Electroacupuncture Alleviates Mechanical Allodynia in a Rat Model of Complex Regional Pain Syndrome Type-I via Suppressing Spinal CXCL12/CXCR4 Signaling.

Complex regional pain syndrome (CRPS) results in chronic and excruciating pain in patients. Conventional therapies lack effectiveness, rendering it one of the most difficult to treat neurological conditions.. Electroacupuncture (EA) is an effective alternative therapy for pain relief. Here, we investigated whether EA exerts analgesic effect on a rat model of CRPS type-I (CRPS-I) and related mechanisms. The rat chronic postischemic pain (CPIP) model was established to mimic CRPS-I. 100Hz EA exerted robust and persistent antiallodynic effect on CPIP model compared with 2 Hz EA or sham EA. EA markedly suppressed the overexpression of CXCL12/CXCR4 in spinal cord dorsal horn (SCDH) of CPIP model, leading to substantial decrease in neuronal and glial cell activities in SCDH. Pharmacological blocking CXCR4 mimicked EA-induced antiallodynic effect and related cellular events in SCDH, whereas exogenous CXCL12 abolished EA's effect. CXCR4 signaling resulted in ERK activation in SCDH, contributing to mechanical allodynia of CPIP model rats, whereas EA markedly reduced ERK activation. Therefore, we demonstrated that EA interferes with CXCL12/CXCR4 signaling in SCDH and downstream ERK pathway to exert robust antiallodynic effect on an animal model of CRPS-I. Our work suggests that EA may be a potential therapeutic option for CRPS-I in clinic. PERSPECTIVE: Our work identified that EA exerts robust antiallodynic effect on an animal model of CRPS-I, via mechanisms involving inhibition of CXCL12/CXCR4 signaling. EA further attenuates downstream neuronal and glial cell activation and ERK pathway in SCDH. This work suggests that EA may be a potential therapeutic option for CRPS-I management in clinic.

Effects of Horticultural Therapy on Asian Older Adults: A Randomized Controlled Trial.

The effect of horticultural therapy (HT) on immune and endocrine biomarkers remains largely unknown. We designed a waitlist-control randomized controlled trial to investigate the effectiveness of HT in improving mental well-being and modulating biomarker levels. A total of 59 older adults was recruited, with 29 randomly assigned to the HT intervention and 30 to the waitlist control group. The participants attended weekly intervention sessions for the first 3 months and monthly sessions for the subsequent 3 months. Biological and psychosocial data were collected. Biomarkers included IL-1ß, IL-6, sgp-130, CXCL12/SDF-1α, CCL-5/RANTES, BDNF (brain-derived neurotrophic factor), hs-CRP, cortisol and DHEA (dehydroepiandrosterone). Psychosocial measures examined cognitive functions, depression, anxiety, psychological well-being, social connectedness and satisfaction with life. A significant reduction in plasma IL-6 level (p = 0.02) was observed in the HT intervention group. For the waitlist control group, significant reductions in plasma CXCL12 (SDF-1α) (p = 0.003), CXCL5 (RANTES) (p = 0.05) and BDNF (p = 0.003) were observed. A significant improvement in social connectedness was also observed in the HT group (p = 0.01). CONCLUSION: HT, in reducing plasma IL-6, may prevent inflammatory disorders and through maintaining plasma CXCL12 (SDF-1α), may maintain hematopoietic support to the brain. HT may be applied in communal gardening to enhance the well-being of older adults.

Chemotherapeutic agents attenuate CXCL12-mediated migration of colon cancer cells by selecting for CXCR4-negative cells and increasing peptidase CD26.

