Effect of electroacupuncture and pretreatment of electroacupuncture on pain sensitization and expression of P2X7R in spinal dorsal horn in rats with diabetic neuropathic pain / 中国针灸

OBJECTIVE@#To observe the occurrence time of neuralgia and the expression of purinergic ligand-gated ion channel 7 receptor (P2X7R) in the dorsal horn of the spinal cord after intraperitoneal injection of streptozotocin (STZ) in diabetic rats, and to explore the effect of electroacupuncture (EA) and pretreatment of EA on the heat pain threshold and expression of P2X7R in the spinal dorsal horn in rats with diabetic neuropathic pain (DNP), and to explore the possible mechanism of EA for DNP.@*METHODS@#PartⅠ: Thirty male SD rats were randomly selected from 64 male SD rats as the control group; the remaining rats were given intraperitoneal injection of STZ (10 mg/mL) at a dose of 65 mg/kg to establish the diabetes model, and 30 rats were successfully modeled as the model group. The control group and the model group were divided into three subgroups respectively at 7, 14 and 21 days, with 10 rats in each subgroup. Body mass, fasting blood glucose (FBG) and thermal pain threshold were recorded at 7, 14 and 21 days after injection; the expression of P2X7R in spinal dorsal horn was detected by Western blot. PartⅡ: Eight SD rats were randomly selected from 35 male SD rats as the blank group, and the remaining 27 rats were given intraperitoneal injection of STZ (10 mg/mL) at a dose of 65 mg/kg to establish the diabetes model. The 24 rats with successful diabetes model were randomly divided into a DNP group, an EA group and a pre-EA group, 8 rats in each group. Fifteen to 21 days after STZ injection, the EA group received EA at "Zusanli" (ST 36) and "Kunlun" (BL 60), continuous wave, frequency of 2 Hz, 30 min each time, once a day; the intervention method in the pre-EA group was the same as that in the EA group. The intervention time was 8 to 14 days after STZ injection. The body mass, FBG and thermal pain threshold were recorded before STZ injection and 7, 14 and 21 days after STZ injection; the expression of P2X7R in spinal dorsal horn was detected by Western blot 21 days after injection.@*RESULTS@#PartⅠ: Compared with the control group, in the model group, the body mass was decreased and FBG was increased 7, 14 and 21 days after STZ injection (P<0.01), and the thermal pain threshold was decreased 14 and 21 days after STZ injection (P<0.05), and the expression of P2X7R in spinal dorsal horn was increased 7, 14 and 21 days after STZ injection (P<0.05, P<0.01). PartⅡ: Compared with the blank group, in the DNP group, the body mass was decreased and fasting blood glucose were increased 7, 14 and 21 days after STZ injection (P<0.01). Compared with the DNP group, in the pre-EA group, the heat pain threshold was increased 14 and 21 days after STZ injection (P<0.05), while in the EA group, the heat pain threshold was increased 21 days after STZ injection (P<0.01), and the expression of P2X7R in the dorsal horn in the EA group and the pre-EA group was decreased (P<0.01).@*CONCLUSION@#The diabetic neuropathic pain is observed 14 days after STZ injection. EA could not only treat but also prevent the occurrence of DNP, and its mechanism may be related to down-regulation of P2X7R expression in the dorsal horn of the spinal cord.

Involvement of moesin phosphorylation in ischemia/reperfusion induced inner blood-retinal barrier dysfunction.

AIM: To investigate the role of moesin and its underlying signal transduction in retinal vascular damage induced by retinal ischemia-reperfusion (RIR) insult. METHODS: C57BL/6 mice were subjected to continued ischemia for 45min, followed by blood reperfusion. The expression and phosphorylation of moesin in retinal vessels were detected by immunohistochemistry and Western blotting. The inner blood-retinal barrier was evaluated using FITC-dextran leakage assay on whole-mount retina. Further studies were conducted to explore the effects of p38 mitogen-activated protein kinase (MAPK) pathway on the involvement of moesin in RIR-evoked retinal vascular hyperpermeability response. RESULTS: It revealed that RIR induced moesin phosphorylation in a time-dependent manner after reperfusion. The phosphorylation of moesin was alleviated by inhibitions of p38 MAPK, while this treatment also ameliorated the dysfunction of inner blood-retinal barrier. CONCLUSION: The results suggest that moesin is involved in RIR-evoked retinal vascular endothelial dysfunction and the phosphorylation of moesin is triggered via p38 MAPK activation.

