Autophagy regulates bone loss via the RANKL/RANK/OPG axis in an experimental rat apical periodontitis model.

AIM: Autophagy is involved in human apical periodontitis (AP). However, it is not clear whether autophagy is protective or destructive in bone loss via the receptor activator of nuclear factor-κB ligand (RANKL)/RANK/osteoprotegerin (OPG) axis. This study aimed to investigate the involvement of autophagy via the RANKL/RANK/OPG axis during the development of AP in an experimental rat model. METHODOLOGY: Twenty-four female Sprague-Dawley rats were divided into control, experimental AP (EAP) + saline, and EAP + 3-methyladenine (An autophagy inhibitor, 3-MA) groups. The control group did not receive any treatment. The EAP + saline group and the EAP + 3-MA group received intraperitoneal injections of saline and 3-MA, respectively, starting 1 week after the pulp was exposed. Specimens were collected for microcomputed tomography (micro-CT) scanning, histological processing, and immunostaining to examine the expression of light chain 3 beta (LC3B), RANK, RANKL, and OPG. Data were analysed using one-way analysis of variance (p < .05). RESULTS: Micro-CT showed greater bone loss in the EAP + 3-MA group than in the EAP + saline group, indicated by an elevated trabecular space (Tb.Sp) (p < .05). Inflammatory cell infiltration was observed in the EAP + saline and EAP + 3-MA groups. Compared with EAP + saline group, the EAP + 3-MA group showed weaker expression of LC3B (p < .01) and OPG (p < .05), more intense expression of RANK (p < .01) and RANKL (p < .01), and a higher RANKL/OPG ratio (p < .05). CONCLUSION: Autophagy may exert a protective effect against AP by regulating the RANKL/RANK/OPG axis, thereby inhibiting excessive bone loss.

High-Mobility Group Box 1 in Spinal Cord Injury and Its Potential Role in Brain Functional Remodeling After Spinal Cord Injury.

High-mobility group box 1 (HMGB1) is a nonhistone nuclear protein, the functions of which depend on its subcellular location. It is actively or passively secreted into the blood and/or cerebrospinal fluid (CSF) and can be used as a prognostic indicator of disease. HMGB1 released into the bloodstream can cause pathological reactions in distant organs, and entry into the CSF can destroy the blood-brain barrier and aggravate brain injuries. HMGB1 expression has been reported to be increased in the tissues of spinal cord injury (SCI) patients and involved in the regulation of neuroinflammation, neuronal apoptosis, and ferroptosis. SCI can lead to brain changes, resulting in neuropathic pain, depression, and cognitive dysfunction, but the specific mechanism is unknown. It remains unclear whether HMGB1 plays an important role in brain functional remodeling after SCI. Damaged cells at the site of SCI passively release HMGB1, which travels to the brain via the blood, CSF, and/or axonal transport, destroys the blood-brain barrier, and causes pathological changes in the brain. This may explain the remodeling of brain function that occurs after SCI. In this minireview, we introduce the structure and function of HMGB1 and its mechanism of action in SCI. Clarifying the functions of HMGB1 may provide insight into the links between SCI and various brain regions.

Canonical and noncanonical pyroptosis are both activated in periodontal inflammation and bone resorption.

BACKGROUND AND OBJECTIVE: Pyroptosis has both a caspase-1-dependent canonical pathway and a caspase-4/-5/-11-dependent noncanonical pathway. They play an important role in inflammatory damage and related diseases. Canonical pyroptosis was reported to be involved in periodontitis. However, knowledge of caspase-4/-5/-11-dependent noncanonical pathway involvement remains limited. The aim of this study was to investigate the outcomes of pyroptosis inhibition on periodontitis as well as the possible mechanism, in order to provide a potential target for alleviating periodontitis. METHODS: Human and rat periodontitis tissues were collected for immunohistochemistry (IHC). Micro-computed tomography was used to assess alveolar bone loss in experimental periodontitis model. Pyroptosis-related proteins were tested by western blot. propidium iodide staining and lactate dehydrogenase release were used to verify pyroptosis activation. RNA sequencing was applied to investigate the preliminary mechanism of the reduced periodontal inflammation induced by YVAD-CHO. RESULTS: Both canonical- and noncanonical-related proteins were detected in human and rat periodontitis tissue. The pyroptosis-inhibited group demonstrated less inflammatory response and bone absorption. In vitro, pyroptosis was activated by lipopolysaccharide and inhibited by YVAD-CHO. RNA sequencing demonstrated that the expression of A20 and IκB-ζ was increased and verified by western blot in vitro and IHC in vivo. CONCLUSION: These results suggest that inhibition of pyroptosis-reduced inflammation and alveolar bone resorption in periodontitis.

