The cat locus coeruleus

Summary The neuronal cell bodies of the locus coeruleus (LC) and subcoeruleus (SC) of the cat were investigated using Nissl and Golgi preparations, and electron microscopy. On the basis of morphological criteria — size and shape of cell body, branching pattern of dentrites, distribution of cytoplasmic organelles and number of axosomatic synapses — four types of neuronal perikarya were recognized in each region: medium-sized, small-sized and two groups of intermediate-sized neurons. The medium-sized neurons (30–50 m) had an elongated cell body, thick dendrites with a moderate number of branchings, abundant organelles arranged in concentric rings around the nucleus and a moderate number of axosomatic synapses. They were found throughout the LC and SC and most probably correspond to the larger class of catecholaminergic neurons demonstrated by fluorescence histochemistry. The small neurons (10–25 m) were also seen in both LC and SC and are believed to represent non-monoaminergic local interneurons. They displayed sparsely branching dendrites and a thin rim of cytoplasm containing few organelles. In the SC, some of these small cells occurred in closely associated pairs. Ultrastructural analysis of such pairs revealed a close apposition (80–100 Å) of the cell membranes for long distances (up to 10 m) and a narrowing of the intercellular space (30–40 Å) at some discrete points, perhaps indicative of an electrical interaction. The intermediate-sized neurons exhibited some regional morphological differences, but two distinct subgroups could be distinguished. One was characterized by a low number of axosomatic synapses, while the other exhibited a high number of such contacts. It may be assumed that the two subgroups of intermediate-sized neurons comprise catecholaminergic and indolaminergic neurons.This work was presented at Université Claude Bernard-Lyon as part of a Thèse de 3° Cycle entitled Etude ultrastructurale du Locus Coeruleus du Chat     

Fibroblast activation protein-α in fibrogenic disorders and cancer: more than a prolyl-specific peptidase?

Introduction: Fibroblast activation protein-α (FAP-α) belongs to the family of prolyl-specific serine proteases. FAP-α displays both exopeptidase and endopeptidase/gelatinase/collagenase activities. FAP-α protein and/or activity have been associated with fibrosis, inflammation and cancer, but the protein is undetectable in most normal tissues. FAP-α is selectively expressed at sites of tissue remodeling and repair and enhances tumor progression, suggesting that this protease may be a therapeutic target to treat human disorders associated with fibrotic dysregulation.

Areas covered: In this review, we summarize the mechanisms driving tissue fibrosis and describe some of the enzymes involved in fibrosis, concentrating on FAP-α. We describe its enzymatic properties, discuss the tools developed to control its activity and the problem of selectivity toward the other proteases of the family and outline its potential biological substrates. We also consider non-enzymatic functions of this protein and suggest that repression of FAP-α expression may represent therapeutic options.

Expert opinion: Questions remain regarding the biological functions of FAP-α, either dependent or independent of its enzyme activity. However, as progress is underway to develop FAP-α-specific inhibitors and therapeutic antibodies, its role in diseases associated with fibrosis is starting to emerge, ultimately leading to novel therapeutic options for inflammatory and oncologic diseases.     

Skeletal survey in advanced multiple myeloma: radiographic versus MR imaging survey

In an attempt to compare the sensitivity of bone radiographs and bone marrow magnetic resonance (MR) imaging for bone lesion detection in patients with stage III multiple myeloma (MM) and to evaluate the possible consequences of the replacement of the conventional radiographic skeletal survey (RSS) by an MR survey of the spinal and pelvic bone marrow in these patients, we obtained MR studies of the thoracic and lumbar spine, pelvis and proximal femurs in addition to the conventional RSS (including radiographs of the skull, entire spine, pelvis, ribs, humerus and femurs) in 80 consecutive patients with newly diagnosed stage III MM according to the Durie and Salmon staging system (based on blood tests and on the RSS). The performance of MR and radiographic studies to detect bone lesions in given anatomic areas and in given patients were compared. The consequences on MM staging following the substitution of the RSS by the MR survey were assessed. MR imaging was superior to radiographs for lesion detection in the spine (76% v 42% of patients) and pelvis (75% v 46% of patients). The RSS was superior to the limited MR imaging survey for the detection of bone involvement in the patient population (87.5% v 79% of patients). If the RSS had been replaced by the MR imaging survey for patient staging, 7/80 patients would have been categorized as stage I and one as stage II MM on the basis of normal MR findings and biological findings consistent with these stages. Substitution of the RSS by a limited spinal and pelvic marrow MR survey would lead to 'understaging' of 10% of patients with otherwise stage III MM on the basis of blood tests and the conventional RSS.     

Genetic,structural and functional properties of an IgG DNA-binding monoclonal antibody from a lupus patient with nephritis

Antibodies binding to double-stranded (ds) DNA are strongly associated with renal involvement in patients with systemic lupus erythematosus (SLE). We have generated two new IgG DNA-binding monoclonal antibodies (mAb), RH-14 and DIL-6, from the peripheral blood lymphocytes of two SLE patients with glomerulonephritis using the heteromyeloma cell line CB-F7. RH-14 is an IgG1 λ antibody which also bound to single-stranded (ss)DNA, histones and nucleosomes. DIL-6 is an IgG3 λ antibody with restricted antigen binding specificity. cDNA encoding the variable regions of the heavy (V_H) and light (V_L) chains of RH-14 was sequenced and the antigen binding site of this mAb was computer modelled. Sequence analysis of V_H and V_L regions of RH-14 showed that V_H is derived from germ-line gene V3-7, a member of the V_H3 family, and V_L is derived from DPL 11, a member of the V_λ2 family. Somatic mutations and basic amino acid residues are identified in the complementarity- determining regions of both V_H and V_L regions. The nephritogenic properties of these mAb were analyzed by implanting and growing the hybridoma cells secreting the mAb in the peri toneum of SCID mice. The animals that received the RH-14 hybridoma produced higher levels of proteinuria (3 to ≥ 4) (p < 0.001) compared to the groups that received DIL-6 (trace to ≥ 1) or CB-F7 (trace). Electron microscopy of kidney sections from all the RH-14- implanted animals showed granular immunoglobulin deposition in the renal glomerular capil laries and mesangium. In this study we have shown for the first time using electron micros copy that a human IgG anti-dsDNA mAb, RH-14, is nephritogenic and that deposition of such an antibody alone is sufficient to induce renal damage.     

