RESUMO
N-acetylgalactosamine 4-sulfate 6-O-sulfotransferase (GalNAc4S-6ST) is a sulfotransferase responsible for biosynthesis of chondroitin sulfate E (CS-E). CS-E plays important roles in numerous biological events, such as neurite outgrowth. However, the role of GalNAc4S-6ST in tumor progression remains unknown. In the present study, we analyzed expression of GalNAc4S-6ST mRNA in colorectal cancer by combining real-time RT-PCR with in situ hybridization (ISH) using archived formalin-fixed and paraffin-embedded tissue sections. In 57.5% of 40 patients, expression of GalNAc4S-6ST mRNA was increased in cancer tissues compared with paired normal mucosa. ISH using an RNA probe specific for GalNAc4S-6ST revealed that it was expressed in colorectal cancer cells. Analysis of the relationship between expression of GalNAc4S-6ST as determined by real-time RT-PCR assay and various clinicopathological variables revealed that GalNAc4S-6ST was associated with vessel invasion, although a statistically significant difference was not seen (P=0.125 for lymphatic vessel invasion and P=0.242 for venous invasion). Taken together, we show that real-time RT-PCR combined with ISH is useful to investigate quantitatively GalNAc4S-6ST mRNA expression in formalin-fixed and paraffin-embedded tissue sections, and that GalNAc4S-6ST expressed by colorectal cancer cells plays a minor role in tumor progression.
RESUMO
Transient receptor potential vanilloid (TRPV)1 is a ligand-gated cation channel expressed by primary sensory neurons, including those in the dorsal root ganglia (DRG). TRPV1 plays an essential role in development of inflammatory thermal hyperalgesia after tissue injury and its expression in rat lumbar DRG is increased after hindpaw inflammation. However, the identity of factors mediating forepaw inflammatory hyperalgesia has remained elusive. Here, we examined behavioral responses to noxious thermal stimuli after forepaw inflammation in rats and found that inflammation induced by intraplantar injection of complete Freund's adjuvant significantly reduced hot-plate latency (HPL) at 50 degrees C. TRPV1 expression levels in the ipsilateral cervical DRG were also elevated after forepaw inflammation. By contrast, HPL at 56 degrees C was not shortened after forepaw inflammation and expression of TRPV2, a TRPV1 homolog, in the DRG was not increased. Paratracheal injection of short interfering RNA targeting TRPV1 blocked TRPV1 up-regulation in cervical DRG and abolished inflammation-mediated HPL reductions seen at 50 degrees C. However, thermal hyperalgesia previously established by inflammation was not reversed by short interfering RNA injection. These results indicate that: (i) enhanced TRPV1 expression in cervical DRG is closely associated with development of inflammatory thermal hyperalgesia in the forepaw after tissue injury and (ii) RNA interference targeting TRPV1 prevents inflammatory thermal hyperalgesia after forepaw injuries but does not ameliorate it when already established in a rat model of nociceptive pain representing upper limb injury in humans.
Assuntos
Hiperalgesia/genética , Inflamação/genética , Neurônios Aferentes/metabolismo , Nociceptores/fisiopatologia , Interferência de RNA , Canais de Cátion TRPV/genética , Animais , Modelos Animais de Doenças , Regulação para Baixo/genética , Membro Anterior/inervação , Membro Anterior/fisiopatologia , Adjuvante de Freund/efeitos adversos , Gânglios Espinais/metabolismo , Gânglios Espinais/fisiopatologia , Hiperalgesia/metabolismo , Hiperalgesia/fisiopatologia , Inflamação/metabolismo , Inflamação/fisiopatologia , Mediadores da Inflamação/efeitos adversos , Masculino , Nociceptores/metabolismo , Células PC12 , Limiar da Dor/fisiologia , RNA Interferente Pequeno/farmacologia , Ratos , Ratos Sprague-Dawley , Tempo de Reação/genética , Células Receptoras Sensoriais/metabolismo , Células Receptoras Sensoriais/fisiopatologia , Pele/inervação , Pele/fisiopatologiaRESUMO
Helicobacter pylori infects the stomachs of nearly a half the human population, yet most infected individuals remain asymptomatic, which suggests that there is a host defense against this bacterium. Because H. pylori is rarely found in deeper portions of the gastric mucosa, where O-glycans are expressed that have terminal alpha1,4-linked N-acetylglucosamine, we tested whether these O-glycans might affect H. pylori growth. Here, we report that these O-glycans have antimicrobial activity against H. pylori, inhibiting its biosynthesis of cholesteryl-alpha-D-glucopyranoside, a major cell wall component. Thus, the unique O-glycans in gastric mucin appeared to function as a natural antibiotic, protecting the host from H. pylori infection.