The vitamin D analogue paricalcitol attenuates hepatic ischemia/reperfusion injury through down-regulation of Toll-like receptor 4 signaling in rats

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.

Ghrelin attenuates inflammation in diabetic lung disease by TLR4 pathway in vivo and in vitro

INTRODUCTION

Diabetic lung disease is already known as one of the diabetes complications, but report on its therapeutic strategy is rare. The present study aimed to add novel therapeutic strategy for diabetic lung disease, to reveal the protective effect of ghrelin on diabetic lung disease both in vivo and in vitro, and to discuss its probable molecular mechanism.

RESEARCH DESIGN AND METHODS

Diabetic mice and 16HBE cells were our research objects. We surveyed the effect of ghrelin on streptozotocin-induced lung tissue morphology changes by H&E staining. Furthermore, the changes of proinflammatory cytokines (interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α)) were detected by ELISA. To expound the molecular mechanism, we detected critical proteins of TLR4 pathway and observed their changes by immunohistochemistry (IHC), real-time PCR and western blot analysis in vivo and in vitro, respectively.

RESULTS

The results of H&E staining showed that pathological alterations of the lung induced by hyperglycemia were ameliorated by ghrelin. The results of ELISA demonstrated that the elevated levels of IL-1β and TNF-α induced by hyperglycemia turned to decrease in the lung after ghrelin treatment. In the results of IHC, real-time PCR and western blot analysis, we found that the TLR4 pathway was elevated by hyperglycemia or high glucose and is remarkably inhibited by the treatment of ghrelin both in vivo and in vitro.

CONCLUSIONS

Ghrelin could inhibit inflammation of diabetic lung disease by regulating the TLR4 pathway. This study might affect research on diabetic lung disease, and the therapeutic potential of ghrelin for diabetic lung disease is worth considering.

Calcitriol modulate post-ischemic TLR signaling pathway in ischemic stroke patients

BACKGROUND

Neuroinflammation is a significant contributor to post-ischemic neuronal death after stroke, and Toll-Like Receptors (TLRs) are one of the essential mediators in many inflammatory pathways. TLRs activate the nuclear factor kappa β (NF-kβ), which promotes the expression of various pro-inflammatory genes such as interleukin (IL-1β) and IL-6. 1,25(OH)2D3, also known as calcitriol, is an active form of vitamin D3 that acts as a neurosteroid compound with anti-inflammatory properties. This study aimed to determine the modulatory effects of calcitriol hormone on post-ischemic immunity response.

METHODS

Neurological tests and conventional blood factors were evaluated in patients with stroke symptoms upon arrival (n = 38) to confirm the stroke. A blood sample was taken from each stroke patient immediately upon admission and again after 24 h. The experimental group was given 10 μg calcitriol orally. The gene expression levels of TLR4, TLR2, NF-kβ, IL-1β, and IL-6 pro-inflammatory factors were measured using real-time PCR. The protein expression of TLR4 and NF-kβ markers was assessed using the flow cytometry technique.

RESULTS

TLR4, NF-kβ, and pro-inflammatory factors IL-1β and IL-6 expression increased significantly after an ischemic stroke, and calcitriol could modulate the TLR4/NF-kβ signaling pathway 24 h after ischemia.

CONCLUSIONS

Calcitriol may be considered a protective reagent after ischemia by reducing the TLR4/NF-kB activation cascade and probably plays a beneficial role in reducing and improving ischemic stroke patients' symptoms.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials identifier: IRCT2017012532174N1.

Protective effect of pinocembrin from Penthorum chinense Pursh on hepatic ischemia reperfusion injury via regulating HMGB1/TLR4 signal pathway

Hepatic ischemia-reperfusion injury (HIRI) is of common occurrence during liver surgery and transplantation. Pinocembrin (PIN) is a kind of flavonoid monomer extracted from the local traditional Chinese medicine Penthorum chinense Pursh (P. chinense). However, the effect of PIN on HIRI has not determined. We investigated the protective effect and potential mechanism of PIN against HIRI. Model mice were subjected to partial liver ischemia for 60 min, experimental mice were pretreated with PIN orally for 7 days, and H₂ O₂ -induced oxidative damage model in AML12 hepatic cells was established in vitro. Histopathologic analysis and serum biochemical levels revealed that PIN had hepatoprotective activities against HIRI. The variation of GSH, SOD, MDA, and ROS levels indicated that PIN treatments attenuated oxidative stress in tissue. PIN pretreatment obviously ameliorated apoptosis, and restrained the expression of HMGB1 and TLR4 in vivo. In vitro, compared with H₂ O₂ group, the contents of ROS, mitochondrial membrane potential, apoptotic cells, and Bcl-2 protein were decreased, while the Bax protein expression was increased. Moreover, HMGB-1 small interfering RNA test and western blotting showed that PIN pretreatment reduced HMGB1 and TLR4 protein levels. In conclusion, PIN pretreatment effectively protected hepatocytes from HIRI and inhibited the HMGB1/TLR4 signaling pathway.

