/kg、200 mg/kg浓度的姜黄素灌胃,每天1次,连续7天。第8天除Control组外,其余4组大鼠转移至西北特殊环境人工实验舱(环境温度41±0.5℃,湿度10±1%)进行实验。实验的第150分钟,检测肛温,麻醉后取材。同时Control组直接检测肛温并麻醉取材。检测血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、肝组织丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的含量和细胞色素C(Cyt-c)的表达情况。电镜观察肝细胞超微结构的变化。结果:(1)第150分钟,各组大鼠体温均超过42℃,达到热射病状态。姜黄素预处理组体温较HS组降低(P0.01)。姜黄素预处理组组间差异无统计学意义(P0.05)。(2)HS组ALT、AST水平较Control组升高(P0.01)。姜黄素预处理组ALT、AST水平较HS组降低(P0.05),姜黄素预处理组组间差异有统计学意义(P0.05)。(3)HS组与Control组相比MDA水平升高,SOD、CAT水平降低(P0.01)。姜黄素预处理组与HS组相比MDA水平降低,SOD、CAT水平升高(P0.01),姜黄素预处理组组间差异有统计学意义(P0.05)。(4)电镜下,HS组肝细胞内线粒体增生肿胀,嵴结构紊乱、破坏,部分肝细胞核结构破坏;姜黄素预处理组肝细胞内线粒体增生为主,无嵴结构破坏和胞核的改变。(5)HS组肝细胞质内Cyt-c表达(1.29±0.19)较Control组(0.24±0.02)明显增多(P0.01)。姜黄素预处理组Cyt-c表达(50-cur、100-cur、200-cur分别为0.75±0.08、0.64±0.08、0.48±0.06)较HS组相对减低(P0.05),姜黄素预处理组组间差异有统计学意义(P0.05)。结论:干热环境热射病大鼠肝脏损伤明显,姜黄素预处理能减轻干热环境热射病导致的肝损伤,其机制可能与保护线粒体和抗氧化应激有关。姜黄素对热射病大鼠肝脏的保护作用具有剂量依赖性。     

Morin Hydrate Mitigates Cisplatin‐Induced Renal and Hepatic Injury by Impeding Oxidative/Nitrosative Stress and Inflammation in Mice

Cisplatin is a widely used chemotherapeutic drug; however, it induces damage on kidney and liver at clinically effective higher doses. Morin hydrate possesses antioxidant, anti‐inflammatory, and anticancer properties. Therefore, we aimed to investigate the effects of morin hydrate (50 and 100 mg/kg, orally) against the renohepatic toxicity induced by a high dose of cisplatin (20 mg/kg, intraperitoneally). Renal and hepatic function, oxidative/nitrosative stress, and inflammatory markers along with histopathology were evaluated. Morin hydrate ameliorated cisplatin‐induced renohepatic toxicity significantly at 100 mg/kg as evidenced from the significant reversal of cisplatin‐induced body weight loss, mortality, functional and structural alterations of kidney, and liver. The protective role offered by morin hydrate against cisplatin‐induced renohepatic toxicity is by virtue of its free radical scavenging property, thereby abating the depletion of cellular antioxidant defense components and through modulation of inflammatory cytokines. We speculate morin hydrate as a protective candidate against renohepatic toxicity of cisplatin.     

MicroRNA-21 mediates the protective role of emulsified isoflurane against myocardial ischemia/reperfusion injury in mice by targeting SPP1

Isoflurane has demonstrated to exert protective impacts against ischemia/reperfusion (I/R) injury in some organs. This research explored the role of emulsified isoflurane (EI) in myocardial I/R injury through the interaction with microRNA-21 (miR-21). The myocardial I/R injury mouse models established by coronary artery ligation were respectively treated with EI, miR-21 mimic/inhibitor or silenced secreted phosphoprotein 1 (SPP1) plasmids. Then, the pathology, fibrosis and cardiomyocyte apoptosis in mouse myocardial tissues were observed. Furthermore, the expression levels of miR-21, SPP1, oxidative stress indices, inflammatory factors and apoptotic proteins in mouse myocardial tissues were determined. The targeting relation between miR-21 and SPP1 was confirmed. MiR-21 was poorly expressed and SPP1 was highly expressed in myocardial I/R injury mice. EI treatment, elevated miR-21, or silenced SPP1 improved cardiac function and suppressed the oxidative stress, myocardial fibrosis, inflammatory reaction and cardiomyocyte apoptosis in myocardial I/R injury mice, thereby reliving the myocardial I/R injury. These therapeutic effects of EI were repressed by miR-21 inhibition. Additionally, SPP1 was targeted by miR-21. Results in our research indicated that miR-21 mediated the therapeutic effect of EI on myocardial I/R injury in mice by targeting SPP1. This study may provide a novel treatment strategy for myocardial I/R injury.