The correlation of altitude with gingival status among adolescents in western China: a cross-sectional study.

Periodontal disease is common in Chinese adolescents. There is little information about the effect of different altitudes on gingival health. This study aimed to investigate the gingival status at different altitudes and to identify relative factors that affect adolescents' gingival status. A total of 1033 adolescents aged 12-14 years were included in this cross-sectional study in Ganzi (plateau, 1400 m, 2560 m, 3300 m) and Suining (plain, 300 m). Gingival status was assessed by the presence of gingival bleeding on probing (BOP) and dental calculus (DC). Demographic variables, socioeconomic status, dairy habits and oral health-related knowledge, attitudes and behaviors were obtained via questionnaire. Univariate and multivariate binary logistic regression analyses were performed to identify potential relative factors. A total of 64.09% and 77.15% of adolescents had BOP and DC, respectively. The prevalence rates of BOP and DC were higher in the plateau than the plain (P < 0.05). After adjusting for all other factors and interaction terms, residence altitudes of 2560 m [300 m as reference: P < 0.001, odds ratio (OR) = 4.072] and 3300 m (300 m as reference: P = 0.002, OR = 4.053) were significant relative factors of BOP, and an altitude of 2560 m (300 m as reference: P = 0.001, OR = 3.866, 1400 m as reference: P = 0.001, OR = 3.944) was an important relative factor of DC. Gingival bleeding and calculus deposits were common at different altitudes. High altitude was a significant relative factor of gingival bleeding and calculus deposits.

The effects of oral health education regarding periodontal health on non-dental undergraduates in southwestern China-exploring the feasibility of an e-learning course for oral health promotion.

BACKGROUND: The high prevalence of periodontal diseases is an important oral health problem worldwide. It is necessary to increase public knowledge on and influence attitudes towards periodontal diseases in order to prevent them. However, the effect of oral health education (OHE) as a primary preventive method in China is unsatisfactory. The aim of this study is to investigate the feasibility of extending an e-learning course regarding periodontal health by comparing the effects of oral health education regarding periodontal health (OHE-PH) on dental and non-dental students and the effects between a traditional course and an e-learning course among non-dental students at Sichuan University. METHODS: A quasi-experimental study with a pre-test and a post-test was performed. A total of 217 dental students and 134 non-dental students attended a traditional course; 69 non-dental students attended an e-learning course. Before- and after-course questionnaires about periodontal health knowledge, attitudes and behaviours were administered. RESULTS: After the traditional/e-learning course, the knowledge of both dental and non-dental students about periodontal diseases and self-reported behaviours for gingival bleeding and oral care improved. The non-dental students reached or surpassed the level of dental students before the course. The non-dental students taking the e-learning course performed better in some areas than those taking the traditional course. CONCLUSIONS: OHE-PH was effective for dental and non-dental students. The e-learning course on OHE-PH was sufficient for improving knowledge and self-reported behaviours among non-dental undergraduates and was even better than the traditional course in some areas. The e-learning course may be an effective method for periodontal health education and oral health promotion among undergraduates.

Comparison of oral health behaviour between dental and non-dental undergraduates in a university in southwestern China--exploring the future priority for oral health education.

BACKGROUND: Based on a national survey in 2015, people's oral health behaviour (OHB) has not kept up with the pace of knowledge and attitudes in China after decades of oral health education (OHE). Thus, we need to improve OHE to strengthen people's OHB. Undergraduates are regarded as the best candidates for the improvement of OHE. The objective of this study is to determine undergraduates' oral health status and existing problems in OHB by comparing dental and non-dental students at Sichuan University. We hope to provide some suggestions for future OHE to improve people's OHB. METHODS: A quasi-experimental study designed with a pre-test and post-test group was conducted. A total of 217 dental students and 135 non-dental students were enrolled. They were administered an OHE course focused on OHB. A survey about oral health behaviour and knowledge was conducted before and after the course. RESULTS: According to the pre-course survey, dental students surpassed non-dental students in terms of toothbrushing frequency, method, and time, but unfortunately, flossing was overlooked by all the students. After the course, both dental and non-dental students showed strong willingness to improve their OHB. More non-dental students than dental students were willing to use toothpicks and Chinese herbal toothpaste before and after the course. CONCLUSIONS: OHE focused on behaviour has a positive effect on university students. Future OHE and interventions should focus on flossing, toothbrushing methods, toothpicks, Chinese herbal toothpaste and modifications to adopt new media.

miR-494-3p Regulates Cellular Proliferation, Invasion, Migration, and Apoptosis by PTEN/AKT Signaling in Human Glioblastoma Cells.

