Apolipoprotein E controls cerebrovascular integrity via cyclophilin A.

Human apolipoprotein E has three isoforms: APOE2, APOE3 and APOE4. APOE4 is a major genetic risk factor for Alzheimer's disease and is associated with Down's syndrome dementia and poor neurological outcome after traumatic brain injury and haemorrhage. Neurovascular dysfunction is present in normal APOE4 carriers and individuals with APOE4-associated disorders. In mice, lack of Apoe leads to blood-brain barrier (BBB) breakdown, whereas APOE4 increases BBB susceptibility to injury. How APOE genotype affects brain microcirculation remains elusive. Using different APOE transgenic mice, including mice with ablation and/or inhibition of cyclophilin A (CypA), here we show that expression of APOE4 and lack of murine Apoe, but not APOE2 and APOE3, leads to BBB breakdown by activating a proinflammatory CypA-nuclear factor-κB-matrix-metalloproteinase-9 pathway in pericytes. This, in turn, leads to neuronal uptake of multiple blood-derived neurotoxic proteins, and microvascular and cerebral blood flow reductions. We show that the vascular defects in Apoe-deficient and APOE4-expressing mice precede neuronal dysfunction and can initiate neurodegenerative changes. Astrocyte-secreted APOE3, but not APOE4, suppressed the CypA-nuclear factor-κB-matrix-metalloproteinase-9 pathway in pericytes through a lipoprotein receptor. Our data suggest that CypA is a key target for treating APOE4-mediated neurovascular injury and the resulting neuronal dysfunction and degeneration.

U-2940, a human B-cell line derived from a diffuse large cell lymphoma sequential to Hodgkin lymphoma.

Several patterns of association between Hodgkin and non-Hodgkin lymphomas are recognized, some of which support a common cellular origin or shared transformation events for both malignancies. We describe the U-2940 cell line derived from a diffuse large B-cell lymphoma with some features consistent with mediastinal large B-cell lymphoma, clinically apparent 1 month after the initial course of chemotherapy for Hodgkin's disease, fulfilling the criteria for composite malignancies. U-2940 cells display a mature B phenotype with hypermutated IgH rearrangement typical of germinal/postgerminal center origin. The cell line is negative for Epstein-Barr virus and no evidence of t(14;18) was found. U-2940 cells display multiple chromosomal rearrangements similar to recurrent aberrations described in both Hodgkin and non-Hodgkin lymphomas, also partially shared by U-2932 derived from a B-cell lymphoma sequential to Hodgkin's disease. The original large B-cell lymphoma and the U-2940 cell line bear microsatellite instability, an abnormality associated with particular subtypes of non-Hodgkin lymphomas and found in tissues involved by Hodgkin lymphoma. Therefore, U-2940 cells bear several features known to occur in Hodgkin and in non-Hodgkin lymphomas, leading to the assumption that this cell line may constitute a useful tool to address elective pathways of lymphomagenesis and eventually the Hodgkin and non-Hodgkin lymphoma association.

Role of the MEOX2 homeobox gene in neurovascular dysfunction in Alzheimer disease.

Neurovascular dysfunction substantially contributes to Alzheimer disease. Here, we show that transcriptional profiling of human brain endothelial cells (BECs) defines a subset of genes whose expression is age-independent but is considerably altered in Alzheimer disease, including the homeobox gene MEOX2 (also known as GAX), a regulator of vascular differentiation, whose expression is low in Alzheimer disease. By using viral-mediated MEOX2 gene silencing and transfer, we show that restoring expression of the protein it encodes, GAX, in BECs from individuals with Alzheimer disease stimulates angiogenesis, transcriptionally suppresses AFX1 forkhead transcription factor-mediated apoptosis and increases the levels of a major amyloid-beta peptide (Abeta) clearance receptor, the low-density lipoprotein receptor-related protein 1 (LRP), at the blood-brain barrier. In mice, deletion of Meox2 (also known as Gax) results in reductions in brain capillary density and resting cerebral blood flow, loss of the angiogenic response to hypoxia in the brain and an impaired Abeta efflux from brain caused by reduced LRP levels. The link of MEOX2 to neurovascular dysfunction in Alzheimer disease provides new mechanistic and therapeutic insights into this illness.

Neurovascular pathways and Alzheimer amyloid beta-peptide.

According to the prevailing amyloid cascade hypothesis, the onset and progression of a chronic neurodegenerative condition in Alzheimer disease (AD) is initiated by the amyloid beta-peptide (Abeta) accumulation in brain and consequent neuronal toxicity. Recent emphasis on co-morbidity of AD and cerebrovascular disease and the recognition that cerebrovascular dysregulation is an important feature of AD, has shed new light on neurovascular dysfunction as a possible contributor to cognitive decline and Alzheimer neurodegeneration. In the same time, this association has raised a question as to whether there is a causal relationship between cerebrovascular dysregulation and Abeta-initiated pathology, and whether influencing targets in the neurovasculature may prevent different forms of Abeta brain accumulation and/or lower pre-existing accumulates in a later stage of the disease. Pathogenic cascades which operate to dissociate normal transport exchanges between central and peripheral pools of Abeta, and decreased vascular competence leading to brain hypoperfusion and impaired Abeta clearance are discussed. We suggest that there is a link between neurovascular dysfunction and elevated brain Abeta which provides a new scenario for therapeutic interventions to control Alzheimer mental deterioration.