BACKGROUND: Recurrence of colorectal cancer (CRC) may arise due to the persistence of drug-resistant and cancer-initiating cells that survive exposure to chemotherapy. Proteins responsible for this recurrence include the chemokine receptor CXCR4, which is known to enable CRC metastasis, as well as the cancer-initiating cell marker and peptidase CD26, which terminates activity of its chemokine CXCL12. METHODS: We evaluated the expression and function of CXCR4 and CD26 in colon cancer cell lines and xenografts following treatment with common chemotherapies using radioligand binding, flow cytometry, immunofluorescence, and enzymatic assays. RESULTS: 5-Fluorouracil, oxaliplatin and SN-38 (the active metabolite of irinotecan), as well as cisplatin, methotrexate and vinblastine, each caused decreases in cell-surface CXCR4 and concomitant increases in CD26 on HT-29, T84, HRT-18, SW480 and SW620 CRC cell lines. Flow cytometry indicated that the decline in CXCR4 was associated with a significant loss of CXCR4+/CD26- cells. Elevations in CD26 were paralleled by increases in both the intrinsic dipeptidyl peptidase activity of CD26 as well as its capacity to bind extracellular adenosine deaminase. Orthotopic HT-29 xenografts treated with standard CRC chemotherapeutics 5-fluorouracil, irinotecan, or oxaliplatin showed dramatic increases in CD26 compared to untreated tumors. Consistent with the loss of CXCR4 and gain in CD26, migratory responses to exogenous CXCL12 were eliminated in cells pretreated with cytotoxic agents, although cells retained basal motility. Analysis of cancer-initiating cell CD44 and CD133 subsets revealed drug-dependent responses of CD26/CD44/CD133 populations, suggesting that the benefits of combining standard chemotherapies 5-fluoruracil and oxaliplatin may be derived from their complementary elimination of cell populations. CONCLUSION: Our results indicate that conventional anticancer agents may act to inhibit chemokine-mediated migration through eradication of CXCR4+ cells and attenuation of chemokine gradients through elevation of CD26 activity.

Inhibitory effect of triptolide on lymph node metastasis in patients with non-Hodgkin lymphoma by regulating SDF-1/CXCR4 axis in vitro.

AIM: To investigate the antiproliferative effect of triptolide on B-NHL cell line Raji cells, to study its effect on lymph node metastasis in patients with non-Hodgkin's lymphoma (NHL) in vitro, and to explore the underlying mechanism regulating SDF-1/CXCR4 axis. METHODS: The effects of triptolide on the growth of Raji cells were studied by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay. The effects of triptolide on SDF-1 mRNA expression in lymph node stromal cells from patients with NHL were determined by reverse transcriptase-polymerase chain reaction (RT-PCR). The effects of triptolide on CXCR4 expression on lymphoma cells freshly isolated from the lymph nodes of these patients were studied by flow cytometric analysis. Chemotaxis assays were performed to observe the effects of triptolide on migration of primary lymphoma cells towards recombinant human SDF-1 alpha (rhSDF-1 alpha) or cultured lymph node stromal cells in vitro. RESULTS: Triptolide inhibited the proliferation of B-NHL cell line Raji cells in a dose- and time-dependent manner with a 24-h IC50 value of 43.06 nmol/L and a 36-h IC50 value of 25.08 nmol/L. The expression of SDF-1alpha mRNA in lymph node stromal cells obtained from patients with NHL was decreased after treatment by triptolide at concentrations of 25 and 50 nmol/L for 24 h. Flow cytometry analysis showed that the CXCR4 expression on primary lymphoma cells were downregulated gradually in a dose-dependent manner following triptolide treatment. Chemotaxis assays revealed that the migration of freshly isolated lymphoma cells towards either rhSDF-1 or cultured lymph node stromal cells was markedly inhibited by the addition of triptolide in vitro, and the inhibition was dose-dependent. CONCLUSION: Triptolide can inhibit the proliferation of B-NHL cell line Raji cells. Moreover, triptolide is able to inhibit the migration of lymphoma cells via lymph nodes in vitro. The potential antitumor mechanisms of triptolide are related to the antiproliferative effect and the blockage of SDF-1/CXCR4 axis.