Malignant gliomas are the most common primary brain tumors, and the molecular mechanisms involving their progression and recurrence are still largely unclear. Substantial data indicate that the oncogene miR-494-3p is significantly elevated in gliomas, but the molecular functions of miR-494-3p in gliomagenesis are largely unknown. The present study aimed to explore the role of miR-494-3p and its molecular mechanism in human brain gliomas, malignant glioma cell lines, and cancer stem-like cells. The expression level of miR-494-3p in 48 human glioma issues and 8 normal brain tissues was determined using stem-loop real-time polymerase chain reaction (PCR). To study the function of miR-494-3p inhibitor in glioma cells, the miR-494-3p inhibitor lentivirus was used to transfect glioma cells. Transwell invasion system was used to estimate the effects of miR-494-3p inhibitor on the invasiveness of glioma cells. A mouse model was used to test the effect of miR-494-3p inhibitor on glioma proliferation and invasion in vivo. Results showed that the expression of miR-494-3p in human brain glioma tissues was higher than in normal brain tissues. Downregulated expression of miR-494-3p can inhibit the invasion and proliferation and promote apoptosis in glioma cells. Quantitative reverse transcription PCR and Western blotting analysis revealed that the expression of PTEN was increased after downexpression of miR-494-3p in glioma cells (U87 and U251). miR-494-3p inhibitor could prevent migration, invasion, proliferation, and promote apotosis in gliomas through PTEN/AKT pathway. Therefore, the study results have shown that miR-494-3p may act as a therapeutic target in gliomas.

Ruminal microbial metagenomes and host transcriptomes shed light on individual variability in the growth rate of lambs before weaning: the regulated mechanism and potential long-term effect on the host.

Weaning weight is a reflection of management during the breastfeeding phase and will influence animal performance in subsequent phases, considered important indicators within production systems. The aims of this study were as follows: (i) to investigate variability in the growth rate among individual lambs from ewes rearing single or twin lambs fed with two different diets and (ii) to explore the molecular mechanisms regulating the growth rate and the potential long-term effects on the host. No significant change in lamb average daily gain (ADG) was observed in litter size and diet treatment, and there were large variations among individual lambs (ranging from 0.13 to 0.41 kg/day). Further analysis was conducted on serum amino acids, rumen fermentation characteristics, rumen metagenomics and transcriptome, and hepatic transcriptome of lambs with extremely high (HA; n = 6) and low (LA; n = 6) ADG. We observed significant increases in serum lysine, leucine, alanine, and phenylalanine in the HA group. The metagenome revealed that the HA group presented a higher rumen propionate molar proportion via increasing gene abundance in the succinate pathway for propionate synthesis. For the rumen transcriptome, higher expressed gene sets in the HA group were mainly related to rumen epithelial growth, including cytokine-cytokine receptor interaction, Jak-STAT signaling pathway, and adherens junction. For the liver transcriptome, the upregulated KEGG pathways in the HA group were primarily associated with fatty acid degradation, glyoxylate and dicarboxylate metabolism, cholesterol metabolism, and the immune system. This research suggests that preweaning lambs with high ADG may benefit from rumen development and enhanced liver metabolic and immune function. IMPORTANCE: There is accumulating evidence indicating that the early-life rumen microbiome plays vital roles in rumen development and microbial fermentation, which subsequently affects the growth of young ruminants. The liver is also vital to regulate the metabolism and distribution of nutrients. Our results demonstrate that lambs with high average daily gain (ADG) enhanced microbial volatile fatty acid (VFA) metabolism toward rumen propionate and serum amino acid (AA) production to support host growth. The study highlights that high ADG in the preweaning period is beneficial for the rumen development and liver energy metabolism, leading to better growth later in life. Overall, this study explores the molecular mechanisms regulating the growth rate and the potential long-term effects of increased growth rate on the host metabolism, providing fundamental knowledge about nutrient manipulation in pre-weaning.

