TREM-2 Drives Development of Multiple Sclerosis by Promoting Pathogenic Th17 Polarization / 神经科学通报·英文版

Multiple sclerosis (MS) is a neuroinflammatory demyelinating disease, mediated by pathogenic T helper 17 (Th17) cells. However, the therapeutic effect is accompanied by the fluctuation of the proportion and function of Th17 cells, which prompted us to find the key regulator of Th17 differentiation in MS. Here, we demonstrated that the triggering receptor expressed on myeloid cells 2 (TREM-2), a modulator of pattern recognition receptors on innate immune cells, was highly expressed on pathogenic CD4-positive T lymphocyte (CD4+ T) cells in both patients with MS and experimental autoimmune encephalomyelitis (EAE) mouse models. Conditional knockout of Trem-2 in CD4+ T cells significantly alleviated the disease activity and reduced Th17 cell infiltration, activation, differentiation, and inflammatory cytokine production and secretion in EAE mice. Furthermore, with Trem-2 knockout in vivo experiments and in vitro inhibitor assays, the TREM-2/zeta-chain associated protein kinase 70 (ZAP70)/signal transducer and activator of transcription 3 (STAT3) signal axis was essential for Th17 activation and differentiation in EAE progression. In conclusion, TREM-2 is a key regulator of pathogenic Th17 in EAE mice, and this sheds new light on the potential of this therapeutic target for MS.

Effect of electroacupuncture on expression of p-ERK and p-CREB in the spinal dorsal horn of diabetic neuropathic pain rats / 中华物理医学与康复杂志

Objective:To observe any effect of electroacupuncture (EA) on the expression of phosphorylated extracellular signal-regulated protein kinase (p-ERK1/2) and phosphorylated cyclic adenosine monophosphate response element binding protein (p-CREB) in the spinal dorsal horns of diabetics experiencing neuropathic pain.Methods:Eight rats were randomly selected from 30 healthy male Sprague-Dawley rats as the normal group (N), and the remaining twenty-two rats were treated with a single high-dose intraperitoneal injection of streptozotocin (STZ) to establish a neuropathic pain model. The rats modeled successfully were randomly divided into a model group (M, n=8) and an EA group ( n=8). In the EA group, electroacupuncture was applied at the bilateral Hou san li and Kunlun acupoints starting on the 15th day after the STZ injection. The daily sessions lasted 30 minutes for 1 week. Body weight (BW), fasting blood glucose (FBG) and paw withdrawal latency (PWL) were observed before the STZ injection and on the 7th, 14th, and 21st days afterward. The expression of p-ERK1/2 and p-CREB in the dorsal horns of the rats′ spinal cords was detected using western blotting. The count of p-CREB-positive cells in the dorsal horns and their co-localization with neurons was detected using immunofluorescence. Results:In comparison with the N group, the average BW of the M group on the 7th, 14th and 21st days after the STZ injection was significantly lower, while the average FBG was significantly higher. There was no significant difference between the M and N groups in the average PWL on the 7th day after the STZ injection, but it had decreased significantly in the M group on the 14th and 21st days. Compared with the M group, the average PWL of the EA group was significantly longer on the 21st day after the injection. The expression of p-ERK1/2 and p-CREB protein in the spines of the M group was significantly higher than in the N group. p-CREB positive cells were more numerous in the M group compared with the N group, while in the EA group they were fewer. P-CREB was co-located with neurons in the spinal dorsal horn.Conclusion:EA can alleviate neuropathic pain effectively, perhaps by inhibiting the expression of p-ERK1/2 and p-CREB in the dorsal horns of the spinal cord.