Interleukin-10 of red nucleus plays anti-allodynia effect in neuropathic pain rats with spared nerve injury

Our previous studies have shown that pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) in red nucleus (RN) are involved in the development of neuropathic pain and play facilitated roles on the mechanical allodynia induced by peripheral nerve injury. The current study was designed to evaluate the expression and effect of IL-10, an anti-inflammatory cytokine, in the RN of rats with spared nerve injury (SNI). Immunohistochemical staining results demonstrated when 3 weeks after SNI, the expression level of IL-10 in the contralateral RN of SNI rats was apparently higher than those of sham-operated and normal rats. To further study the effect of IL-10 in the development of neuropathic pain, different doses of IL-10 (1.0, 0.5 and 0.1 μg/μl) were microinjected respectively into the RN contralateral to the nerve injury side of SNI rats. Results demonstrated that higher doses of IL-10 (1.0 and 0.5 μg/μl) significantly attenuated the mechanical allodynia of neuropathic rats, while 0.1 μg/μl of IL-10 did not show any analgesic effect. These results suggest that IL-10 of RN participates in the development of neuropathic pain and plays inhibitory roles on the mechanical allodynia induced by SNI.

A point mutation in the DNA-binding domain of HPV-2 E2 protein increases its DNA-binding capacity and reverses its transcriptional regulatory activity on the viral early promoter

Background

The human papillomavirus (HPV) E2 protein is a multifunctional DNA-binding protein. The transcriptional activity of HPV E2 is mediated by binding to its specific binding sites in the upstream regulatory region of the HPV genomes. Previously we reported a HPV-2 variant from a verrucae vulgaris patient with huge extensive clustered cutaneous, which have five point mutations in its E2 ORF, L118S, S235P, Y287H, S293R and A338V. Under the control of HPV-2 LCR, co-expression of the mutated HPV E2 induced an increased activity on the viral early promoter. In the present study, a series of mammalian expression plasmids encoding E2 proteins with one to five amino acid (aa) substitutions for these mutations were constructed and transfected into HeLa, C33A and SiHa cells.

Results

CAT expression assays indicated that the enhanced promoter activity was due to the co-expressions of the E2 constructs containing A338V mutation within the DNA-binding domain. Western blots analysis demonstrated that the transiently transfected E2 expressing plasmids, regardless of prototype or the A338V mutant, were continuously expressed in the cells. To study the effect of E2 mutations on its DNA-binding activity, a serial of recombinant E2 proteins with various lengths were expressed and purified. Electrophoresis mobility shift assays (EMSA) showed that the binding affinity of E2 protein with A338V mutation to both an artificial probe with two E2 binding sites or HPV-2 and HPV-16 promoter-proximal LCR sequences were significantly stronger than that of the HPV-2 prototype E2. Furthermore, co-expression of the construct containing A338V mutant exhibited increased activities on heterologous HPV-16 early promoter P97 than that of prototype E2.

Conclusions

These results suggest that the mutation from Ala to Val at aa 338 is critical for E2 DNA-binding and its transcriptional regulation.

[Construction of multi-epitope DNA vaccine for Toxoplasma gondii and the study on protective immunity response in mice]

AIM

To construct multi-epitope DNA vaccine for Toxoplasma gondii and study its protective immunity response.

METHODS

The gene encoding six polypeptides of T. gondii, which consists of plenty of T and B epitopes, was cloned into the eucaryotic expression vector pcDNA3.1(+). BALB/c mice were vaccinated by this multi-epitope based DNA vaccine (intramuscular needle injection). The specific antibody and T cell proliferation were determined. Meanwhile, the DNA-vaccinated mice were challenged with a lethal dose of T. gondii tachyzoites for further observation.

RESULTS

The eukaryotic expression plasmid (pcDNA3.1/T-ME) encoding plenty of T. gondii epitopes was constructed successfully. pcDNA3.1/T-ME immunization induced T. gondii specific humoral and cellular immunity in mice. The mice immunized with pcDNA3.1/T-ME survived significantly longer than the mice in control after challenged by T. gondii RH strain infection.