Brain region changes following a spinal cord injury.

Brain-related complications are common in clinical practice after spinal cord injury (SCI); however, the molecular mechanisms of these complications are still unclear. Here, we reviewed the changes in the brain regions caused by SCI from three perspectives: imaging, molecular analysis, and electrophysiology. Imaging studies revealed abnormal functional connectivity, gray matter volume atrophy, and metabolic abnormalities in brain regions after SCI, leading to changes in the structure and function of brain regions. At the molecular level, chemokines, inflammatory factors, and damage-associated molecular patterns produced in the injured area were retrogradely transmitted through the corticospinal tract, cerebrospinal fluid, or blood circulation to the specific brain area to cause pathologic changes. Electrophysiologic recordings also suggested abnormal changes in brain electrical activity after SCI. Transcranial magnetic stimulation, transcranial direct current stimulation, and deep brain stimulation alleviated pain and improved motor function in patients with SCI; therefore, transcranial therapy may be a new strategy for the treatment of patients with SCI.

Potential significance of high-mobility group protein box 1 in cerebrospinal fluid.

High-mobility group protein box 1 (HMGB1) is a cytokine with multiple functions (according to its subcellular location) that serves a marker of inflammation. CSF HMGB1 could be the part of pathological mechanisms that underlie the complications associated with CNS diseases. HMGB1 actively or passively released into the CSF is detected in the CSF in many diseases of the central nervous system (CNS) and thus may be useful as a biomarker. Pathological alterations in distant areas were observed due to lesions in a specific region, and the level of HMGB1 in the CSF was found to be elevated. Reducing the HMGB1 level via intraventricular injection of anti-HMGB1 neutralizing antibodies can improve the outcomes of CNS diseases. The results indicated that CSF HMGB1 could serve as a biomarker for predicting disease progression and may also act as a pathogenic factor contributing to pathological alterations in distant areas following focal lesions in the CNS. In this mini-review, the characteristics of HMGB1 and progress in research on CSF HMGB1 as a biomarker of CNS diseases were discussed. CSF HMGB1 is useful not only as a biomarker of CNS diseases but may also be involved in interactions between different brain regions and the spinal cord.

Blood Metabolites and Faecal Microbial Communities in Nonpregnant and Early Gestation Ewes in Highly Cold Areas.

Ewes undergo complex metabolic changes during pregnancy. Understanding the specific process of these changes is a necessary prerequisite in ewes for regulating and intervening in order to maintain pregnancies. However, there have been relatively few studies on the specific changes that occur in nutritional metabolism in pregnant ewes during early gestation, especially for some landrace ewes in highly cold areas. Therefore, this study aimed to (1) elucidate the changes in metabolites and microbial communities in pregnant ewes during early gestation using metabolomics and 16S ribosomal RNA gene (rDNA) amplicon sequencing approaches, and to (2) discover novel early pregnancy-induced biomarkers in the blood and faeces. Rams were placed together with ewes on D0 and removed on D45. During early gestation, blood and faecal samples were collected from ewes in a highly cold area for analysing the metabolites and microbial communities; these were retrospectively classified as the early gestation pregnant (EP) ewe group or the nonpregnant (NP) ewe group based on the lambing status recorded during the expected delivery period. The differences in the plasma biochemical parameters, plasma metabolites, and faecal microbial communities of pregnant and nonpregnant ewes were characterised. The GC, IL-6, O-acetyl-l-serine, L-glutamine, and 6-acetamido-2-oxohexanoic acid were screened out as potential biomarkers for evaluating the occurrence of early pregnancy. These novel early pregnancy-induced metabolites discovered in ewes might allow for the development of technologies to detect early pregnancies in sheep in highly cold areas.

Metformin Attenuates Ferroptosis and Promotes Functional Recovery of Spinal Cord Injury.

BACKGROUND: Ferroptosis is involved in traumatic spinal cord injury (SCI), and its inhibition may improve functional recovery after traumatic SCI. This study investigated whether metformin (Met) can have a neuroprotective effect in SCI repair by inhibiting ferroptosis. METHODS: We assessed functional change to determine the long-term effects after intraperitoneal injection of Met in SCI rats with the Basso-Beattie-Bresnahan locomotor rating scale. Malondialdehyde level and relative expression of key proteins, inflammatory cytokines, and nuclear factor E2-related factor 2 signalling molecules were determined in SCI rats and PC12 cells exposed to FeCl3 solution. RESULTS: Met treatment decreased the contents of malondialdehyde, regulated the levels of inflammatory factors, activated the nuclear factor E2-related factor 2 signalling pathway, and improved long-term outcomes by ameliorating SCI-induced locomotor deficits. In vitro studies further confirmed the beneficial and antiferroptotic actions of Met partly through activation of nuclear factor E2-related factor 2 signalling. CONCLUSION: Met can have a neuroprotective effect on SCI repair partly through antiferroptotic effects.