Vitamin D Receptor Regulates Autophagy to Inhibit Apoptosis and Promote Proliferation in Hepatocyte Injury

BACKGROUND

Oxidative stress is an important mechanism in liver ischemia/reperfusion (I/R) injury. Hepatocyte apoptosis and proliferation occur in parallel with liver I/R injury, and the degree of apoptosis and proliferation determines the effects on hepatocytes. Vitamin D receptor (VDR) can lessen liver I/R injury, but previous studies focused mostly on inflammation and immunity.

METHODS

H₂O₂ was used to induce hepatocyte injury. Before treatment with H₂O₂, Hep-3B cells were pretreated with paricalcitol (PC) and siRNA-VDR. Rapamycin and chloroquine were also applied in the study.

RESULTS

The number of apoptotic cells was measured with an annexin V (AV) -fluorescein isothiocyanate apoptosis detection kit. Expression of proteins was measured by western blotting. As compared with the H₂O₂+Hep-3B group, levels of AV/PI, cleaved caspase-3, and p62 were lower, and expression levels of Bcl-2, proliferating cell nuclear antigen, and VDR were higher, in the PC+H₂O₂+Hep-3B group. When the VDR gene was silenced by siRNA-VDR in the siRNA-VDR+H₂O₂+Hep-3B group, expressions of AV/PI, cleaved caspase-3, and p62 were upregulated, and expressions of Bcl-2, proliferating cell nuclear antigen, and VDR were downregulated, as compared with values for the siRNA-NC+H₂O₂+Hep-3B group. Treatment with rapamycin or chloroquine partially reversed the effect of PC and siRNA-VDR on apoptosis and proliferation.

CONCLUSIONS

VDR mediates hepatocyte apoptosis and proliferation through autophagy.

Salidroside alleviates hepatic ischemia-reperfusion injury during liver transplant in rat through regulating TLR-4/NF-κB/NLRP3 inflammatory pathway

Salidroside has anti-inflammatory, antioxidant and hepatoprotective properties. However, its effect on hepatic ischemia–reperfusion injury (IRI), an unavoidable side effect associated with liver transplantation, remains undefined. Here, we aimed to determine whether salidroside alleviates hepatic IRI and elucidate its potential mechanisms. We used both in vivo and in vitro assays to assess the effect and mechanisms of salidroside on hepatic IRI. Hepatic IRI rat models were pretreated with salidroside (5, 10 or 20 mg/kg/day) for 7 days following liver transplantation while hypoxia/reoxygenation (H/R) model of RAW 264.7 macrophages were pretreated with salidroside (1, 10 or 50 μM). The effect of salidroside on hepatic IRI was assessed using hematoxylin–eosin staining, terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, qRT-PCR, immunosorbent assay and western blotting. Our in vivo assays showed that salidroside significantly reduced pathological liver damage, serum aminotransferase levels and serum levels of IL-1, IL-18 and TNF-α. Besides, salidroside reduced the expression of TLR-4/NF-κB/NLRP3 inflammatory pathway associated proteins (TLR-4, MyD88, p-IKKα, p-IKKβ, p-IKK, p-IκBα, p-P65, NLRP3, ASC, Cleaved caspase-1, IL-1β, IL-18, TNF-α and IL-6) in rats after liver transplantation. On the other hand, data from the in vitro analysis demonstrated that salidroside blocks expression of TLR-4/NF-κB/NLRP3 inflammatory pathway related proteins in the RAW264.7 cells treated with H/R. The salidroside-specific anti-inflammatory effects were partially inhibited by the TLR-4 agonist lipopolysaccharide. Taken together, our study showed that salidroside inhibits hepatic IRI following liver transplantation by modulating the TLR-4/NF-κB/NLRP3 inflammatory pathway.

