Multiple Mild Stimulations Reduce Membrane Distribution of CX3CR1 Promoted by Annexin a1 in Microglia to Attenuate Excessive Dendritic Spine Pruning and Cognitive Deficits Caused by a Transient Ischemic Attack in Mice / 神经科学通报·英文版

A transient ischemic attack (TIA) can cause reversible and delayed impairment of cognition, but the specific mechanisms are still unclear. Annexin a1 (ANXA1) is a phospholipid-binding protein. Here, we confirmed that cognition and hippocampal synapses were impaired in TIA-treated mice, and this could be rescued by multiple mild stimulations (MMS). TIA promoted the interaction of ANXA1 and CX3CR1, increased the membrane distribution of CX3CR1 in microglia, and thus enhanced the CX3CR1 and CX3CL1 interaction. These phenomena induced by TIA could be reversed by MMS. Meanwhile, the CX3CR1 membrane distribution and CX3CR1-CX3CL1 interaction were upregulated in primary cultured microglia overexpressing ANXA1, and the spine density was significantly reduced in co-cultured microglia overexpressing ANXA1 and neurons. Moreover, ANXA1 overexpression in microglia abolished the protection of MMS after TIA. Collectively, our study provides a potential strategy for treating the delayed synaptic injury caused by TIA.

Involvement of NF-κB and the CX3CR1 Signaling Network in Mechanical Allodynia Induced by Tetanic Sciatic Stimulation / 神经科学通报·英文版

Tetanic stimulation of the sciatic nerve (TSS) triggers long-term potentiation in the dorsal horn of the spinal cord and long-lasting pain hypersensitivity. CX3CL1-CX3CR1 signaling is an important pathway in neuronal-microglial activation. Nuclear factor κB (NF-κB) is a key signal transduction molecule that regulates neuroinflammation and neuropathic pain. Here, we set out to determine whether and how NF-κB and CX3CR1 are involved in the mechanism underlying the pathological changes induced by TSS. After unilateral TSS, significant bilateral mechanical allodynia was induced, as assessed by the von Frey test. The expression of phosphorylated NF-κB (pNF-κB) and CX3CR1 was significantly up-regulated in the bilateral dorsal horn. Immunofluorescence staining demonstrated that pNF-κB and NeuN co-existed, implying that the NF-κB pathway is predominantly activated in neurons following TSS. Administration of either the NF-κB inhibitor ammonium pyrrolidine dithiocarbamate or a CX3CR1-neutralizing antibody blocked the development and maintenance of neuropathic pain. In addition, blockade of NF-κB down-regulated the expression of CX3CL1-CX3CR1 signaling, and conversely the CX3CR1-neutralizing antibody also down-regulated pNF-κB. These findings suggest an involvement of NF-κB and the CX3CR1 signaling network in the development and maintenance of TSS-induced mechanical allodynia. Our work suggests the potential clinical application of NF-κB inhibitors or CX3CR1-neutralizing antibodies in treating pathological pain.

Intervention and therapeutic effect of siRNA-HDAC5 on abnormal histone modification in non-obese diabetic mice / 中南大学学报(医学版)

OBJECTIVE@#To evaluate therapeutic eff ect of siRNA-HDAC5 on non-obese diabetic (NOD) mice by using small interference RNA (siRNA) technique to knock down the expression of HDAC5 in spleen CD4+ T cells.@*METHODS@#NOD mice, 12-weeks old, were randomly divided into 3 groups and were given normal saline, siRNA-Control or siRNA-HDAC5 through caudal vein injection. The spleens and other samples were collected at the 18th, 24th or 30th week. The blood glucose was tested by blood glucose meter. The urinary albumin and serum levels of IL-1, IL-6, IL-18, and TNF-α were detected by ELISA. The mRNA levels of CD11a, CCR5, and CX3CR1 in spleen CD4+ T cells were measured by quantitative Real-time PCR. The HDAC5 protein level in spleen CD4+ T cell was detected by Western blot.@*RESULTS@#Compared with the control group, the siRNA-HDAC5 group showed a significant decrease in blood glucose, urine albumin excretion rate, serum cytokine and the mRNA levels of CD11a, CCR5, and CX3CR1, consist with the decrease in protein level of HDAC5.@*CONCLUSION@#Inhibition of HDAC5 expression in NOD mice could effectively alleviate the onset and development of kidney damage caused by diabetes.

