Based on the CX3C chemokine ligand 1(CX3CL1)-CX3C chemokine receptor 1(CX3CR1) axis, this study explored the potential mechanism by which Zuogui Jiangtang Jieyu Formula(ZGJTJY) improved neuroinflammation and enhanced neuroprotective effect in a rat model of diabetes mellitus complicated with depression(DD). The DD rat model was established by feeding a high-fat diet combined with streptozotocin(STZ) intraperitoneal injection for four weeks and chronic unpredictable mild stress(CUMS) combined with isolated cage rearing for five weeks. The rats were divided into a control group, a model group, a positive control group, an inhibitor group, and a ZGJTJY group. The open field test and forced swimming test were used to assess the depression-like behaviors of the rats. Enzyme-linked immunosorbent assay(ELISA) was performed to measure the expression levels of the pro-inflammatory cytokines interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α) in plasma. Immunofluorescence staining was used to detect the expression of ionized calcium-binding adapter molecule 1(Iba1), postsynaptic density protein-95(PSD95), and synapsin-1(SYN1) in the hippocampus. Hematoxylin-eosin(HE) staining, Nissl staining, and TdT-mediated dUTP nick end labeling(TUNEL) fluorescence staining were performed to assess hippocampal neuronal damage. Western blot was used to measure the expression levels of CX3CL1, CX3CR1, A2A adenosine receptor(A2AR), glutamate receptor 2A(NR2A), glutamate receptor 2B(NR2B), and brain-derived neurotrophic factor(BDNF) in the hippocampus. Compared with the model group, the ZGJTJY group showed improved depression-like behaviors in DD rats, enhanced neuroprotective effect, increased expression of PSD95, SYN1, and BDNF(P<0.01), and decreased expression of Iba1, IL-1β, and TNF-α(P<0.01), as well as the expression of CX3CL1, CX3CR1, A2AR, NR2A, and NR2B(P<0.01). These results suggest that ZGJTJY may exert its neuroprotective effect by inhibiting the CX3CL1-CX3CR1 axis and activation of hippocampal microglia, thereby improving neuroinflammation and abnormal activation of N-methyl-D-aspartate receptor(NMDAR) subunits, and ultimately enhancing the expression of synaptic-related proteins PSD95, SYN1, and BDNF in the hippocampus.
Rats ; Animals ; Depression/drug therapy* ; Brain-Derived Neurotrophic Factor ; Neuroprotective Agents ; Tumor Necrosis Factor-alpha/metabolism* ; Neuroinflammatory Diseases ; Diabetes Mellitus ; Receptors, Glutamate ; CX3C Chemokine Receptor 1/genetics*

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.
Animals ; Annexin A1/metabolism* ; CX3C Chemokine Receptor 1/metabolism* ; Chemokine CX3CL1 ; Cognition ; Dendritic Spines/metabolism* ; Ischemic Attack, Transient ; Mice ; Microglia/metabolism*

Patients with diabetic peripheral neuropathy experience debilitating pain that significantly affects their quality of life (Abbott et al., 2011), by causing sleeping disorders, anxiety, and depression (Dermanovic Dobrota et al., 2014). The primary clinical manifestation of painful diabetic neuropathy (PDN) is mechanical hypersensitivity, also known as mechanical allodynia (MA) (Callaghan et al., 2012). MA's underlying mechanism remains poorly understood, and so far, based on symptomatic treatment, it has no effective therapy (Moore et al., 2014).
Animals ; CX3C Chemokine Receptor 1/physiology* ; Chemokine CX3CL1/physiology* ; Diabetes Mellitus, Experimental/complications* ; Diabetes Mellitus, Type 1/complications* ; Diabetic Neuropathies/etiology* ; Hyperalgesia/etiology* ; Mice ; Mice, Inbred C57BL ; Spinal Cord/physiology* ; Streptozocin/pharmacology*

