S1PR2 deficiency enhances neuropathic pain induced by partial sciatic nerve ligation

Background/aim: Sphingosine 1-phosphate receptor 2 (S1PR2), a member of the seven-transmembrane receptor family, can be activated by its natural ligand sphingosine 1-phosphate (S1P) to initiate signal transduction and is involved in a wide range of biological effects such as immune cell migration and vascular permeability. Its relationship with neuropathic pain (NP) has not been reported. In this study, the effects of S1PR2 on the development of NP were studied. Materials and methods: We generated a model of NP by partial sciatic nerve ligation (pSNL). The 50% paw withdrawal threshold of the wild-type (WT) group and the S1PR2 deficiency group were measured at several time points after surgery. The inflammatory factor levels of the two groups were measured by real-time quantitative polymerase chain reaction (RT-PCR). Neutrophil infiltration and glial cell activation were detected by immunofluorescence. Matrix metalloproteinase 9 (MMP9) and its substrate myelin basic protein (MBP) were measured by RT-PCR, western blotting, and immunofluorescence. Result: The S1PR2 deficiency group showed a reduction in 50% paw withdrawal threshold compared with WT mice (P < 0.05) at 3 days after the operation. In the ligated sciatic nerve of the S1PR2 deficiency group, the mRNA expression of IL-1ß was increased; the numbers of infiltrating neutrophils and activated astrocytes were also increased. The expression of MMP9 was elevated while MBP was decreased. Conclusion: S1PR2 deficiency could increase the pain sensitivity of a NP mouse model and promote the development of NP

[Inhibitory effect of suramin on inflammatory response in pulmonary tissue and peripheral blood in LPS-induced septic mice].

OBJECTIVE: To investigate the effect of suramin on inflammatory response in pulmonary tissue and peripheral blood in septic mice. METHODS: Twenty-four male C57BL/6 mice were randomly divided into two groups, and suramin(5 mg/kg) or normal saline was intravenously injected 30 min before LPS(5 mg/kg)infusion, respectively. The contents of TNF-α and IL-6 in pulmonary tissue and peripheral blood were detected by ELISA. Suramin or saline-pretreated human mononuclear THP-1 cells were treated with 100 ng/mL LPS in vitro. The expression of TNF-α and IL-6 mRNA and the activity of NF-κB were analyzed by quantitative PCR and Western blotting at different time points after LPS treatment, respectively. RESULTS: Compared with the saline group, the TNF-α and IL-6 levels in pulmonary tissue and peripheral blood were significantly reduced in suramin group at 24 h after LPS treatment(all P<0.01); while there was no significant difference at 72 h between two groups(all P>0.05). The expression of TNF-α, IL-6 mRNA and the activity of NF-κB was decreased in suramin group at different time points after LPS treatment. CONCLUSION: Suramin can protect LPS-induced acute lung injury through down-regulation of systemic and pulmonary pro-inflammatory factors, which may be associated with the inhibition of NF-κB activity.

Mindfulness Meditation for Primary Headache Pain: A Meta-Analysis.

BACKGROUND: Several studies have reported that mindfulness meditation has a potential effect in controlling headaches, such as migraine and tension-type headache; however, its role remains controversial. This review assessed the evidence regarding the effects of mindfulness meditation for primary headache pain. METHODS: Only English databases (PubMed, Cochrane Central Register of Controlled Trials [the Cochrane Library], PsycINFO, Psychology and behavioral science collection, PsyArticles, Web of Science, and Scopus) were searched from their inception to November 2016 with the keywords ("meditation" or "mindfulness" or "vipassana" or "dzogchen" or "zen" or "integrative body-mind training" or "IBMT" or "mindfulness-based stress reduction" or "MBSR" or "mindfulness-based cognitive therapy" or "MBCT" and "Headache" or "Head pain" or "Cephalodynia" or "Cephalalgia" or "Hemicrania" or "Migraine"). Titles, abstracts, and full-text articles were screened against study inclusion criteria: controlled trials of structured meditation programs for adult patients with primary headache pain. The quality of studies included in the meta-analysis was assessed with the Yates Quality Rating Scale. The meta-analysis was conducted with Revman 5.3. RESULTS: Ten randomized controlled trials and one controlled clinical trial with a combined study population of 315 patients were included in the study. When compared to control group data, mindfulness meditation induced significant improvement in pain intensity (standardized mean difference, -0.89; 95% confidence interval, -1.63 to -0.15; P = 0.02) and headache frequency (-0.67; -1.24 to -0.10; P = 0.02). In a subgroup analysis of different meditation forms, mindfulness-based stress reduction displayed a significant positive influence on pain intensity (P < 0.000). Moreover, 8-week intervention had a significant positive effect (P < 0.000). CONCLUSIONS: Mindfulness meditation may reduce pain intensity and is a promising treatment option for patients. Clinicians may consider mindfulness meditation as a viable complementary and alternative medical option for primary headache.

Tai Chi Exercise for Patients with Chronic Heart Failure: A Meta-analysis of Randomized Controlled Trials.

AIM: This meta-analysis aimed to update and evaluate evidence from randomized controlled trials of tai chi for patients with chronic heart failure. METHOD: Both English and Chinese databases were searched from their inception to June 2, 2016 (PubMed, EMBASE, Cochrane Central Register of Controlled Trials for English publications and China Knowledge Resource Integrated, Wanfang, and Weipu databases for Chinese publication). Titles, abstracts, and full-text articles were screened against study inclusion criteria: randomized controlled trials studying tai chi intervention for patients with chronic heart failure. The meta-analysis was conducted with Revman 5.3 or STATA 12. RESULT: Thirteen randomized controlled trials were included. Tai chi induced significant improvement in 6-min walking distance (51.01 m; 30.49-71.53; P < 0.00). Moreover, tai chi was beneficial for quality of life (-10.37 points; -14.43 to -6.32; P = 0.00), left ventricular ejection fraction (7.72%; 3.58-11.89; P = 0.003), and B-type natriuretic peptide (-1.01; -1.82 to -0.19; P = 0.02). CONCLUSION: Despite heterogeneity and risk of bias, this meta-analysis further confirms that tai chi may be an effective cardiac rehabilitation method for patients with chronic heart failure. Larger, well-designed randomized controlled trials are needed to exclude the risk of bias.