Oestrogen-induced suppression of collagen arthritis; 17 beta-oestradiol is therapeutically active in normal and castrated F1 hybrid mice of both sexes.

The F1 hybrid mouse strain, from B10Q and DBA/1 parentals (the QD strain), is highly susceptible to induction of type II collagen-induced arthritis, an experimental model for rheumatoid arthritis. Males are more susceptible than females. Oophorectomy enhances susceptibility to arthritis and treatment with physiological doses of 17 beta-oestradiol (E2) suppresses disease. E2 treatment lowers the incidence of arthritis also in non-castrated and castrated males, showing that the anti-arthritic effect by oestrogen is not dependent on either sex hormone imprinting effects or interference with male sex hormones. Testosterone treatment of normal females, but not of castrated females, exaggerated development of the disease. In the testosterone-treated normal females, the oestrogen effect on vaginal smear was abolished and ovarian weight decreased, suggesting that the testosterone-mediated enhancing effect is caused by inhibition of ovarian oestrogen production. The crucial importance of oestrogens for the development of arthritis is focused on the effectiveness of treatment with gestation-related doses of E2 of normal, non-castrated females.     

血管紧张素转换酶2基因转染对人内皮细胞MIF表达的影响

目的：探讨重组血管紧张素转换酶2（ACE2）基因转染对体外培养的人血管内皮细胞中由血管紧张素（Ang）II诱导的巨噬细胞移动抑制因子（MIF）表达的影响。方法:克隆和构建含人ACE2基因全长的重组质粒（pACE2），并将之转染入人血管内皮细胞中。分别采用实时定量PCR和Western印迹技术检测转染细胞中的MIF mRNA与蛋白表达情况。结果: Ang Ⅱ（100 nmol/L）和Ang IV（100 nmol/L）刺激后均可诱导人血管内皮细胞中MIF mRNA及蛋白表达增加（P<0.01）。pACE2基因转染可明显抑制内皮细胞中由Ang II和Ang IV诱导的MIF mRNA和蛋白表达（P<0.05）。结论: ACE2基因过表达可明显抑制人内皮细胞中炎症介质MIF的表达，提示ACE2基因具有一定的抗炎症效应。通过调节ACE2基因的活性和表达，很可能为炎症相关疾病如动脉粥样硬化治疗提供新的策略。     

Effects of melanotan II,a melanocortin agonist,on grooming and exploration in rats after repeated restraint/immobilization

2 mg/kg melanotan II (MTII, administered i.p.), a cyclic peptide analog of α-melanocyte stimulating hormone, at a single dose increased grooming in naive rats placed in an unfamiliar open-field device without changing locomotion or rearing. Male rats exposed to restraint/immobilization stress (IS) for 1 h on three consecutive days displayed increased grooming after the second stressor exposure, compared to pre-stress levels. MTII, administered to the rats after IS, enhanced the grooming response compared both to the pre- and post-stress values. The increase was greatest after the first dose and declined over the following two applications. As to the locomotion of rats in the entire experimental space, IS reduced the distance moved only after the first two stressor exposures; MTII did not influence these alterations. Locomotion in the central part of arena was not reduced by the stressor or by MTII, on the contrary, there was an increase in both groups after the third intervention. The only observed change in rearing was an increase in the MTII group after the third restraint exposure. Thus, MTII selectively increased grooming without markedly affecting the spatio-temporal structure of locomotor behavior in the open-field. The decline of MTII enhanced grooming over the three test days may be interpreted in terms of adaptation to the stressor and of the developing tolerance to the peptide.     

Transforming growth factor J3 type II receptor (TGFpRII) mutation in gastric lymphoma without mutator phenotype

A new mutation in the serine-threonine klnase domain of the transforming growth factor β type II receptor (TGFpRII) was found in a case of diffuse, B cell non-Hodgkin's lymphoma of the stomach. A mfssense mutation (ACA to GCA, Thr to Ala) was detected In exon 5, and a wild type allele was also present. This Is the first naturally occurring mutation in the klnase domain of this gene identified in human primary lymphoma. The replication error at three loci was negative, and the poly A tract of exon 3, which is frequently a target of mismatch repair genes, was intact. Malignant lymphoma of B cell origin in the stomach Is an addition to an expanding catalogue of tumors with TGFβRII alterations, and the biological sequelae of the change in the functional domain and the clinical characteristics of the patient in this study are intriguing.     

Charcot-Marie-Tooth disease: molecular characterization of patients from Central and Southern Italy

The syndrome of peroneal muscular atrophy, or Charcot-Marie-Tooth (CMT), disease represents the most common inherited peripheral neuropathy, with a prevalence of about 1 per 2500. The disease is usually transmitted in an autosomal dominant fashion, although it can display all the mendelian patterns of inheritance. The chromosome 17-linked form (CMT1a) appears to be the most common form of the disease in all the ethnic groups studied so far, Italians included, and is due to a tandem duplication in 17p11.2. In order to study the distribution of CMT types and to establish a genotype-phenotype correlation in patients from Central and Southern Italy, we collected 19 CMT pedigrees diagnosed in the years 1992–1993. Simple tandem repeats (STR) polymorphism analysis with the marker RM11-GT and Southern blotting with the probes pVAW409R3 and pVAW412 were performed, demonstrating a high prevalence (about 60%) or 17p duplication in the families studied. No clinical or electrophysiological differences were noted between CMT1 patients with or without 17p duplication, respectively. Two families affected by CMT2 showed no evidence of rearrangement at the D17S122 locus. These data are consistent with the hypothesis of a different molecular basis for CMT2.     

