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The present study aimed to investigate whether brain death (BD) induces the activation of endoplasmic reticulum stress (ERS) and protein phosphatase 2A (PP2A), and reveal the possible association with BD‑induced liver cell apoptosis. A total of 30 healthy adult male Sprague‑Dawley rats were randomized into three groups: Sham‑operated group (S), BD group and 4‑phenylbutyric acid group (BD + 4‑PBA), with 10 rats in each group. All rats were anesthetized. The model of BD was established by inflating a balloon catheter that was placed into the extradural space after anesthesia. 4‑PBA was administered via an intraperitoneal injection when the BD model was established. Anesthesia of the S group of rats was maintained for 6 h. Liver tissues were harvested after 6 h of BD. HE staining was used to evaluate the damage of liver. Terminal deoxynucleotidyl transferase‑mediated 2'‑deoxyuridine 5'‑triphosphate nick‑end labeling staining was used to observe the apoptosis of liver cells. Activation of ERS and PP2A was examined by western blotting and immunohistochemical staining. We reported that the apoptosis of liver cells after BD was significantly promoted than in the S group. Activation of ERS and PP2A was induced in the BD group when compared with S group. Phosphorylation of PP2A was suppressed in BD group. Application of 4‑PBA decreased the activation of ERS and apoptosis rate compared with the BD group. In addition, activation of PP2A in the BD + 4‑PBA group was decreased due to the reduction of PP2A phosphorylation compared with the BD group, but the levels were higher than in the S group. (P

Hypothermic machine perfusion (HMP) effectively reduces ischemia‑reperfusion injury (IRI) in livers donated after circulatory death (DCD) when compared with cold storage (CS). However, the underlying mechanisms remain unclear. The current study aimed to investigate the cellular mechanisms by which HMP ameliorates the inflammatory response during IRI. Adult male Sprague‑Dawley rat livers were exposed to 30 min of warm ischemia following cardiac arrest and preserved by CS or HMP for 3 h (n=3 per group). The severity of IRI was assessed in vitro on normothermic reperfusion for 2 h, and intrahepatic resistance (IHR) and bile production were subsequently recorded. The perfusate was analyzed for transaminase leakage and oxygen consumption. Livers were subsequently subjected to histological examination, and measurement of adenosine triphosphate (ATP) levels, malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, nicotinamide adenine dinucleotide (NAD)+ levels and the ratio of NAD+/NADH. In addition, the protein expression of sirtuin‑1 (SIRT‑1), acetylated‑nuclear factor‑κB (NF‑κB) p65 and NF‑κB p65 was detected by western blotting, and the mRNA expression of the inflammatory cytokines interleukin (IL)‑6 and tumor necrosis factor (TNF)‑α was determined by reverse transcription‑quantitative polymerase chain reaction. Compared with CS, HMP resulted in significantly lower IHR, transaminase leakage and MDA levels, and higher oxygen consumption, ATP levels and SOD activity. In addition, improved preservation of hepatic histology was observed in HMP compared with CS. The mRNA expression of NF‑κB p65, IL‑6 and TNF‑α was significantly decreased in the HMP group compared with CS samples. Under HMP preservation, SIRT‑1 activity and protein expression were increased, while the protein expression of acetylated‑NF‑κB p65 was decreased, compared with CS. These results indicate that HMP may reduce the inflammatory response during IRI via SIRT‑1‑mediated deacetylation of NF‑κB p65. These findings may provide a theoretical basis for the clinical application of HMP as an effective strategy to preserve DCD livers.