Effects of curcumin on pain threshold and on the expression of nuclear factor κ B and CX3C receptor 1 after sciatic nerve chronic constrictive injury in rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of curcumin on pain threshold and the expressions of nuclear factor κ B (NF-κ B) and CX3C chemokine receptor 1 (CX3CR1) in spinal cord and dorsal root ganglion (DRG) of the rats with sciatic nerve chronic constrictive injury.</p><p><b>METHODS</b>One hundred and twenty male Sprague Dawley rats, weighing 220-250 g, were randomly divided into 4 groups. Sham surgery (sham) group: the sciatic nerves of rats were only made apart but not ligated; chronic constrictive injury (CCI) group: the sciatic nerves of rats were only ligated without any drug treatment; curcumin treated injury (Cur) model group: the rats were administrated with curcumin 100 mg/(kg·d) by intraperitoneal injection for 14 days after CCI; solvent control (SC) group: the rats were administrated with the solvent at the same dose for 14 days after CCI. Thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) of rats were respectively measured on pre-operative day 2 and postoperative day 1, 3, 5, 7, 10 and 14. The lumbar segment L4-5 of the spinal cord and the L4, L5 DRG was removed at post-operative day 3, 7 and 14. The change of nuclear factor κ B (NF-κ B) p65 expression was detected by Western blotting while the expression of CX3CR1 was determined by immunohistochemical staining.</p><p><b>RESULTS</b>Compared with the sham group, the TWL and MWT of rats in the CCI group were significantly decreased on each post-operative day (P<0.01), which reached a nadir on the 3rd day after CCI, and the expressions of NF-κ B p65 and CX3CR1 were markedly increased in spinal cord dorsal horn and DRG. In the Cur group, the TWL of rats were significantly increased than those in the CCI group on post-operative day 7, 10 and 14 (P<0.05) and MWT increased than those in the CCI group on post-operative day 10 and 14 (P<0.05). In addition, the administration of curcumin significantly decreased the positive expressions of NF-κ B p65 and CX3CR1 in spinal cord and DRG (P<0.05).</p><p><b>CONCLUSION</b>Our study suggests that curcumin could ameliorate the CCI-induced neuropathic pain, probably through inhibiting CX3CR1 expression by the activation of NF-κ B p65 in spinal cord and DRG.</p>

Curcumin down-regulates CX3CR1 expression in spinal cord dorsal horn and DRG in neuropathic pain rats / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effects of curcumin on the behavior of chronic constrictive injury (CCI) rats and the CX3CR1 expression in spinal cord dorsal horn and dorsal root ganglia (DRG).</p><p><b>METHOD</b>Seventy-two male SD rats were randomly divided into 4 groups: 1) Sham operation group (Sham); 2) Chronic constrictive injury group (CCI); 3) Curcumin treated group (Cur), administrated with curcumin 100 mg x kg(-1) x d(-1) ip for 14 days after CCI; 4) Solvent contrast group (SC), administrated with an equal volume of solvent for 14 days after CCI. Paw thermal withdrawal (PTWL) and paw mechanical withdrawal threshold (PMWT) were measured on 2 pre-operative and 1, 3, 5, 7, 10, 14 post-operative days respectively. The lumbar segments L4-5 of the spinal cord and the L4, L5 DRG were removed at 3, 7, 14 days after surgery. The expression of CX3CR1 was determined by immunohistochemical staining.</p><p><b>RESULT</b>Compared with Sham group, PTWL and PMWT in CCI group were significantly lower on each post-operative day (P<0.01), which reached a nadir on the 3rd day after CCI (PTWL was 6.5 +/- 1.1, PMWT was 22.6 +/- 5.1), and the expression of CX3CR1 were markedly increased in spinal cord dorsal horn and DRG. In Cur group, PTWL were higher than in CCI group on 7, 10, 14 post-operative day (P<0.05), and PMWT were higher than those in CCI group on 10 and 14 post-operative day (P<0.05). The administration of curcumin could significantly attenuate the activation of CX3CR1 induced by CCI.</p><p><b>CONCLUSION</b>The study suggests that curcumin ameliorates the CCI-induced neuropathic pain, probably by attenuating the expression of CX3CR1 in spinal cord dorsal horn and dorsal root ganglia.</p>