CONCLUSION

The multi-epitope DNA vaccine can induce the protective immunity against T. gondii infection effectively in vivo, which is a potential strategy to control T. gondii infection.

[Analgesic effect of interleukin-2 in mouse models of spared nerve injury]

OBJECTIVE

To investigate the analgesic effect of interleukin-2 (IL-2) in mice with spared nerve injury (SNI).

METHOD

IL-2 was intraperitoneally injected in mice with induced SNI, and von Frey Filaments test and cold plate test were carried out to accesses the analgesic effects of IL-2 and the effect of naloxone in antagonizing the effects of IL-2.

RESULTS

IL-2 produced analgesic effects against hyperalgesia and allodynia in mouse models of SNI, and the effect of IL-2 lasted for more than 24 h, showing a double-peak pattern in its action with the two peaks occurring at 30 and 105 min, respectively. The effect of IL-2 could be significantly antagonized by naloxone.

CONCLUSIONS

IL-2 has long-lasting analgesic effects in mouse models of SNI model, showing a double-peak pattern of its action. The analgesic effect of IL-2 is probably mediated by opiate receptor.

Resveratrol induces apoptosis, influences IL-6 and exerts immunomodulatory effect on mouse lymphocytic leukemia both in vitro and in vivo

Resveratrol, a dietary polyphenol found in grapes, has been proposed to act as a chemopreventive or anti-tumor agent in numerous epidemiologic studies. In this study, we investigate the antitumor and immunomodulation effects of resveratrol on mouse lymphocytic leukemia cells L1210 both in vitro and in vivo. Our finding indicates that resveratrol inhibits proliferation, induces apoptosis, and influences cell cycle of L1210 cells in a dose- and time-dependent manner in vitro. Furthermore, resveratrol can exert a dose-related regulatory effect on both innate and specific immune function to L1210-bearing mice. A normalization of CD4/CD8 ratios is noted as well as an enhancement of lymphocyte proliferation, NK cell activity and anti-SRBC titers. Interleukin-6 cellular content and release are suppressed by resveratrol as well as mRNA expression. In conclusion, the data provide new findings with respect to resveratrol mechanism of action to mouse lymphocytic leukemia.

Effective Induction of Type 1 Cytotoxic T Cell Responses in Mice with DNA Vaccine Encoding Two Hepatitis C Virus Cytotoxic T Lymphocyte Epitopes

The aims of this study were to explain whether a multiple cytotoxic T lymphocyte (CTL) epitope-based anti-hepatitis C virus (HCV) DNA vaccine can induce specific CTL responses to each HCV CTL epitope independently and long-term CD8(+) T cell memory responses, and to determine the cytokine secretion pattern and subtype of epitope-specific cytotoxic T cells. A multi-CTL epitope gene, which consists of two epitopes of HCV (H-2(d)-restricted HCV core(133142) and E1(315322)), was cloned into the eukaryotic expression vector pcDNA3.1. BALB/c mice (H-2(d) restricted) were vaccinated intramuscularly with this multi-CTL epitope-based DNA vaccine. The epitope-specific CTLs against target cells (P815,H-2(d) restricted) pulsed with various CTL epitope peptides were detected by lactate dehydrogenase release assay, and the precursor frequency of epitope-specific CTLs was determined by limiting dilution analysis. Cytokines (interleukin [IL]-2, IL-4, and interferon-) in culture supernatants were determined by enzyme-linked immunosorbent assay. The multi-CTL epitope-based DNA vaccine directed against two HCV CTL epitopes could induce specific CTL responses to each of the two CTL epitopes independently and long-term CD8(+) T cell memory responses. The epitope-specific cytotoxic T cells produced helper T cell type 1 cytokines. This work demonstrated that multiepitope DNA vaccination is a potential strategy to control HCV infection.