A previous study has demonstrated a progression in the nerve regeneration by polyaniline/cellulose (PANI/RC), although the underlying mechanism was not elucidated. In the present study, regenerated nerves were investigated, using histological techniques, functional assays and western blot analysis. The triceps surae muscle weight ratio percentages of the sham, regenerated cellulose (RC) and the PANI/RC groups were 38.88±4.76 and 76.32±7.11%, respectively. The thickness of the myelin sheath for the aforementioned groups were as follows: 1.2±0.27; 0.49±0.21 and 0.93±0.28 µl. Western blot analysis demonstrated that the ciliary neurotrophic factor (CNTF) and brain‑derived neurotrophic factor (BDNF) were highly expressed in the regenerated nerve in the presence of polyaniline. Phosphorylated extracellular kinase (p‑ERK)1/2 expression in the PANI/RC group was significantly elevated compared with the RC group (1.83‑fold) and the sham group (4.92‑fold). The expression of the axon sprout‑associated proteins, such as Tau, α‑tubulin and growth associated protein‑43, were increased (1.64, 1.59 and 1.24‑fold, respectively) compared with the RC group. The results demonstrated that PANI enhances the expression and secretion of BDNF and CNTF, activates the ERK1/2 signaling pathway and increases the expression levels of the GAP‑43, Tau and α‑tubulin, suggesting an insight into nerve regeneration and possible clinical interventions in nerve injury.

The present study aimed to investigate the function and possible underlying mechanism of various concentrations of visceral adipose tissue‑derived serine protease inhibitor (vaspin) on leptin‑induced inflammatory and metabolic responses in rat chondrocytes. Rat articular chondrocytes were isolated and treated with different concentrations of vaspin, which was followed by stimulation with leptin. The expression of genes, secretion of nitric oxide and tumor necrosis factor‑α, and activation of the nuclear factor (NF)‑κB pathway were analyzed by reverse transcription‑quantitative polymerase chain reaction, ELISA and western blotting. The results demonstrated that vaspin inhibited the leptin‑induced upregulated gene expression levels of leptin receptor (OB‑Rb), a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS)‑4, ADAMTS‑5, matrix metalloproteinase (MMP)‑2 and MMP‑9, and the secretion of NO and TNF‑α, in a dose‑dependent manner. The phosphorylation of inhibitor of NF‑κB (IκB), IκB kinase (IKK)α, IKKβ and NF‑κB were also promoted by leptin in the chondrocytes, which were also suppressed by increased concentration of vaspin. Taken together, results demonstrated that vaspin prevented leptin‑induced inflammation and catabolism by inhibiting the activation of NF‑κB in rat chondrocytes.

Stanniocalcin-1 (STC1) is involved in cancer progression; however, the function of STC1 in glioblastoma remains unknown. In the present study, the expression levels of STC1 protein in glioblastoma were detected using immunohistochemistry. The expression levels of STC1, SMAD2/3 and SMAD4 proteins, following silencing of STC1, were assessed via western blotting. EdU and Transwell assays were performed to determine the proliferation and migration ability of the cells. The mRNA expression levels of STC1, SMAD4 and microRNA (miR)-34a were determined using quantitative PCR. The expression levels of STC1 were increased in glioblastoma tissues. STC1 revealed a significant association with poor outcome in patients with glioblastoma (P

Osteoarthritis (OA) is a chronic joint disease involving cartilage erosion and matrix degradation. Costunolide is a sesquiterpene lactone that has been demonstrated to exert anti‑inflammatory activities in a wide variety of cells. The aim of the present study was to investigate the effect of costunolide in OA treatment, using rat chondrocytes and an OA rat model, in which animals were subjected to destabilization of the medial meniscus. The results revealed that costunolide (2‑6 µM) had no effect on chondrocyte viability or phenotype maintenance. Costunolide decreased the interleukin (IL)‑1β‑induced upregulation of matrix metalloproteinases (MMPs), inducible nitric oxide synthase, cyclooxygenase‑2 and IL‑6, and increased the expression of collagen II and transcription factor SOX‑9, which were inhibited by IL‑1β. Costunolide significantly decreased p65 phosphorylation induced by IL‑1β and the translocation of p65 into the nucleus of rat chondrocytes, as observed by western blot analysis and immunofluorescence staining. In addition, activation of the Wnt/β‑catenin signaling pathway was inhibited by costunolide, as demonstrated by the level of activation of β‑catenin and the transfer of β‑catenin into the nucleus induced by IL‑1β. In vivo, cartilage treated with costunolide exhibited attenuated degeneration and lower Mankin scores compared with the OA group. The present study investigated the anti‑osteoarthritic effects of costunolide, which exerted anti‑inflammatory activities and inhibited MMPs expression. Taken together, these results indicate that costunolide may have a potential value in the treatment of OA.