mRNA expression of chemokine receptors on peripheral blood mononuclear cells and correlation with clinical features in systemic lupus erythematosus patients / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the expressions of chemokine receptors and interleukin (IL) receptors on the peripheral blood mononuclear cells (PBMCs) from systemic lupus erythematosus (SLE) patients and their correlations with clinical features as well as SLE disease activity index (SLEDAI).</p><p><b>METHODS</b>The mRNA expressions of chemokine receptors and IL receptors on PBMCs of 93 SLE patients and 30 healthy controls were detected by reverse transcription-polymerase chain reaction, including CCR2, CCR3, CCR4, CCR5, CCR6, CCR8, CXCR3, CXCRS, CX3CR1, XCR1, IL-4R, and IL-10R. The clinical features of SLE patients were recorded. The correlations of chemokine receptors and IL receptors mRNA expressions with clinical features as well as SLEDAI were assayed using linear regression analysis.</p><p><b>RESULTS</b>The level of CCR5 mRNA in SLE patients (including active and inactive SLE) was significantly higher than that in healthy controls (P < 0.05), and there was no significant difference between active and inactive patients in this respect (P > 0.05). CX3CR1 mRNA expression significantly increased from healthy control to inactive SLE to active SLE in sequence. The others (except for CCR8, CXCR3, and IL-10R) in active SLE patients were significantly higher than those in both inactive SLE patients and healthy controls (all P < 0.05). There were positive correlations between SLEDAI and CCR2 (r = 0.424, t = 4.313, P < 0.001), CCR3 (r = 0.518, t = 5.410, P < 0.001), CCR4 (r = 0.376, t = 3.851, P < 0.001), CCR6 (r = 0.457, t = 4.513, P < 0.001), CXCR5 (r = 0.455, t = 4.629, P < 0.001), CX3CR1 (r = 0.445, t = 4.523, P < 0.001), as well as XCR1 (r = 0.540, t = 5.445, P < 0.001). And CCR5 mRNA expression level was positively correlated with IL-4R mRNA (r = 0.313, t = 2.353, P < 0.05). The patients with myositis and cutaneous vasculitis simultaneously showed lower levels of CCR5 and CX3CR1, and CCR5 expression was negatively correlated with the scores of SLEDAI in SLE cases accompanied by photosensitivity (r = 0.426, t = -2.155, P < 0.05).</p><p><b>CONCLUSION</b>Increased expressions of CCR5 and CX3CR1 on PBMCs may be indicators in clinical survey for SLE.</p>

Regulation of inflammatory pain by NF-κB and CX3CR1 at the spinal cord of rats / 中南大学学报(医学版)

OBJECTIVE@#To observe the effect of intrathecal injection of nuclear factor-κB (NF-κB) inhibitor of pyrrolidine dithiocarbamate (PDTC) on pain sensitivity thresholds and the expression of spinal cord CX3C chemokine receptor 1 (CX3CR1) in monoarthritis (MA) model in rats.@*METHODS@#Forty-eight Sprague-Dawley rats were randomly divided into 4 groups (12 each) after successful intrathecal catheterization: (1) sham operation with physiological saline group (the sham group); (2) MA with normal saline group (the MA group); (3) 10 μL 100 μmol/L PDTC before MA (the PDTC pre-treatment group); (4)MA before 10 μL 100 μmol/L PDTC (the PDTC post-treatment group). Normal saline or PDTC was injected 5 d after the intrathecal catheterization. Pain sensitivity thresholds were measured in the 4 groups before and after the intrathecal injection at different time points. Rat monoarthritis model was subsequently built by injecting complete Freund's adjuvant (CFA) into the left ankle joint of the rats. On day 3 after the intrathecal injection, expression of microglia in the L₅ spinal cord segment was observed by immunohistochemical method, and the lumbar segments L₄-L₅ of spinal cord were taken to perform RT-PCR to examine the expression of NF-κB mRNA and CX3CR1 mRNA.@*RESULTS@#Compared with the MA group, the pain sensitivity thresholds in the sham group, the PDTC pre-treatment group and the PDTC post-treatment group at each time point after the intrathecal injection increased significantly (P<0.05), while microglia in the L₅ spinal cord segment decreased significantly (P<0.05) and expression of CX3CR1 mRNA and NF-κB mRNA in the lumbar segments L₄-L₅ of spinal cord decreased significantly (P<0.05).@*CONCLUSION@#The hyperalgesic effect of the CFA-induced model of monoarthritis can be relieved by intrathecal injection of NF-κB inhibitor PDTC. Its mechanism is possibly related to NF-κB signal pathway which is involved in the formation of inflammatory pain through regulating CX3CR1 expression.