Therapeutic effect of acute and chronic use of different doses of vitamin D3 on seizure responses and cognitive impairments induced by pentylenetetrazole in immature male rats

Objective(s):

This study aimed to evaluate the effects of acute and chronic intake of different doses of vitamin D3 on seizure responses and cognitive impairment induced by pentylenetetrazole (PTZ) in immature male rats.

Materials and Methods:

Sixty-six immature male NMRI rats were divided into control (10), epileptic (10), and treatment groups (46). The stage 5 latency (S5L) and stage 5 duration (S5D) were assessed along with the shuttle box test. Levels of antioxidant enzymes and inflammatory factors along with genes involved in inflammation, oxidative damage, apoptosis, and mTORc1 were measured in the hippocampus tissue of the brain of controlled and treated rats. Serum levels of parathyroid hormone (PTH), vitamin D, calcium, and phosphorus were also assessed.

Results:

The results showed that the ability to learn, memory consolidation, and memory retention in epileptic rats were reduced. In addition, S5D increased and S5L decreased in epileptic rats, while being effectively ameliorated by chronic and acute vitamin D intake. The results showed that vitamin D in different doses acutely and chronically decreased the levels of oxidative and inflammatory biomarkers in hippocampus tissue and inhibited the expression of genes involved in inflammation, oxidative damage, apoptosis, and mTORc1 in the hippocampus tissue of epileptic rats.

Conclusion:

The results showed that vitamin D in different doses acutely and chronically could improve cognitive impairments and convulsive responses in epileptic rats by improving neurotransmission, inflammation, apoptosis, and oxidative damage.

HMGB1: An overview of its roles in the pathogenesis of liver disease

High-mobility group box 1 (HMGB1) is an abundant architectural chromosomal protein that has multiple biologic functions: gene transcription, DNA replication, DNA-damage repair, and cell signaling for inflammation. HMGB1 can be released passively by necrotic cells or secreted actively by activated immune cells into the extracellular milieu after injury. Extracellular HMGB1 acts as a damage-associated molecular pattern to initiate the innate inflammatory response to infection and injury by communicating with neighboring cells through binding to specific cell-surface receptors, including Toll-like receptors (TLRs) and the receptor for advanced glycation end products (RAGE). Numerous studies have suggested HMGB1 to act as a key protein mediating the pathogenesis of chronic and acute liver diseases, including nonalcoholic fatty liver disease, hepatocellular carcinoma, and hepatic ischemia/reperfusion injury. Here, we provide a detailed review that focuses on the role of HMGB1 and HMGB1-mediated inflammatory signaling pathways in the pathogenesis of liver diseases.

Is there a relation between vitamin D, interleukin-17, and bone mineral density in patients with inflammatory bowel disease?

INTRODUCTION

In inflammatory bowel diseases (IBD), osteopenia and osteoporosis constitute a significant medical problem. Cytokines, especially IL-17, play an important role in the pathogenesis of IBD and osteoporosis. Vitamin D is a regulator of bone metabolism, and helps maintain immune system homeostasis.

MATERIAL AND METHODS

The research sample consisted of 208 persons: 83 patients (age 35 ±11.99 years) with Crohn's disease (CD); 86 patients (age 39.58 ±14.74 years) with ulcerative colitis (UC); and 39 persons (age 30.74 ±8.63 years) in the control group (CG). Clinical data on bone mineral density of the lumbar spine (L2-L4), bone mineral density of the femoral neck (FN), and body mass index (BMI) were collected. 25OHD and IL-17 serum concentrations were also measured.

RESULTS

Body mass index (kg/m²) results: in CD, 21.51 ±3.68; in UC, 23.31 ±4.38; and in CG, 24.57 ±3.45 (p < 0.01). Densitometry results for L2-L4 T-score SD: in CD -0.83 ±1.45; in UC -0.47 ±1.15; in CG 0.09 ±0.70. Densitometry results for FN T-score SD: in CD -0.62 ±1.26; in UC -0.29±1.17; in CG 0.41 ±1.03 25OHD (ng/ml) serum concentrations: in CD, 21.33±12.50; in UC, 22.04±9.56; in CG, 21.56±9.11 (ns). IL-17 (pg/ml) serum concentrations: in CD, 8.55±10.99; in UC, 11.67±12.97; in CG, 5.16±9.11 (ns).