Oxidative stress induced by ischemia and hypoxia in the livers of donors after brain death (DBD) is associated with poor organ function and low patient survival rates in those receiving DBD liver transplants. Peroxiredoxin 6 (Prdx6) can defend cells against liver damage induced by oxidative stress. The present study aimed to investigate the role of Prdx6 in ischemia- and hypoxia-induced liver damage in DBD livers. Liver tissue samples from ten DBD patients were collected. The control group constituted of six liver samples from patients with liver hemangioma that had accepted tumor excision surgery. Protein expression levels were determined by western blotting, cell viability was assessed using a CCK-8 assay, intracellular reactive oxygen species (ROS) levels were measured using a ROS assay kit, and phospholipase A2 (PLA2) activity was measured using a PLA2 assay kit. In DBD liver samples, Prdx6 expression was downregulated and the nuclear factor-κB (NF-κB) signaling pathway was activated. Furthermore, when human liver L02 cells were exposed to ischemia and hypoxia, the expression of Prdx6 was reduced, causing an increase in reactive oxygen species (ROS); this in turn activated NF-κB signaling and lowered cell viability (P

The present study aimed to investigate the virulence diversity of Helicobacter pylori (H. pylori) in major ethnic groups residing in Guizhou province, China, and its association with clinical outcomes. Gastric mucosal biopsies were collected from the pylorus of patients with gastrointestinal disorders. H. pylori was identified by colonial morphology, Gram staining, a urease test and H. pylori‑specific 16S rRNA gene fragment PCR amplification. DNA was extracted from pure culture and used for virulence gene analysis. The cytotoxin associated gene A (cagA), vacuolating cytotoxin A (vacA) and induced by contact with epithelium gene A (iceA) genes were analyzed by polymerase chain reaction analysis. The cagA gene was further analyzed through sequencing of the C‑terminal region containing EPIYA motifs, and phylogenetic analysis of the cagA C‑terminal variable region was performed using MEGA 6.0 software. In the present study, 73 H. pylori strains were isolated from clinical samples. cagA genotypes were detected in all strains, namely cagA‑AB, ‑ABC, ‑ABD and ‑BD genotypes were found in five (6.85%), three (4.11%), 63 (86.30%) and two (2.74%) isolates, respectively. Phylogenetic analysis showed that there was a clustering association between the cagA‑AB and cagA‑ABC genotypes, and between the cagA‑ABD and cagA‑BD genotypes. In terms of the frequency of the four EPIYA or EPIYA‑like motifs, the most predominant was EPIYA (92.92%), followed by EPIYT (3.77%), ESIYA (2.83%) and ESIYT (0.47%). The predominant vacA genotype was s1c/m2 (65.75%), and the predominant iceA genotype was iceA1 (79.45%). There were no associations between the H. pylori cagA, vacA or iceA genotypes and clinical outcomes. No significant difference was found in the distribution of these genotypes according to the age, ethnicity or location of residence of patients. In conclusion, H. pylori isolated from patients in Guizhou region, China, showed a unique genotype, which was mainly East Asia‑type cagA (ABD), vacA s1c/m2 genotype or iceA1‑postiive. These results provide important information on the distribution of H. pylori virulence genotypes in Guizhou province, China.