MiR-181a-5p Alleviates the Inflammatory Response of PC12 Cells by Inhibiting High-Mobility Group Box-1 Protein Expression.

OBJECTIVE: Neuroinflammation triggers sequelae after spinal cord injury (SCI). Inhibition of inflammation promotes recovery after SCI. MicroRNAs regulate many pathophysiological processes, including inflammation. Any role for miR-181a-5p in the inflammatory response after SCI remains unclear. Thus, we evaluated the effects of miR-181a-5p on inflammation in PC12 cells and the underlying mechanism in play. METHODS: Quantitative reverse transcription-polymerase chain reaction was used to measure the levels of miR-181a-5p and high-mobility group box-1 protein (HMGB1) in SCI tissues. Cell-counting kit-8 assays were used to assess the viability of PC12 cells treated with lipopolysaccharide (LPS). Plasmids encoding MiR-181a-5p mimics, an miR-181a-5p inhibitor, or/and the HMGB1 were transfected into PC12 cells. Quantitative reverse transcription-polymerase chain reaction or/and Western blotting were performed to assess the expression of miR-181a-5p, HMGB1, and inflammatory factors in vitro. RESULTS: MiR-181a-5p expression decreased and HMGB1 expression increased in SCI tissues and LPS-induced PC12 cells. Upregulation of miR-181a-5p (via transfection) inhibited inflammation of, and HMGB1 expression by, LPS-induced PC12 cells. HMGB1 overexpression reversed the anti-inflammatory effects of miR-181a-5p. Dual-luciferase assays confirmed that HMGB1 was a direct target of miR-181a-5p. CONCLUSIONS: miR-181a-5p attenuated the inflammatory response of LPS-induced PC12 cells by directly inhibiting HMGB1; thus, miR-181a-5p may serve as a therapeutic target in SCI.

Double-Edged Sword Effect of Pyroptosis: The Role of Caspase-1/-4/-5/-11 in Different Levels of Apical Periodontitis.

The study was to investigate the effect of canonical and noncanonical pyroptosis in apical periodontitis. Proteins' profiles of human apical periodontitis tissue were analyzed by label-free proteomics. Immunofluorescence was used to detect proteins related to pyroptosis in human apical periodontitis tissues and experimental apical periodontitis models. A dual experimental apical periodontitis model with both smaller (mandible) and larger (maxilla) bone lesions was established. THP-1-derived macrophages were stimulated with P. gingivalis lipopolysaccharide in vitro with or without the caspase-1/-4/-5 inhibitor Ac-FTDL-CMK. Propidium iodide staining, lactic dehydrogenase release and Western blot were applied to evaluate cell death and the protein expression. Caspase-1/-4/-5 were expressed in human apical periodontitis tissues. Caspase-1/-11 were involved in bone loss in experimental apical periodontitis. Caspase-1/-11 inhibitors reduced bone loss in larger lesions (maxilla) but accelerated bone loss in smaller lesions (mandible). Caspase-1/-4/-5 inhibitors also showed double-edged sword effects on propidium iodide staining and lactic dehydrogenase release in vitro. The expression of cleaved-caspase-1/-4/-5, mature interluekin-1ß and gasdermin D N-terminal domain increased in THP-1-derived macrophages after lipopolysaccharide stimulation but decreased after treatment with Ac-FTDL-CMK. Pyroptosis contributed to apical periodontitis and excited a double-edged sword effect in inducing bone loss in vivo and cell death in vitro.

Bioinformatics analysis constructs potential ferroptosis-related ceRNA network involved in the formation of intracranial aneurysm.