Philadelphia-like translocation t(9;22)(q34;q11) found in a follicular lymphoma involving not BCR and ABL but IGL-mediated rearrangement of an unknown gene on 9q34

In a case of follicular center cell lymphoma (FCCL) without evidence of histologic progression towards a high-grade lymphoma, t(9;22)(q34;q11) was found simultaneously with a t(14;18)(q32;q21) and a t(8;14)(q24;q32). Molecular studies of this case showed BCL2 and MYC rearrangements in addition to the rearrangements of immunoglobulin heavy (IGH) and lambda (IGL) loci. Investigation of the t(9;22) using Southern blot and RT-PCR analysis failed to detect M-bcr or m-bcr rearrangements of BCR. Two-color fluorescence in situ hybridization (FISH) with ABL and BCR probes revealed presence of a “fusion” signal, but its atypical localization [der(9)] and gene order [cen-ABL-BCR-tel] indicated that this translocation differed from the t(9;22) in chronic myeloid leukemia and did not involve either ABL or BCR. In addition, further FISH analysis using 9q34- and 22q11-specific probes localized the breakpoint on chromosome 9 distal to the NOTCH1 gene and the breakpoint on 22q11 in the IGL gene cluster. These results indicate an IGL-mediated rearrangement of an unknown gene at 9q34 that together with BCL2 and MYC might be involved in the lymphomagenesis of the present case of FCCL and perhaps in other cases of non-Hodgkin lymphoma in which t(9;22) is sporadically occurring. Genes Chromosomes Cancer 20:113–119, 1997. © 1997 Wiley-Liss, Inc.     

Cytotoxic effects of combination of oxidosqualene cyclase inhibitors with atorvastatin in human cancer cells

Ten oxidosqualene cyclase inhibitors with high efficacy as cholesterol-lowering agents and of different chemical structure classes were evaluated as potential anticancer agents against human cancer cells from various tissue origins and nontumoral human-brain-derived endothelial cells. Inhibition of cancer cell growth was demonstrated at micromolar concentrations, comparable to the concentrations of statins necessary for antitumor effect. Human glioblastoma cells were among the most sensitive cells. These compounds were also able to decrease the proliferation of angiogenic brain-derived endothelial cells, as a model of tumor-induced neovasculation. Additive effects in human glioblastoma cells were also demonstrated for oxidosqualene cyclase inhibitors in combination with atorvastatin while maintaining selectivity against endothelial cells. Thus, not only statins targeting the 3-hydroxy-3-methylglutaryl coenzyme A reductase but also inhibitors of oxidosqualene cyclase decrease tumor growth, suggesting new therapeutic opportunities of combined anti-cholesterol agents for dual treatment of glioblastoma.     

Present status and perspectives in functional analysis of p53 in chronic lymphocytic leukemia

Aberrations of TP53 (mutations and/or deletions) are associated with a dismal prognosis in chronic lymphocytic leukemia (CLL). Complete loss of ATM is another mechanism of failed DNA damage response and also associated with poorer prognosis in CLL. However, p53 dysfunction may arise through alternative mechanisms unrelated to structural aberrations (deletion and/or mutation) of TP53 or ATM, and thus be undetectable by traditional DNA-directed approaches (fluorescence in situ hybridization [FISH], sequencing, karyotyping). In order to address the latter changes, and also to better understand the consequences of TP53/ATM aberrations, p53 functional assays have recently been developed. The purpose of dynamic assessment of p53 response in CLL is to carry out a comprehensive analysis of all mechanisms causing p53-deficient phenotype, including those unrelated to genomic aberrations of TP53 and ATM. The present review focuses on the current knowledge of p53 function assays in CLL, including important features such as technical issues, correlation with structural aberrations and clinical value.     

Cigarette smoking, body mass index, and stressful life events as risk factors for psoriasis: results from an Italian case-control study

We conducted a case-control study to analyse the association of psoriasis of recent onset with smoking habits, body mass index (BMI) and stressful life events. Cases (n=560; median age 38) were patients with a first diagnosis of psoriasis and a history of skin manifestations of no longer than two years after the reported disease onset. Patients with a new diagnosis of skin diseases other than psoriasis (n=690; median age 36) were selected as controls. The risk of psoriasis was higher in ex- and current smokers than in never-smokers, the relative risk estimates (OR) being 1.9 for ex-smokers and 1.7 for smokers. Smoking was strongly associated with pustular lesions (32 patients, OR=5.3 for smokers). The frequency of psoriasis varied significantly in relation to a family history of psoriasis in first degree relatives, BMI (OR=1.6 and 1.9 for over weighted, BMI 26-29, and obese, BMI >/= 30, respectively) and stressful life event score (compared to the lower index quartile, the OR being 2.2 for index values >/=115). Risk estimates, when taking into consideration the combined effect of these factors with smoking habits, were consistent with a multiplicative model of risk combination with no significant statistical interaction.