CONCLUSIONS

Inflammatory bowel diseases patients and persons from the CG did not differ in vitamin D or IL-17 levels. Patients with a mild course of the disease had a higher vitamin D concentration and bone mineral density. In UC, higher vitamin D concentrations were associated with lower IL-17 concentrations. The IBD patients with a severe course of the disease had a lower body mass than those in the CG and the patients with a mild course of the disease.

The role of NF-κB and Smac/DIABLO proteins in the treatment response and survival of acute myeloid leukemia patients

INTRODUCTION

The misbalance between a family of inhibitor of apoptosis proteins (IAP), regulated by the nuclear factor kappa B (NF-κB) and their natural antagonist second mitochondrial-derived activator of caspases/direct IAP binding protein with low pI (Smac/DIABLO) are important to biology of acute myeloid leukemia (AML).

MATERIAL AND METHODS

The aim of the study was to assess NF-κB and Smac/DIABLO proteins expression in blasts of 109 newly diagnosed AML patients using the multicolor flow cytometry and evaluate their influence on AML patients outcome.

RESULTS

Expression of NF-κB and of Smac/DIABLO proteins were found in 95% and 98% of the patients, respectively. A negative correlation between Smac/DIABLO and NF-κB was observed. Age < 60 years old as well as higher Smac/DIABLO expression were associated with a higher probability of complete response achievement in the multivariate analysis. Longer overall survival (OS) in the univariate and multivariate analyses was influenced by age < 60 years old, a favorable or intermediate-risk karyotype and high Smac/DIABLO expression. Additionally, in the survival analysis of the subgroups, the patients aged < 60 years old, with high Smac/DIABLO expression, lower NF-κB expression and < 50% of bone marrow blasts who were treated with standard treatment had better OS.

CONCLUSIONS

Lower NF-κB and higher Smac/DIABLO expression may influence AML patients outcome.

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.

Neuroprotective effect of paricalcitol in a rat model of transient global cerebral ischemia

Background

Paricalcitol is known to attenuate ischemic-reperfusion injury of various organs. However, it is not known whether paricalcitol prevents neuronal injury after global cerebral ischemia. The purpose of this study is to investigate the neuroprotective effect of paricalcitol in a rat model of transient global cerebral ischemia.

Methods

This is a prospective, randomized experimental study. Male Sprague-Dawley rats that survived 10 min of four-vessel occlusion were randomly assigned to two treatment groups: one group was treated with paricalcitol 1 μg/kg IP, and the other was given an equivalent volume of normal saline IP. Drugs were administered at 5 min, 1 day, 2 days, and 3 days after ischemia. Neurologic function was assessed at 2 h, 1 day, 2 days, 3 days, and 4 days after ischemia. We tested motor function 3 days after ischemia using the rotarod test. Also, we tested memory function 4 days after ischemia using the passive avoidance test. We assessed neuronal degeneration in the hippocampus of surviving rats 4 days after ischemia.

Results

Eight rats were allocated to each group. No significant differences were found between the groups in terms of survival rate, motor coordination, or memory function. The neurological function score 2-h post-ischemia was significantly higher in the paricalcitol group (p = 0.04). Neuronal degeneration was significantly less in the paricalcitol group compared with the control group (p = 0.01).

Conclusions

Paricalcitol significantly attenuated neuronal injury in the hippocampus. Although motor coordination, memory function, and survival rate were not significantly improved by paricalcitol treatment in this study, paricalcitol remains a potential neuroprotective drug after global cerebral ischemia.

Paricalcitol accelerates BACE1 lysosomal degradation and inhibits calpain-1 dependent neuronal loss in APP/PS1 transgenic mice

BACKGROUND

Recent studies have revealed that vitamin D deficiency may increase the risk of Alzheimer's disease, and vitamin D supplementation may be effective strategy to ameliorate the neurodegenerative process in Alzheimer's disease patients. Paricalcitol (PAL), a low-calcemic vitamin D receptor agonist, is clinically used to treat secondary hyperparathyroidism. However, the potential application of PAL for treating neurodegenerative disorders remains unexplored.

METHODS

The APP/PS1 mice were intraperitoneally injected with PAL or vehicle every other day for 15 weeks. The β-amyloid (Aβ) production was confirmed using immunostaining and enzyme linked immunosorbent assay. The underlying mechanism was verified by western blot and immunostaining in vivo and in vitro.