Hypothermic machine perfusion (HMP) has been demonstrated to be a more effective method for preserving livers donated after circulatory death (DCD) than cold storage (CS); however, the underlying mechanisms remain unclear. The aim of the present study was to investigate the protective effects of HMP on rat DCD livers and the possible role of the nuclear factor erythroid 2‑related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway. A total of 18 adult male rats were randomly divided into three groups: Control, HMP and CS (n=6 per group). To simulate the conditions of DCD liver transplantation, rat livers in the CS and HMP groups were subjected to 30 min warm ischemia following cardiac arrest and were then preserved by CS or HMP for 3 h. Subsequently, after 1 h of isolated reperfusion, the extent of ischemia/reperfusion injury (IRI) and cellular functions were assessed. During reperfusion, intrahepatic resistance and bile production were measured, and the perfusion fluid was collected for liver enzyme analysis. The liver tissues were then harvested for the assessment of malondialdehyde (MDA) production, superoxide dismutase (SOD) activity, ATP levels, as well as for histological analysis, immunohistochemistry and a terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Finally, the expression levels of the components associated with the Nrf2‑ARE signaling pathway were analyzed via western blotting and reverse transcription‑quantitative polymerase chain reaction. The results of the present study revealed that, compared with in the CS group, the HMP group exhibited higher levels of ATP, bile production and SOD activity, and improved histological results; however, lower levels of liver enzymes, apoptosis and MDA were detected. Additionally, the findings of the present study also suggested that the Nrf2‑ARE signaling pathway may be activated by the steady laminar flow of HMP. In conclusion, HMP may attenuate ischemia‑reperfusion injury to rat DCD livers via activation of the Nrf2‑ARE signaling pathway.

Tight junctions (TJs) are a critical component in maintaining the intestinal mucosal barrier function and gastrointestinal health of animals. Gut barrier dysfunction contributes to the initiation and development of sepsis which induces an uncontrollable systemic inflammatory response and gives rise to life‑threatening clinical conditions. Excretory‑secretary antigens from Trichimella spiralis (T. spiralis) have been reported to protect from sepsis in a mouse model, however the mechanism remains to be elucidated. Mice were treated with recombinant T. spiralis 53‑kDa glycoprotein (rTsP53) at 2 or 6 h following lipopolysaccharide (LPS) injection. Survival rate, serum systemic inflammation, Chiu's score, D‑lactic acid (D‑LA) and diamine oxidase (DAO) as intestinal injured biomarkers, bacterial translocation and growth in peritoneal fluid (PF) and mesenteric lymph nodes (MLN), intestinal tight junction structure and protein zona occludens (ZO)‑1 expression were investigated. In LPS‑induced septic mice, rTsP53 was demonstrated to protract the survival and inhibit serum systemic inflammatory response, and then, allayed morphological alteration, decreased the release of D‑LA and DAO from intestines. Furthermore, LPS‑induced intestinal permeability, bacterial translocation and growth in PF, MLN and vital organs were significantly suppressed by rTsP53 treatment. Notably, rTsP53 treatment markedly improved the intestinal tight junction damaged in sepsis via promoting ZO‑1 expression. These results demonstrated that rTsP53 ameliorated LPS‑induced intestinal injury and is a potential protective agent for treatment of sepsis.

Tendon adhesion is a common problem in the healing of injured tendons. The molecular mechanisms of the TGF-β/Smad signaling pathway have been determined, and the role of TGF-β has been well characterized in wound healing. However, the intracellular mechanism or downstream signals by which TGF-β3 modulates its effects on tendon healing have not been well elucidated. The aim of this study was to determine the effect of TGF‑β3 on the TGF-β/Smad signaling pathway in tenocytes. Quantitative polymerase chain reaction and western blot analysis were used to analyze the effect of TGF‑β3 on the regulation of the expression of Smad proteins in tenocytes. The results demonstrated that TGF‑β3 has no significant effect on the proliferation of tendon cells. The addition of TGF‑β3 to tenocytes can significantly downregulate the expression of Smad3 and upregulate the expression of Smad7 at the gene and protein levels. The results demonstrate that TGF‑β3 may regulate Smad3 and Smad7 proteins through the TGF-β/Smad signaling pathway to minimize extrinsic scarring. Thus, it may provide a novel approach to decrease tendon adhesion and promote tendon healing.