Involvement of Advanced Glycation End Products in the Pathogenesis of Diabetic Retinopathy.

Diabetic retinopathy (DR) is a common and devastating microvascular complication of diabetes and a major cause of acquired blindness in young adults. Advanced glycation end products (AGEs) accumulated under hyperglycemic conditions are thought to play an important role in the pathogenesis of DR. AGEs can exert their deleterious effects by acting directly to induce aberrant crosslinking of extracellular matrix proteins, to increase vascular stiffness, altering vascular structure and function. Moreover, AGEs binding to the receptor for AGEs (RAGE) evokes intensive intracellular signaling cascades that leading to endothelial dysfunction, elaboration of key proinflammatory cytokines and proangiogenic factors, mediating pericyte apoptosis, vascular inflammation and angiogenesis, as well as breakdown of the inner blood-retinal barrier (BRB), the end result of all these events is damage to the neural and vascular components of the retina. Elucidation of AGE-induced mechanisms will help in the understanding of the complex cellular and molecular pathogenesis associated with DR. Novel anti-AGEs agents or AGE crosslink "breakers" are being investigated, it is hoped that in next few years, some of these promising therapies will be successfully applied in clinical context, aiming to reduce the major economical and medical burden caused by DR.

[Surgical correction of conjunctival sac narrowing after orbital implantation using polyester fiber heart patches].

OBJECTIVE: To test the feasibility of correcting conjunctival sac narrowing following orbital implantation using polyester fiber heart patches instead of the skin autograft. METHODS: Twelve patients of conjunctival sac narrowing after orbital implantation (including 3 with orbital implant exposure) admitted in Nanfang Hospital between 2012 and 2016 received surgical correction of the conjunctival sac using polyester fiber heart patches. During the surgery, the central conjunctival sac was opened, the exposed area was covered with suitable polyester fiber heart patches, and the palpebral margin was sutured. RESULTS: Three months after the operation, 10 patients showed improved appearance after implantation of the prosthetic eye. Two patients received a second operation to remove the patches due to graft rejection and infections and skin autograft was implanted for reconstruction of the conjunctival sac. CONCLUSION: Polyester fiber heart patches are ideal materials for repairing Conjunctival sac narrowing and orbital implant exposure, but this approach is not suitable in cases of severe narrowing or occlusion of the conjunctival sac.

[The role and mechanism of costimulatory molecule B7-H3 in the immune reaction of corneal transplantation in mice].

OBJECTIVE: To investigate the role of B7-H3 in the immune reaction of corneal transplantation in mice METHODS: Experimental study. Thirty Corneas of C57BL/6 mice were orthotopically transplanted into the eyes of BALB/c mice, and graft survival was assessed on the basis of Sonoda's standard. When the RI grade was ≥ 2, rejection was acknowledged and brought into the rejected group(R), and the others into the accepted group (A); 8 BALB/c Corneas into their own eyes belonged to isografts (I) ; In addition, 8 normal BALB/c mice were the control group (C) . At last, three eyes in each group (C, I, A, R groups) were used for HE staining and IHC of B7-H3, and there were five eyes in each group for qPCR to detect B7-H3 mRNA expression. Repeated-measures analysis of variance (factorial analysis) followed by LSD test were used for post hoc analysis for expression differences of B7-H3 mRNA between groups. RESULTS: There were 9 accepted grafts and 21 rejected grafts in 30 mice, and transplantation survival rate was 30% in the allograft group, while all grafts were transparent, and transplantation survival rate was 100% in the isografts. IHC results showed that B7-H3 was expressed on the corneal epithelium, endothelium and iris-ciliary body of both normal corneas and Isografts; B7-H3 expression increased in the accepted group and decreased in the rejected group . The results of qPCR conformed to the IHC; Repeated-measures analysis of variance (factorial analysis) followed by LSD test were used for post hoc analysis for differences between groups (F = 429.546) . there was a low B7-H3 mRNA expression in the R group (3.89 ± 0.037) and high expression in the A group (5.04 ± 0.058); and C (4.30 ± 0.023) ,I (4.33 ± 0.031) groups had no significant difference (P = 0.387) ;But there was a significant difference between group R and C (P = 0.003)or group A and C(P = 0.001). CONCLUSION: All above show that B7-H3 may play an important role in the maintenance of ocular immune privilege.