Background: Intracranial aneurysm (IA) causes more than 80% of nontraumatic subarachnoid hemorrhages (SAHs). The mechanism of ferroptosis involved in IA formation remains unclear. The roles played by competitive endogenous RNA (ceRNA) regulation networks in many diseases are becoming clearer. The goal of this study was to understand more fully the ferroptosis-related ceRNA regulation network in IA. Materials and methods: To identify differentially expressed genes (DEGs), differentially expressed miRNAs (DEMs), and differentially expressed lncRNAs (DELs) across IA and control samples, the GEO datasets GSE122897 and GSE66239 were downloaded and analyzed with the aid of R. Ferroptosis DEGs were discovered by exploring the DEGs of ferroptosis-related genes of the ferroptosis database. Potentially interacting miRNAs and lncRNAs were predicted using miRWalk and StarBase. Enrichment analysis was also performed. We utilized the STRING database and Cytoscape software to identify protein-protein interactions and networks. DAB-enhanced Prussian blue staining was used to detect iron in IA tissues. Results: Iron deposition was evident in IA tissue. In all, 30 ferroptosis DEGs, 5 key DEMs, and 17 key DELs were screened out for constructing a triple regulatory network. According to expression regulation of DELs, DEMs, and DEGs, a hub triple regulatory network was built. As the functions of lncRNAs are determined by their cellular location, PVT1-hsa-miR-4644-SLC39A14 ceRNA and DUXAP8-hsa-miR-378e/378f-SLC2A3 ceRNA networks were constructed. Conclusion: CeRNA (PVT1-hsa-miR-4644-SLC39A14 and DUXAP8-hsa-miR-378e/378f-SLC2A3) overexpression networks associated with ferroptosis in IA were established.

Potential Role of the Chemotaxis System in Formation and Progression of Intracranial Aneurysms Through Weighted Gene Co-Expression Network Analysis.

BACKGROUND: Intracranial aneurysm (IA) is the most common and is the main cause of spontaneous subarachnoid hemorrhage (SAH). The underlying molecular mechanisms for preventing IA progression have not been fully identified. Our research aimed to identify the key genes and critical pathways of IA through gene co-expression networks. METHODS: Gene Expression Omnibus (GEO) datasets GSE13353, GSE54083 and GSE75436 were used in the study. The genetic data were analyzed by weighted gene co-expression network analysis (WGCNA). Then the clinically significant modules were identified and the differentially expressed genes (DEGs) with the genes were intersected in these modules. GO (gene ontology) and KEGG (Kyoto Gene and Genomic Encyclopedia) were used for gene enrichment analysis to determine the function or pathway. In addition, the composition of immune cells was analyzed by CIBERSORT algorithm. Finally, the hub genes and key genes were identified by GSE122897. RESULTS: A total of 266 DEGs and two modules with clinical significance were identified. The inflammatory response and immune response were identified by GO and KEGG. CCR5, CCL4, CCL20, and FPR3 were the key genes in the module correlated with IA. The proportions of infiltrating immune cells in IA and normal tissues were different, especially in terms of macrophages and mast cells. CONCLUSION: The chemotactic system has been identified as a key pathway of IA, and interacting macrophages may regulate this pathological process.

[Retracted] miR­218­5p inhibits the stem cell properties and invasive ability of the A2B5+CD133­ subgroup of human glioma stem cells.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that Fig. 5 on p. 874 contained a series of DAPI panels within the figure that looked unexpectedly similar in appearance, with the similarities also evident in the second and 'Merge' data columns; moreover, of especial note, the similarities in the 'DAPI' panels for the Blank control experiments shown in Fig. 5C and D only affected a partial section of the data. In addition, the 'blank' and 'miR­control' panels in Fig. 6A also appeared to contain overlapping data. Independently of the issues that were raised by the interested reader, the authors themselves requested that their paper be retracted on account of having identified some problems with the presentation of various of the figures, and no longer being able to access their original data. The Editor of Oncology Reports has agreed that this paper should be retracted from the Journal, and apologizes to the readership for any inconvenience caused. [Oncology Reports 35: 869­877, 2016; DOI: 10.3892/or.2015.4418].

Glycyrrhizic Acid Attenuates the Inflammatory Response After Spinal Cord Injury by Inhibiting High Mobility Group Box-1 Protein Through the p38/Jun N-Terminal Kinase Signaling Pathway.