Effect of simvastatin on monocyte CX3CR1 expression in patients with acute coronary syndrome / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of simvastatin on expression of CX3CR1 in the monocytes in patients with acute coronary syndrome and investigate the non-lipid mechanisms of statins against atherosclerosis.</p><p><b>METHODS</b>The expression of CX3CR1 in the monocytes was measured by quantitative real-time RT-PCR in 63 patients with acute coronary syndrome confirmed by coronary arteriography after treatment with simvastatin at 10(-7) approximately 10(-5) mol/L for 4, 8 and 12 h, respectively.</p><p><b>RESULTS</b>CX3CR1 expression in the monocytes treated with different concentrations of simvastatin was significantly lower than that in the control cells (P<0.05), and the expression in the cells treated with the agent for different time lengths was also significantly lower than that in the control cells (P<0.01).</p><p><b>CONCLUSION</b>Simvastatin can reduce CX3CR1 expression in the monocytes of the patients with acute coronary syndrome in a concentration- and time-dependent manner, so as to reduce the inflammation and stabilize the vascular plaques.</p>

Distribution of HIV-1 coreceptor CX3CR1 allelic polymorphisms in general population, HIV-1 high-risk group and HIV-1 carriers of Chinese indigenous Han and Uygur people / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the V249I and T280M allelic polymorphisms of human immunodeficiency virus (HIV) coreceptor CX3CR1 in HIV-1 infected and uninfected population of Chinese indigenous Han and Uygur people and to probe the association between I249-M280 haplotype and HIV-1 susceptibility as well as AIDS progression.</p><p><b>METHODS</b>Genomic DNA of 223 Uygur subjects and 316 Han subjects were purified from PBMC. I249 and M280 allelic frequencies were identified by polymerase chain reaction (PCR)/nest polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. All data were tested by chi(2) or u statistics analysis.</p><p><b>RESULTS</b>Allelic frequencies of I249 and M280 were 16.1% and 13.3% in Uygur people, and 3.3% and 2.4% in Han people. No obvious difference existed between three groups of either ethnic group. However the allelic frequencies of HIV infected population were higher than those of general population, and those of general population higher than those of HIV-1 high-risk group. There was a strong linkage between I249 and M280 (P almost zero).</p><p><b>CONCLUSIONS</b>I249 mutation was the sine qua non of M280 mutation, and most I249 alleles were accompanied by M280. The frequency of I249-M280 haplotype in Uygur population (13.3%) was adjacent to Caucasian people (15.8%), and that of I249-T280 haplotype (2.8%) was obviously lower than Caucasian people (12.5%); while both of them in Han people were much lower (0.9% and 2.4%). I249-M280 haplotype could accelerate AIDS progression according to Faure et al, while might be associated with HIV-1 susceptibility.</p>

Expression of fractalkine and its receptor in acute cardiac allografts rejection / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the expression of fractalkine (FKN) and its receptor CX3CR1 in cardiac allografts and the effect of Cyclosporin A (CsA).</p><p><b>METHODS</b>Three groups of rats underwent heterotopic cardiac transplantation, 45 cases in each group and 5 cases in control group: SD to SD regarded as isograft group (group A), Wistar to SD divided into CsA untreated allograft group (group B) and CsA treated allograft group (group C), normal SD rats as control group. The FKN mRNA expression was detected by one-step RT-PCR method and the expression of FKN and CX3CR1 protein was detected by standard ABC immunohistochemical technique.</p><p><b>RESULTS</b>The expression of FKN mRNA and protein was weak in both isografts and normal heart specimens. The changes of FKN mRNA expression were correlated with the process of acute allograft rejection. The peak of FKN mRNA expression (0.8 +/- 0.26) appeared on the seventh day after transplantation, which could be down-regulated by CsA significantly (t = 2.390, P < 0.05). FKN protein was located in endothelia cells and its receptor CX3CR1 was located in infiltrating mononuclear cells in allografts.</p><p><b>CONCLUSIONS</b>Upregulation of FKN and its receptor was significantly correlated with the trafficking of mononuclear cells which play an important role in acute allograft rejection. It may be one of the important mechanisms of CsA to intervene the acute rejection by inhibiting the activation of the FKN-CX3CR1 pathway.</p>