Soft-shelled turtle peptide modulates microRNA profile in human gastric cancer AGS cells.

Cancer prevention using natural micronutrition on epigenetic mechanisms primarily revolves around plant extracts. However, the role of macronutrition, including animal peptides, on epigenetic modification in cancer has been elusive. In traditional Chinese medicine, the soft-shelled turtle has a long-history of being a functional food that strengthens immunity through unknown mechanisms. The present study aimed to investigate the impact of soft-shelled turtle peptide on microRNA (miRNA) expression in gastric cancer (GC) cells and to analyze the potential anticancer mechanisms for GC. Affymetrix GeneChip miRNA 3.0 Array and quantitative polymerase chain reaction were used to detect the miRNA expression profile in human GC AGS cells treated with the soft-shelled turtle peptide. The results demonstrated that 101 miRNAs (49 upregulated miRNAs and 52 downregulated miRNAs) were significantly differentially expressed in the AGS cells following soft-shelled turtle peptide treatment. Several tumor suppressor miRNAs were upregulated markedly, including miRNA-375, let-7d, miRNA-429, miRNA-148a/148b and miRNA-34a. Pathway analysis indicated that soft-shelled turtle peptide may function with anticancer properties through the Hippo signaling pathway and the forkhead box O signaling pathway. Therefore, these results demonstrated that soft-shelled turtle peptide has the capacity to influence cancer-related pathways through the regulation of miRNA expression in GC cells.

Up-Regulation of CX3CL1 via STAT3 Contributes to SMIR-Induced Chronic Postsurgical Pain.

Chronic postsurgical pain (CPSP) often occurs after surgery and has a strong impact on patients' daily lives. However, the underlying mechanism of CPSP remains unknown. Here, we used a skin/muscle incision and retraction (SMIR) model to investigate the role of CX3CL1 in SMIR-induced pain and its underlying mechanism. We found that up-regulation of CX3CL1 in the spinal dorsal horn contributed to SMIR-induced mechanical allodynia. The use of a CX3CL1-neutralizing antibody to block CX3CL1 attenuated mechanical allodynia induced by SMIR surgery. We also found that phospho-STAT3 co-localizes with CX3CL1 in spinal neurons after SMIR surgery and that this contributes to SMIR-induced mechanical allodynia. Intrathecal administration of the STAT3 inhibitor S3I-201 suppressed up-regulation of CX3CL1 at both the protein and mRNA levels after SMIR surgery. Chromatin immunoprecipitation further demonstrated that SMIR promotes the recruitment of STAT3 to the cx3cl1 gene promoter (- 1032/- 1022). These findings suggest that activation of STAT3 after SMIR mediates the up-regulation of CX3CL1, leading to mechanical allodynia, and that this upregulation may partly be due to the enhanced recruitment of STAT3 to the cx3cl1 gene promoter after SMIR.

Urinary metabolomics of complete Freund's adjuvant-induced hyperalgesia in rats.

The aim of this study was to demonstrate the differences of metabolomics changes in a hyperalgesia model and find potent biomarkers of hyperalgesia. Seven rats were placed in metabolic cages. An emulsion containing 500 µg of Complete Freund's adjuvant (CFA) was used to induce hyperalgesia. Urine samples were collected prior to the injection of CFA and on post-injection days 1, 3 and 7. Ultraperformance liquid chromatography, coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF/MS), was used for a quantitative analysis of urinary metabolic changes in the CFA-induced hyperalgesia model. Differences between the metabolic profiles of the rats in the four groups were analyzed using partial least squares discriminant analysis. Thirty-four potential urine metabolite biomarkers were identified, which changed in a trend similar to the pain threshold. These potential biomarkers were involved in 11 metabolic pathways, as follows: alanine, aspartate, and glutamate metabolism; ascorbate and aldarate metabolism; glycerolipid metabolism; glycerophospholipid metabolism; histidine metabolism; phenylalanine metabolism; sphingolipid metabolism; tryptophan metabolism; tyrosine metabolism; valine, leucine and isoleucine biosynthesis; and vitamin B6 metabolism. These results may improve our understanding of hyperalgesia and provide a basis for the clinical diagnosis of hyperalgesia.

p38 and interleukin-1 beta pathway via toll-like receptor 4 contributed to the skin and muscle incision and retraction-induced allodynia.

BACKGROUND: Persistent postsurgical pain, as an important clinical problem, seriously affects the quality of life in patients. However, the mechanism underlying persistent postsurgical pain remains largely unclear. The present study aims to elucidate the involvement of toll-like receptor 4 (TLR4) and its interaction with p38 and interleukin [IL]-1ß signaling in dorsal root ganglion (DRG) in the persistent postsurgical pain. METHODS: Skin and muscle incision and retraction (SMIR) surgery-induced paw withdrawal threshold (PWT) change was determined by applying mechanical stimuli to the plantar surface of the hind paw using von Frey hairs. The PE-10 catheter intrathecal placement was used to deliver LPS-RS, interleukin-1 receptor antagonist, or SB203580. Western blot analysis was performed to measure the expression of the TLR4, mitogen-activated protein kinases family, and IL-1ß in ipsilateral L3 and L4 DRG. Immunofluorescence staining was performed to further investigate the cell type of TLR4 expression. All data were expressed as means ± standard error of the mean and analyzed using SPSS 13.0. RESULTS: The results showed that the SMIR surgery, a rat model of persistent postoperative pain, decreased the ipsilateral 50% PWT, and the decrease lasted for at least 20 d. The expression of TLR4 and phosphorylation of p38 were upregulated in ipsilateral L3 and L4 DRG neurons after SMIR surgery. Pretreatment with LPS-RS, an established TLR4 antagonist, prevented p38 activation and attenuated mechanical allodynia induced by SMIR surgery. In addition, the expression of IL-1ß was significantly increased after SMIR surgery. Blocking IL-1ß by interleukin-1 receptor antagonist significantly improved the decreased PWT evoked by SMIR. Moreover, inhibition of TLR4 or p38 pathway prevented the IL-1ß upregulation and mechanical allodynia induced by SMIR. CONCLUSIONS: These findings suggest that the activation of p38 and IL-1ß signaling pathway via TLR4 mediate mechanical allodynia after SMIR surgery.