μ- but not δ- and κ-opioid receptor mediates the nucleus submedius interferon-α-evoked antinociception in the rat

Previous studies have indicated that interferon-alpha (IFN-alpha) can bind to opioid receptors and exerts an antinociceptive effect in both peripheral and central nervous systems. The current study investigated the antinociceptive effect of IFN-alpha unilaterally microinjected into the thalamic nucleus submedius (Sm) of rats on noxious thermal stimulus, and the roles of different subtypes of opioid receptors in mediating the Sm IFN-alpha-evoked antinociception. The results indicated that unilateral microinjection of IFN-alpha (4, 8, 16 pmol) into the Sm dose-dependently increased the hind paw withdrawal latency from the noxious heat stimulus, and this effect was reversed by pretreatment with non-selective opioid receptor antagonist naloxone (200 pmol) and specific mu-opioid receptor antagonist beta-FNA (1 nmol) into the same sites, whereas delta-opioid receptor antagonist ICI174,864 (1 nmol) and kappa-opioid receptor antagonist nor-BNI (1 nmol) failed to alter the effect of IFN-alpha. These results suggest that Sm is involved in IFN-alpha-evoked antinociception and mu- but not delta- and kappa-opioid receptor mediates the Sm IFN-alpha-evoked antinociception.

The roles of different subtypes of opioid receptors in mediating the nucleus submedius opioid-evoked antiallodynia in a neuropathic pain model of rats

Previous studies have indicated that thalamic nucleus submedius is involved in opioid-mediated antinociception in tail flick test and formalin test. The current study examined the effects of opioids microinjected into the thalamic nucleus submedius on the allodynia developed in neuropathic pain model rats, and determined the roles of different subtypes of opioid receptors in the thalamic nucleus submedius opioid-evoked antiallodynia. The allodynic behaviors induced by L5/L6 spinal nerve ligation were assessed by mechanical (von Frey filaments) and cold (4 degrees C plate) stimuli. Morphine (1.0, 2.5, and 5.0 microg) microinjected into the thalamic nucleus submedius contralateral to the nerve injury paw produced a dose-dependent inhibition of the mechanical and cold allodynia, and these effects were reversed by microinjection of the non-selective opioid receptor antagonist naloxone (1.0 microg) into the same site. Microinjection of endomorphin-1 (5.0 microg), a highly selective mu-opioid receptor agonist, and [D-Ala2, D-Leu5]-enkephalin (10 microg), a delta-/mu-opioid receptor agonist, also inhibited the allodynic behaviors, and these effects were blocked by selective mu-opioid receptor antagonist beta-funaltrexamine hydrochloride (3.75 microg). However, the [D-Ala2, D-Leu5]-enkephalin-evoked antiallodynic effects were not influenced by the selective delta-opioid receptor antagonist naltrindole (5.0 microg). Microinjection of the selective kappa-receptor agonist spiradoline mesylate salt (100 microg) into the thalamic nucleus submedius failed to alter the allodynia induced by spinal nerve ligation. These results suggest that the thalamic nucleus submedius is involved in opioid-evoked antiallodynia which is mediated by mu- but not delta- and kappa-opioid receptor in the neuropathic pain model rats.

Molecular studies and prenatal diagnosis of phenylketonuria in Chinese patients

Phenylketonuria (PKU) is one of the most common inborn errors of metabolic disorders. Although PKU induced mental retardation can be prevented after neonatal screening by following treatment with low phenylalanine diet, some parents are seeking prenatal diagnosis. We screened for mutations in exon 3 and 7 of the PAH gene using the DGGE and restriction enzyme method, in combination with STR linkage analysis. Prenatal diagnosis was carried out in 8 PKU families. With this strategy, we are able to make prenatal diagnosis in about 65-70% PKU families. All diagnosis was confirmed in the newborn.

Neonatal screening of phenylketonuria and congenital hypothyroidism in China

Mass screening of newborns for some congenital metabolic diseases is a tremendous achievement in the field of preventive medicine. The pilot study of neonatal screening in China was started in 1981. According to the results of 1.1 million newborn screenings from 8 big cities in the past 6 years, the incidence of phenylketonuria was 1/14,767 and congenital hypothyroidism was 1/5,469. China is a vast country with great economic differences among the different regions, making neonatal screening difficult in some areas. The national neonatal screening coverage rate is only about 2 % at the moment, but in metropolitan centers like Shanghai, the coverage rate reached 95 % in 1997.