Cysteine proteinase inhibitors regulate human and mouse osteoclastogenesis by interfering with RANK signaling

The cysteine proteinase inhibitor cystatin C inhibited RANKL-stimulated osteoclast formation in mouse bone marrow macrophage cultures, an effect associated with decreased mRNA expression of Acp5, Calcr, Ctsk, Mmp9, Itgb3, and Atp6i, without effect on proliferation or apoptosis. The effects were concentration dependent with half-maximal inhibition at 0.3 μM. Cystatin C also inhibited osteoclast formation when RANKL-stimulated osteoclasts were cultured on bone, leading to decreased formation of resorption pits. RANKL-stimulated cells retained characteristics of phagocytotic macrophages when cotreated with cystatin C. Three other cysteine proteinase inhibitors, cystatin D, Z-RLVG-CHN2 (IC50 0.1 μM), and E-64 (IC 50 3 μM), also inhibited osteoclast formation in RANKL-stimulated macrophages. In addition, cystatin C, Z-RLVG-CHN2, and E-64 inhibited osteoclastic differentiation of RANKL-stimulated CD14+ human monocytes. The effect by cystatin C on differentiation of bone marrow macrophages was exerted at an early stage after RANKL stimulation and was associated with early (4 h) inhibition of c-Fos expression and decreased protein and nuclear translocation of c-Fos. Subsequently, p52, p65, IκBα, and Nfatc1 mRNA were decreased. Cystatin C was internalized in osteoclast progenitors, a process requiring RANKL stimulation. These data show that cystatin C inhibits osteoclast differentiation and formation by interfering intracellularly with signaling pathways downstream RANK. © FASEB.

Investigação sorológica de espécies de Ehrlichia em cães, equinos e humanos de um assentamento rural do sul do Brasil

The aims of this study were to determine the seroprevalence of Ehrlichia spp. and risk factors for exposure in a restricted population of dogs, horses, and humans highly exposed to tick bites in a Brazilian rural settlement using a commercial ELISA rapid test and two indirect immunofluorescent assays (IFA) with E. canis and E. chaffeensis crude antigens. Serum samples from 132 dogs, 16 horses and 100 humans were used. Fifty-six out of 132 (42.4%) dogs were seropositive for E. canis. Dogs > one year were more likely to be seropositive for E. canis than dogs ≤ one year (p = 0.0051). Ten/16 (62.5%) and 8/16 (50%) horses were seropositive by the commercial ELISA and IFA, respectively. Five out of 100 (5%) humans were seropositive for E. canis and E. chaffeensis. Rhipicephalus sanguineus (n = 291, 97.98%) on dogs and Amblyomma cajennense (n = 25, 96.15%) on horses were the most common ticks found. In conclusion, anti-Ehrlichia spp. antibodies were found in horses; however, the lack of a molecular characterization precludes any conclusion regarding the agent involved. Additionally, the higher seroprevalence of E. canis in dogs and the evidence of anti-Ehrlichia spp. antibodies in humans suggest that human cases of ehrlichiosis in Brazil might be caused by E. canis, or other closely related species.

Bovine herpesvirus type 5 infection regulates Bax/BCL-2 ratio

Bovine herpesvirus 5 (BoHV-5) is an α-herpesvirus that causes neurological disease in young cattle and is also occasionally involved in reproductive disorders. Although there have been many studies of the apoptotic pathways induced by viruses belonging to the family Herpesviridae, there is little information about the intrinsic programmed cell death pathway in host-BoHV-5 interactions. We found that BoHV-5 is able to replicate in both mesenchymal and epithelial cell lines, provoking cytopathology that is characterized by cellular swelling and cell fusion. Viral antigens were detected in infected cells by immunofluorescence assay at 48 to 96 h post-infection (p.i.). At 48 to 72 h p.i., anti-apoptotic BCL-2 antigens were found at higher levels than Bax antigens; the latter is considered a pro-apoptotic protein. Infected cells had increased BCL-2 phenotype cells from 48 to 96 h p.i., based on flow cytometric analysis. At 48 to 96 h p.i., Bax mRNA was not expressed in any of the infected cell monolayers. In contrast, BCL-2 mRNA was found at high levels at all p.i. in both types of cells. BoHV-5 replication apparently modulates BCL-2 expression and gene transcription, enhancing production of virus progeny. © FUNPEC-RP.

Proteção de bovinos contra Haemonchus placei e Haemonchus contortus após imunização com antígenos oriundos da membrana intestinal de H. contortus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito de micobactéria ambiental (Mycobacterium avium) na imunidade induzida pela vacina gênica para tuberculose (pVAXhsp65)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da carga viral do virus da hepatite C em diferentes compartimentos biológicos: influência na predição da recidiva virológica

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Caracterização e validação de anticorpo monoclonal murino anti-Linfócitos B humanos para uso em citometria de fluxo e imunoquímica

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB