BBS4 protein has basal body/ciliary localization in sensory organs but extra-ciliary localization in oligodendrocytes during human development.

Bardet-Biedl syndrome protein 4 (BBS4) localization has been studied in human embryos/fetuses from Carnegie stage 15 to 37 gestational weeks in neurosensory organs and brain, underlying the major clinical signs of BBS. We observed a correlation between the differentiation of the neurosensory cells (hair cells, photoreceptors, olfactory neurons) and the presence of a punctate BBS4 immunostaining in their apical cytoplasm. In the brain, BBS4 was localized in oligodendrocytes and myelinated tracts. In individual myelinated fibers, BBS4 immunolabelling was discontinuous, predominantly at the periphery of the myelin sheath. BBS4 immunolabelling was confirmed in postnatal developing white matter tracts in mouse as well as in mouse oligodendrocytes cultures. In neuroblasts/neurons, BBS4 was only present in reelin-expressing Cajal-Retzius cells. Our results show that BBS4, a protein of the BBSome, has both basal body/ciliary localization in neurosensory organs but extra-ciliary localization in oligodendrocytes. The presence of BBS4 in developing oligodendrocytes and myelin described in the present paper might attribute a new role to this protein, requiring further investigation in the field of myelin formation.

GLUT1 expression in human papillomavirus-positive anogenital lesions.

BACKGROUND: GLUT1, an ubiquitous glucose transporter in the mammalian cells, is upregulated in many tumours, including human papillomavirus (HPV)-induced head and neck or cervical cancer. OBJECTIVE: To study in anogenital lesions whether or not GLUT1 expression correlates with genomic high-risk HPV integration, the first step in neoplastic transformation. METHODS: Forty-three HPV-positive biopsies positive for either low-risk or high-risk HPV were selected. Paraffin sections adjacent to those tested for the presence of HPV were processed for GLUT1 immunocytochemistry. GLUT1 expression was analysed by two histologists, blinded to HPV type and status and then compared with HPV typing results. RESULTS: Two main staining patterns were observed, either staining from the basal to the granular layer or staining of superficial layers only. The first staining pattern corresponded to lesions with high number of episomal HPV-positive nuclei. Superficial staining was observed in lesions with low number of episomal HPV nuclei or when high-risk HPV was integrated in the cell genome. CONCLUSION: Our results show that GLUT1 overexpression correlates with the number of episomally infected cells in the lesion, but not with the type (low or high risk) of HPV.

2-Chlorodeoxyadenosine (cladribine) induces apoptosis in human monocyte-derived dendritic cells.

2-Chlorodeoxyadenosine (cladribine, CdA) is an immunosuppressive drug that is licensed to treat hairy cell leukaemia, and has been shown recently to have beneficial effects in patients with multiple sclerosis (MS). The therapeutic effects of CdA have been suggested to be mediated partly through its potent toxicity towards lymphocytes. However, the effects of CdA on other immune cells are poorly understood. In the present study, we investigated the effects of CdA on the induction of apoptosis in human monocytes, monocyte-derived immature (ImDC) and mature (mDC) dendritic cells. Treatment of monocytes with CdA strongly induced apoptosis after 24 h, while apoptosis induction in DC was evident after 72 h. Furthermore, CdA treatment strongly induced caspase-3 and caspase-9 in monocytes, whereas activation of caspases was undetected in DC. The mitochondrial membrane potential in DC was reduced significantly after CdA treatment. DNA hypodiploid assessment showed fragmented nuclei in DC after CdA treatment together with activation of p53 protein. These results revealed that CdA induces caspase-independent apoptosis in DC and suggest cell type specific effects of CdA. This mechanism may contribute to the effect of CdA in autoimmune diseases.