FINDINGS

Long-term PAL treatment clearly reduced β-amyloid (Aβ) generation and neuronal loss in APP/PS1 transgenic mouse brains. PAL stimulated the expression of low-density lipoprotein receptor-related protein 1 (LRP1) possibly through inhibiting sterol regulatory element binding protein-2 (SREBP2); PAL also promoted LRP1-mediated β-site APP cleavage enzyme 1 (BACE1) transport to late endosomes, thus increasing the lysosomal degradation of BACE1. Furthermore, PAL diminished 8-hydroxyguanosine (8-OHdG) generation in neuronal mitochondria via enhancing base excision repair (BER), resulting in the attenuation of calpain-1-mediated neuronal loss.

INTERPRETATION

The present data demonstrate that PAL can reduce Aβ generation through accelerating BACE1 lysosomal degradation and can inhibit neuronal loss through suppressing mitochondrial 8-OHdG generation. Hence, PAL might be a promising agent for treating Alzheimer's disease. FUND: This study was financially supported by the Natural Science Foundation of China (U1608282).

Histopathological and biochemical assessment of liver damage in albino Wistar rats treated with cytotoxic platinum compounds in combination with 5-fluorouracil

INTRODUCTION

Chemotherapy-induced hepatotoxicity in cancer patients often results in cessation of therapy and prevents completion of the treatment plan. The entire pathological description and comparison of hepatic damage induced by oxaliplatin or cisplatin in combination with 5-fluorouracil (5-FU) is not adequately reported. This study reports histopathological assessment of hepatotoxicity of a non-tumor bearing organ in rats treated with 5-FU, oxaliplatin and cisplatin (CDDP).

MATERIAL AND METHODS

Changes in hepatic biochemical profile of 36 albino Wistar rats equally divided into different treatment groups with cisplatin, oxaliplatin, 5-FU, cisplatin plus 5-FU and oxaliplatin plus 5-FU were compared with a group of rats treated with normal saline (control group). At the end of treatments, hepatic tissues were taken for blinded histopathological assessment by light microscopy.

RESULTS

Serum glutamate pyruvate transaminase and serum glutamic-oxaloacetic transaminase levels were disrupted in rats treated with 5-FU alone and in combination with cisplatin or oxaliplatin. Hepatocellular injuries, e.g. sinusoidal dilatation, venular fibrosis and centrilobular vein injury induced by oxaliplatin were intensified in treatment groups also receiving 5-FU, manifested as massive architectural distortion, periportal fibrosis, hepatic cord degeneration and cystic lesions with demarcated margins. Hepatocellular degenerative sequence and abnormally dilated central hepatic vein was shown in the cisplatin plus 5-FU treatment group with hemorrhage and blood filled sinusoids.

CONCLUSIONS

Oxaliplatin-associated cystic lesions were intensified in rats treated with a combination of 5-FU and oxaliplatin.

High-Mobility Group Box-1 and Liver Disease

High‐mobility group box‐1 (HMGB1) is a ubiquitous protein. While initially thought to be simply an architectural protein due to its DNA‐binding ability, evidence from the last decade suggests that HMGB1 is a key protein participating in the pathogenesis of acute liver injury and chronic liver disease. When it is passively released or actively secreted after injury, HMGB1 acts as a damage‐associated molecular pattern that communicates injury and inflammation to neighboring cells by the receptor for advanced glycation end products or toll‐like receptor 4, among others. In the setting of acute liver injury, HMGB1 participates in ischemia/reperfusion, sepsis, and drug‐induced liver injury. In the context of chronic liver disease, it has been implicated in alcoholic liver disease, liver fibrosis, nonalcoholic steatohepatitis, and hepatocellular carcinoma. Recently, specific posttranslational modifications have been identified that could condition the effects of the protein in the liver. Here, we provide a detailed review of how HMGB1 signaling participates in acute liver injury and chronic liver disease.

MicroRNA-135b-5p prevents oxygen-glucose deprivation and reoxygenation-induced neuronal injury through regulation of the GSK-3β/Nrf2/ARE signaling pathway

INTRODUCTION

MicroRNAs (miRNAs) are emerging as critical regulators in the pathological process of cerebral ischemia/reperfusion injury. miRNAs play an important role in regulating neuronal survival. miR-135b-5p has been reported as an important miRNA in regulating cell apoptosis. However, the role of miR-135b-5p in regulating neuronal survival remains poorly understood. Here, we aimed to investigate the role of miR-135b-5p in cerebral ischemia/ reperfusion using an in vitro model of oxygen-glucose deprivation and reoxygenation-(OGD/R) induced neuron injury.

