Wnt1/ß-catenin signaling upregulates spinal VGLUT2 expression to control neuropathic pain in mice.

Vesicular glutamate transporter 2 (VGLUT2)-which uptakes glutamate into presynaptic vesicles-is a fundamental component of the glutamate neurotransmitter system. Although several lines of evidence from genetically modified mice suggest a possible association of VGLUT2 with neuropathic pain, the specific role of VGLUT2 in the spinal cord during neuropathic pain, and its regulatory mechanism remain elusive. In this study, we report that spared nerve injury induced an upregulation of VGLUT2 in the spinal cord, and intrathecal administration of small hairpin RNAs (shRNA) against VGLUT2 before or after surgery attenuated mechanical allodynia, and pathologically-enhanced glutamate release. Meanwhile, nerve injury activated the Wnt1/ß-catenin signaling pathway in a quick-onset and sustained manner, and blocking the Wnt1 signaling with a Wnt1 targeting antibody attenuated neuropathic pain. In naïve mice, administration of a Wnt agonist or Wnt1 increased spinal VGLUT2 protein levels. Moreover, intrathecal administration of the Wnt/ß-catenin inhibitor, XAV939 attenuated mechanical allodynia, and this effect was concurrent with that of VGLUT2 downregulation. Pretreatment with VGLUT2 shRNAs abolished the allodynia induced by the Wnt agonist or Wnt1. These findings reveal a novel mechanism wherein there is Wnt1/ß-catenin-dependent VGLUT2 upregulation in neuropathic pain, thus potentiating the development of new therapeutic strategies in pain management.

Selective downregulation of vesicular glutamate transporter2 in ventral posterolateral nucleus of thalamus attenuates neuropathic mechanical allodynia in mice.

Vesicular glutamate transporters (VGLUTs) transport glutamate into synaptic vesicles prior to exocytotic release. The expression pattern of VGLUT2 and studies of genetically modified mice have revealed that VGLUT2 contributes to neuropathic pain. We previously showed that VGLUT2 is upregulated in supraspinal regions including the thalamus in mice following spared nerve injury (SNI), and blocking VGLUTs using the VGLUT inhibitor CSB6B attenuated mechanical allodynia. To further evaluate the role of VGLUT2 in neuropathic pain, in this study, we developed a lentiviral vector expressing small hairpin RNAs (shRNAs) against mouse VGLUT2, which was injected into the ventral posterolateral (VPL) nucleus of the thalamus in the presence or absence of SNI. The administration of VGLUT2 shRNAs result in downregulation of VGLUT2 mRNA and protein expression, and decreased extracellular glutamate release in primary cultured neurons. We also showed that VGLUT2 shRNAs attenuated SNI-induced mechanical allodynia, in accordance with knockdown of VGLUT2 in the VPL nucleus in mice. Accordingly, our study supports the essential role of supraspinal VGLUT2 in neuropathic pain in adult mice and, thereby, validates VGLUT2 as a potential target for neuropathic pain therapy.

Effects of storage time on Cytomegalovirus DNA stability in plasma determined by quantitative real-time PCR.

Quantitative real-time PCR (QRT-PCR) assays are faster, more precise, and more sensitive quantitative laboratory methods for monitoring serial CMV DNA viral load in patients undergoing organ or hematopoietic stem cell transplantation. Clinical laboratories often face practical concerns about the storage of specimens from these patients to ensure the accuracy and reproducibility of CMV viral load test results. Different studies that have assessed CMV DNA stability have shown mixed results. Therefore, we analyzed CMV DNA stability of 30 EDTA plasma samples in samples containing between 300 and 100,000copies/ml over a 21 day period. The concentration of CMV DNA in all samples stored at 4°C for 21 days did not differ significantly from the baseline viral load (t=0.242, p=0.810), and no trend was evident to indicate continued degradation over a 2 week period.

Association between PAI-1 4G/5G Polymorphisms and osteonecrosis of femoral head: a meta-analysis.

BACKGROUND: The polymorphism of the plasminogen activator inhibitor-1 (PAI-1) 4 G/5 G gene has been correlated with susceptibility to osteonecrosis of the femoral head (ONFH), but study results are controversial. The aim of this study was to derive a more precise estimation of the relationship between the PAI-1 4 G/5 G Gene polymorphism and ONFH by performing a meta-analysis. METHODS: The meta-analysis was based on five eligible case-control studies involving 419 cases and 969 controls and summarized data indicating the association between PAI-1 polymorphism and risk of osteonecrosis of the femoral head. Odds ratios (OR) with 95% confidence intervals (95% CI) were used to assess the strength of this association in the random-effects model or fixed-effects model. RESULTS: A significant association between PAI-1 4 G/5 G polymorphism and ONFH susceptibility was observed for 4G4G+4G5G vs. 5G5G (OR=1.766, 95% CI 1.279-2.437, P=0.001), 4 G/4G vs. 4 G/5 G+5G/5 G (OR=2.050, 95% CI 1.581-2.657, P=0.000), 4 G/4G vs. 5 G/5G (OR=2.553, 95% CI 1.345-4.846, P=0.004), and 4 G vs. 5 G (OR=1.758, 95% CI 1.236-2.500, P=0.002). No significant association between PAI-1 4 G/5 G polymorphism and ONFH susceptibility was observed for 4 G/5 G vs. 5 G/5G (OR=1.327, 95% CI 0.939-1.877, P=0.109). CONCLUSIONS: This meta-analysis suggested that 4 G/5 G polymorphism of the PAI-1 gene was a risk factor for ONFH. This study also suggests that the PAI-1 4G4G genotype may indicate a risk for ONFH.

TNF-α-308G/A polymorphisms and nasopharyngeal cancer risk: a meta-analysis.

Previous evidence has indicated that the polymorphism of tumor necrosis factor-alpha (TNF-α) is a risk factor for various cancers, however, the association between TNF-α-308G/A polymorphism and nasopharyngeal carcinoma (NPC) remains controversial and ambiguous. The aim of this study is to clarify the association between TNF-α polymorphism and NPC using meta-analysis. A meta-analysis based on five eligible case-control studies involving 499 cases and 1,470 controls was carried out to summarize the data on the association between TNF-α-308G/A polymorphism and NPC risk. Odds ratios (OR) with 95 % confidence intervals (95 % CI) were used to assess the strength of this association in the fixed-effect model. The pooled analyses showed no significant association between TNF-α-308G/A polymorphism and NPC (AA vs. GG: OR = 1.38, P = 0.193; GA vs. GG: OR = 0.92, P = 0.585; GA + AA vs. GG: OR = 1.00, P = 0.972; AA vs. GA + GG: OR = 1.44, P = 0.138). We also categorized by geographic location (non-Asian or Asian) for subgroup analysis; the results also showed no significant association between TNF-α-308G/A polymorphism and NPC risk in all of the comparisons. No publication bias was observed in this study (t = -0.11, P = 0.918, 95 % CI = -4.893-4.559). No significant association was found between TNF-α-308G/A polymorphism and the risk for NPC.