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.
Animals ; Antibodies ; therapeutic use ; Antioxidants ; therapeutic use ; CX3C Chemokine Receptor 1 ; immunology ; metabolism ; Cytokines ; metabolism ; Disease Models, Animal ; Enzyme Inhibitors ; therapeutic use ; Ganglia, Spinal ; drug effects ; metabolism ; Hyperalgesia ; etiology ; metabolism ; Nerve Tissue Proteins ; metabolism ; Pain Threshold ; physiology ; Physical Stimulation ; adverse effects ; Proline ; analogs & derivatives ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; physiology ; Signal Transduction ; physiology ; Spinal Cord ; drug effects ; metabolism ; Thiocarbamates ; therapeutic use ; Up-Regulation ; drug effects ; physiology

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.
Animals ; CD11a Antigen ; metabolism ; CD4-Positive T-Lymphocytes ; metabolism ; CX3C Chemokine Receptor 1 ; Cytokines ; blood ; Diabetes Mellitus, Experimental ; genetics ; therapy ; Enzyme-Linked Immunosorbent Assay ; Histone Code ; Histone Deacetylases ; genetics ; Mice ; Mice, Inbred NOD ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; therapeutic use ; Random Allocation ; Real-Time Polymerase Chain Reaction ; Receptors, CCR5 ; metabolism ; Receptors, Chemokine ; metabolism ; Spleen ; cytology

OBJECTIVETo 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.

METHODSOne 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.

RESULTSCompared 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).

CONCLUSIONOur 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.

Animals ; Blotting, Western ; CX3C Chemokine Receptor 1 ; Curcumin ; pharmacology ; Ganglia, Spinal ; metabolism ; Lumbar Vertebrae ; NF-kappa B ; metabolism ; Pain Threshold ; drug effects ; Rats ; Rats, Sprague-Dawley ; Receptors, Cytokine ; metabolism ; Receptors, HIV ; metabolism ; Sciatic Nerve ; injuries ; metabolism ; Spinal Cord ; metabolism

OBJECTIVETo 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).

METHODSeventy-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.

RESULTCompared 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.

CONCLUSIONThe 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.

Analgesics ; administration & dosage ; Animals ; CX3C Chemokine Receptor 1 ; Curcumin ; administration & dosage ; Disease Models, Animal ; Down-Regulation ; drug effects ; Ganglia, Spinal ; drug effects ; metabolism ; Injections, Intraperitoneal ; Male ; Neuralgia ; drug therapy ; metabolism ; Posterior Horn Cells ; drug effects ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Chemokine ; drug effects ; metabolism

OBJECTIVETo 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).

METHODSThe 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.

RESULTSThe 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).

CONCLUSIONIncreased expressions of CCR5 and CX3CR1 on PBMCs may be indicators in clinical survey for SLE.

Adolescent ; Adult ; CX3C Chemokine Receptor 1 ; Child ; Female ; Humans ; Leukocytes, Mononuclear ; immunology ; Lupus Erythematosus, Systemic ; etiology ; immunology ; Male ; Middle Aged ; RNA, Messenger ; blood ; Receptors, CCR5 ; genetics ; Receptors, Chemokine ; genetics ; Receptors, Interleukin-10 ; genetics ; Receptors, Interleukin-4 ; genetics

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.
Animals ; Arthritis ; chemically induced ; complications ; CX3C Chemokine Receptor 1 ; Injections, Spinal ; Male ; NF-kappa B ; metabolism ; Pain ; drug therapy ; etiology ; metabolism ; Pain Threshold ; drug effects ; Pyrrolidines ; administration & dosage ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Chemokine ; antagonists & inhibitors ; metabolism ; Spinal Cord ; metabolism ; Thiocarbamates ; administration & dosage

OBJECTIVETo 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.

METHODSThe 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.

RESULTSCX3CR1 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).

CONCLUSIONSimvastatin 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.

Acute Coronary Syndrome ; blood ; drug therapy ; CX3C Chemokine Receptor 1 ; Female ; Gene Expression ; drug effects ; Humans ; Hypolipidemic Agents ; therapeutic use ; Male ; Monocytes ; drug effects ; metabolism ; Receptors, Chemokine ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Simvastatin ; therapeutic use