MATERIAL AND METHODS

miRNA, mRNA and protein expression was detected by real-time quantitative polymerase chain reaction and Western blot. Cell viability was detected by cell counting kit-8 and lactate dehydrogenase assays. Cell apoptosis was detected by caspase-3 activity assay. Oxidative stress was determined using commercial kits. The target of miR-135b-5p was confirmed by dual-luciferase reporter assay.

RESULTS

We found that miR-135b-5p expression was significantly decreased in hippocampal neurons receiving OGD/R treatment. Overexpression of miR-135b-5p markedly alleviated OGD/R-induced cell injury and oxidative stress, whereas suppression of miR-135b-5p showed the opposite effects. We observed that miR-135b-5p directly targeted the 3'-untranslated region of glycogen synthase kinase-3β (GSK-3β). We found that miR-135b-5p negatively regulates the expression of GSK-3β in hippocampal neurons. Moreover, miR-135b-5p overexpression promotes activation of nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling. However, the restoration of GSK-3β expression significantly reversed the protective effects of miR-135b-5p overexpression.

CONCLUSIONS

Overall, our results suggest that miR-135b-5p protects neurons against OGD/R-induced injury through downregulation of GSK-3β and promotion of the Nrf2/ARE signaling pathway-mediated antioxidant responses.

Protective effect and mechanism of Lactobacillus on cerebral ischemia reperfusion injury in rats

The present study was designed to investigate the protective effects and mechanism of inactivated lactobacillus (ILA) on cerebral ischemia reperfusion injury (CIRI) in rats. In this experiment, 30 male Sprague Dawley rats were randomly divided into control group, IRI groups, and ILA group. A middle cerebral artery occlusion and reperfusion model was prepared. The rats were killed after 24 hours of recovery of blood flow of cerebral ischemia resulting from 60-min occlusion. The cerebral infarction volume and neurological scores were assayed by staining and behavioral observation. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were assayed by biochemical kits. Cell apoptosis was assayed by Tunnel and the Toll-like receptor (TLR)-4, IkB, and A20 were assayed by western blot. The neurobehavioral scores in IRI rats were significantly lower compared to the control group while ILA improved the neurobehavioral scores of the ILA groups. The cerebral infarction volume and neural cell apoptosis of rats in the ILA groups decreased significantly compared with those in the IRI group. In addition, MDA level in the ILA groups decreased whereas SOD activity increased compared to the IRI group. Moreover, ILA also inhibited the expression of TLR-4 and promoted the expression of IkB and A20. ILA inhibited the apoptosis of neural cells, decreased cerebral infarction volume, and reduced oxidative stress through inhibition of TLR-4/NF-kappa B signaling, improving neurobehavioral scores. Thus from the present study it was concluded that ILA has protective effect on CIRI.

Mechanisms of Action of Vitamin D as Supplemental Therapy for Pneumocystis Pneumonia

The combination of trimethoprim and sulfamethoxazole (TMP-SMX) is the most effective regimen for therapy of Pneumocystis pneumonia (PCP). As many patients with PCP are allergic or do not respond to it, efforts have been devoted to develop alternative therapies for PCP. We have found that the combination of vitamin D₃ (VitD3) (300 IU/kg/day) and primaquine (PMQ) (5 mg/kg/day) was as effective as TMP-SMX for therapy of PCP. In this study, we investigated the mechanisms by which vitamin D enhances the efficacy of PMQ. C57BL/6 mice were immunosuppressed by CD4⁺ cell depletion, infected with Pneumocystismurina for 8 weeks, and then treated for 9 days with the combination of VitD3 and PMQ (VitD3-PMQ) or with TMP-SMX or PMQ to serve as controls. The results showed that vitamin D supplementation increased the number of CD11c⁺ cells, suppressed the production of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], gamma interferon [IFN-γ], and interleukin-6 [IL-6]) and inducible nitric oxide synthase (iNOS), and enhanced the expression of genes related to antioxidation (glutathione reductase and glutamate-cysteine ligase modifier subunit), antimicrobial peptides (cathelicidin), and autophagy (ATG5 and beclin-1). These results suggest that the main action of vitamin D is enhancing the ability of the host to defend against Pneumocystis infection.