BACKGROUND: Neuroinflammation is an important secondary aggravating factor in spinal cord injury (SCI). Inhibition of the inflammatory response is critical for SCI treatment. Glycyrrhizic acid (GA) is an anti-inflammatory drug, but its utility for SCI is unclear. This study aimed to evaluate the effects of GA on inflammation after SCI and the underlying mechanism. METHODS: Cell counting kit-8 assays were performed to assess the viability of highly aggressively proliferating immortalized cells that had been treated with lipopolysaccharide (LPS) and/or GA. Reverse transcription quantitative polymerase chain reaction and Western blotting were performed to assess expression of high mobility group box-1 protein (HMGB1), ionized calcium binding adaptor molecule 1, and inflammatory factors in vitro and in vivo. GA (100 mg/kg) was intraperitoneally injected into rats. Anti-inflammatory effects of GA were analyzed in SCI tissues. p38/Jun N-terminal kinase signaling pathway proteins were analyzed by Western blotting. RESULTS: Cell counting kit-8 assay results showed that treatment with 100 ng/mL LPS for 12 hours was optimal. After LPS treatment, highly aggressively proliferating immortalized cells were activated; messenger RNA expression levels of HMGB1 and inflammatory factors were increased. GA significantly inhibited LPS-induced HMGB1 expression and inflammatory responses, as determined by reverse transcription quantitative polymerase chain reaction and Western blotting. Transfection with an HMGB1-overexpression plasmid reversed the anti-inflammatory effects of GA. In addition, intraperitoneal injection of GA (100 mg/kg) into rats for 3 days significantly reduced expression levels of HMGB1 and inflammatory factors after SCI in vivo. GA reduced phosphorylation, but not levels, of p38 and Jun N-terminal kinase proteins. CONCLUSIONS: GA attenuates the inflammatory response after SCI by inhibiting HMGB1 through the p38/JNK signaling pathway and thus has therapeutic potential for SCI.

[Binding mechanism of rhaponticin and human serum albumin].

The interaction mechanism between rhaponticin (RT) and human serum albumin (HSA) has been studied by fluorescence spectroscopy and absorbance spectra. The mediation effect that the metal ions took part in the interaction has also been discussed in this paper. Based on different theoretical models of fluorescence quenching, the binding constant (K) and binding sites (n) of the interaction were determined and analyzed comparatively. The quenching mechanism of the binding reaction has also been discussed. The binding distance (r) and energy-transfer efficiency (E) between RT/RT-Co(II)/RT-Ni(II) and HSA were also obtained by virtue of the Förster theory of non-radiation energy transfer. The effect of RT acting on the HSA's conformation was analyzed by synchronous fluorescence spectroscopy. The result showed that the result calculated by different theoretical models is generally equivalent and RT bound HSA strongly by forming stable complex, which indicates that HSA under physiological conditions can act as a carrier for RT to be transported to exert effects. The microconformation of HSA changed significantly due to hydrophobicity change in the chemical environment of some fluorescence chromophores in the subdomain IIA and IIB of HSA. Metal ions Co(II) and Ni(II) can mediate RT-HSA interaction, making the binding of the drug to protein stronger, which indicates that Co(II) and Ni(II) can enhance rhaponticin's medical efficacy under physiological conditions.

Potential Correlation Between Depression-like Behavior and the Mitogen-Activated Protein Kinase Pathway in the Rat Hippocampus Following Spinal Cord Injury.

BACKGROUND: Depression induced by spinal cord injury (SCI) has been demonstrated in clinical and experimental studies; it significantly impacts patients' lives and may be associated with changes in the hippocampus. However, the biological mechanisms underlying depression after SCI are unknown. The mitogen-activated protein kinase (MAPK) signaling pathway participates in potential mechanisms of depression; it is unknown whether this pathway plays a role in SCI-induced depression. METHODS: We applied an animal model of depression induced by SCI, established using an aneurysm clip, to determine whether MAPK activation in the hippocampus is associated with depression-like behavior. RESULTS: SCI led to depression-like behavior, such as anhedonia in the sucrose preference test, decreased number of crossings in the open field test, decreased body weight, and decreased immobility time in the forced swim test. Western blot analysis further showed that SCI significantly increased the levels of phosphorylated p38 MAPK and cleaved caspase-3 in the hippocampus and inhibited the phosphorylation of extracellular signal-related kinase 1/2 and c-Jun N-terminal kinase 1/2. In addition, there were significant negative correlations between depression-like behavior and phosphorylated extracellular signal-related kinase 1/2 and positive correlations between depression-like behavior and phosphorylated p38 MAPK and cleaved caspase-3. CONCLUSIONS: These findings suggest that the MAPK pathway in the rat hippocampus may be involved in the pathophysiology of depression induced by SCI.