The relative distribution of oncogenic types of human papillomavirus in benign, pre-malignant and malignant cervical biopsies. A study with human papillomavirus deoxyribonucleic acid sequence analysis.

The aim of the present investigation was to define the spectrum of oncogenic types of human papillomavirus (HPV) present in benign, pre-malignant (low-grade and high-grade squamous intraepithelial lesions, LSIL and HSIL) and malignant cervical lesions. The study comprises 215 HPV-positive biopsies, analysed with PCR, followed by sequence analyses of the HPV DNA. Fifeteen oncogenic types of HPV were identified. In 170 benign or pre-maligant alterations, the most common being HPV 16 (51%), HPV 31 (8%), HPV 18 (7%) and HPV 45 (6%). HPV 33, 35, 51, 56, 58, 66, and 70 occurred in about 1-4%. The prevalence of HPV 39, 52, 56, 59 and 73 was <1%. All the observed types of HPV, except 39 and 52, occurred in SIL lesions. The most common oncogenic HPV types (16 and 18), occurring in 45 invasive squamous carcinomas, comprised 76 per cent of the tumours, whereas less frequent HPV types (31, 33, 52, 56, 67, 70 and 73) were each found in about 2-4%. Double HPV infections were not observed. In conclusion, a total of 15 different oncogenic HPV types were identified, of which 13 types were present in pre-malignant cervical lesions and 9 in malignant lesions. This information may have some relevance when HPV analyses are considered as an adjunct to the organised screening of cervical cancer and for those working with the development of HPV vaccines for the prevention of cervical cancer.

Adenocarcinoma of the uterine cervix: the presence of human papillomavirus and the method of detection.

BACKGROUND: Effective screening programs have contributed to a decrease in the incidence of cervical squamous cell carcinomas but have had a limited sensitivity in the detection of adenocarcinoma precursor lesions. The aim of our study was to analyze cervical adenocarcinoma in greater detail: symptoms preceding the detection, the method of detection and the prevalence of human papillomavirus (HPV) with respect to age at diagnosis. MATERIAL AND METHODS: Clinical data were abstracted from the medical records of 82 women with pure invasive cervical adenocarcinomas. As diagnostic tools we used polymerase chain reaction (PCR)-based single-strand conformation polymorphism (SSCP) and/or direct DNA sequencing for HPV detection. RESULTS: Age at diagnosis predicting factors were HPV status, positive lymph nodes, histology and stage. HPV-negativity, lymph node metastases, advanced stage and poor differentiation were all associated with a high diagnostic age. In the multivariate analysis only HPV status was shown to have an independent impact on age at diagnosis, while stage showed only borderline significance. Twenty-three percent of the cancers were detected by screening and the remaining were due to different symptoms. Among the women considered, 93% had a normal Papanicolaou (Pap) smear 3 years before diagnosis and 60% within 1 year. There was no significant correlation between smoking, oral contraceptives and HPV-positivity. CONCLUSIONS: The absence of HPV was significantly associated with a high age at diagnosis. Pap screening had a limited effect in detecting adenocarcinoma at an early stage.

Types of human papillomavirus revealed in cervical adenocarcinomas after DNA sequencing.

In a collection of 173 cervical adenocarcinomas, the prevalence of HPV in relation to the age of women and the distribution of the various oncogenic types of HPV were evaluated. The tumour material was analysed by PCR of the HPV L1 gene followed by direct DNA sequencing and/or the polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) technique for the identification and typing of HPV. In 68% (117/173) of the adenocarcinomas, HPV was present. A significant correlation was observed between the prevalence of HPV and age: in women younger than 40 years, HPV was present in 88%, whereas in women 60 years and older, it was found in only 39% (p<0.001). Among the HPV-positive tumours, type 18 predominated (52%) followed by type 16 (35%) and type 45 (7.7%) while other oncogenic types of HPV (31 and 59) were rarely found. HPV 16 was relatively more frequent in older women but this observation was not significant (p=0.06). HPV-typing by PCR and direct DNA sequence analysis is more specific than analysis by PCR-SSCP, especially among the less frequently occurring types of HPV. Our results further show that the prevalence of HPV in women with cervical adenocarcinomas is age-related and that the most frequently occurring types of HPV are 18, followed by 16 and 45. We have concluded that the oncogenic role of HPV in cervical squamous carcinomas and adenocarcinomas is, in some respects, discrepant.

Somatically mutated Ig V(H)3-21 genes characterize a new subset of chronic lymphocytic leukemia.

Recent studies on the immunoglobulin variable heavy chain (IgV(H)) genes have revealed that B-cell chronic lymphocytic leukemia (B-CLL) consists of at least 2 clinical entities with either somatically mutated or unmutated V(H) genes. We have analyzed the V(H) gene mutation status and V(H) gene usage in 119 B-CLL cases and correlated them to overall survival. A novel finding was the preferential use of the V(H)3-21 gene in mutated cases, whereas biased V(H)1-69 gene usage was found in unmutated cases as previously reported. Interestingly, the subset of mutated cases using the V(H)3-21 gene displayed distinctive genotypic/phenotypic characteristics with shorter average length of the complementarity determining region 3 and clonal expression of lambda light chains. In addition, this mutated subset showed significantly shorter survival than other mutated cases and a similar clinical course to unmutated cases. We therefore suggest that B-CLL cases with mutated V(H)3-21 genes may constitute an additional entity of B-CLL.