Molecular cloning of a ligand for the inducible T cell gene 4-1BB: a member of an emerging family of cytokines with homology to tumor necrosis factor

4-1BB is an inducible T cell antigen that shows sequence homology to members of an emerging family of cytokine receptors, including those for tumor necrosis factor and nerve growth factor. To aid in the analysis of the function of 4-1BB we have utilized a soluble form of the molecule as a probe to identify and clone the gene which encodes its ligand. The ligand for 4-1BB is a type II membrane glycoprotein that has homology to tumor necrosis factor, lymphotoxin, and the ligands for CD40 and CD27, all of which are themselves ligands to receptors in this superfamily. The gene for 4-IBB is on mouse chromosome 4 and maps close to the p80 form of the tumor necrosis factor receptor as well as the gene for CD30. The gene for 4-IBB ligand maps to mouse chromosome 17, but considerably distal to the tumor necrosis factor and lymphotoxin genes. Interaction of 4-1BB with its ligand induces the proliferation of activated thymocytes and splenic T cells, a response which is mimicked on similar cell populations stimulated with an antibody to 4-1BB.     

Neuroradiology and clinical aspects of Usher syndrome

We describe the neurological evaluation and MRI analysis of 30 patients, belonging to 16 families with Usher syndrome (US) type I and type II (US1 and US2). In addition to the classic visual and audiological abnormalities seen in these patients, we observed abnormal gait in 88.9% of US1 and in 66.7% of US2 patients and abnormal coordination in 33.4% of US1, and in 58.3% of US2. Borderline mental retardation, depression or bipolar affective disorder were observed in 16.7% of US1 and 33.3% of US2 patients. MRI analysis showed cerebellar abnormalities in 50% of US 1 and 75% of US2 patients, but no clear correlation was observed between structural abnormalities and clinical findings. A pattern for the MRI classification of US patients is suggested.     

Human mtDNA hypervariable regions, HVR I and II, hint at deep common maternal founder and subsequent maternal gene flow in Indian population groups

We have analysed the hypervariable regions (HVR I and II) of human mitochondrial DNA (mtDNA) in individuals from Uttar Pradesh (UP), Bihar (BI) and Punjab (PUNJ), belonging to the Indo-European linguistic group, and from South India (SI), that have their linguistic roots in Dravidian language. Our analysis revealed the presence of known and novel mutations in both hypervariable regions in the studied population groups. Median joining network analyses based on mtDNA showed extensive overlap in mtDNA lineages despite the extensive cultural and linguistic diversity. MDS plot analysis based on Fst distances suggested increased maternal genetic proximity for the studied population groups compared with other world populations. Mismatch distribution curves, respective neighbour joining trees and other statistical analyses showed that there were significant expansions. The study revealed an ancient common ancestry for the studied population groups, most probably through common founder female lineage(s), and also indicated that human migrations occurred (maybe across and within the Indian subcontinent) even after the initial phase of female migration to India.     

Action of ANG II and ANP on colon epithelial cells

The interaction of angiotensin II (ANG II) and atrial natriuretic peptide (ANP) on intracellular pH (pH_i) and calcium ([Ca²⁺]_i) was investigated in T84 cells (a permanent cell line derived from human colon epithelium) using the fluorescent stains BCECF/AM and Fluo 4/AM, respectively. pH_i recovery rate mediated by the Na⁺/H⁺ exchanger (NHE) was examined following an NH₄Cl pulse. Under control conditions pH_i recovered at 0.114±0.005 pH units/min (n=35). ANG II (10^–12 or 10^–9 M) increased this value, whilst ANG II (10^–7 M) decreased it. These effects of ANG II were impaired by simultaneous addition of 1 M or 25 M HOE-694, indicating that the stimulatory and inhibitory effects of ANG II on pH_i recovery are mediated in part via the NHE1 and NHE2 isoforms. ANG II increased [Ca²⁺]_i concentration-dependently. ANP (10^–6 M) or dimethyl-BAPTA/AM (50 M) blocked the effects of ANG II on [Ca²⁺]_i and on the rate of pH_i recovery. Thapsigargin (10^–5 M) enhanced the effect of ANG II on [Ca²⁺]_i and reversed its stimulatory effect on the rate of pH_i recovery to an inhibitory one. External Ca²⁺-free solution did not affect the effects of ANG II on these parameters. These data suggest that the [Ca²⁺]_i increase induced by ANG II is dependent on intracellular calcium stores. They are compatible with the demonstration of two sites on the C-terminal of the Na⁺/H⁺ exchanger, one stimulating Na⁺/H⁺ activity by increases of [Ca²⁺]_i in the lower range (at 10^–12 or 10^–9 M ANG II) and the other inhibiting this activity at high [Ca²⁺]_i levels (at 10^–7 M ANG II). ANP or dimethyl-BAPTA/AM, by impairing the pathway mediating the increase in [Ca²⁺]_i, block both the stimulatory and inhibitory effects of ANG II.     

Activation of murine dendritic cells and macrophages induced by Salmonella enterica serovar Typhimurium

Macrophages and dendritic cells (DCs) are antigen-presenting cells (APCs), and the direct involvement of both cell types in the immune response to Salmonella has been identified. In this study we analysed the phenotypic and functional changes that take place in murine macrophages and DCs in response to live and heat-killed Salmonella enterica serovar Typhimurium. Both types of cell secreted proinflammatory cytokines and nitric oxide (NO) in response to live and heat-killed salmonellae. Bacterial stimulation also resulted in up-regulation of costimulatory molecules on macrophages and DCs. The expression of major histocompatibility complex (MHC) class II molecules by macrophages and DCs was differentially regulated by interferon (IFN)-gamma and salmonellae. Live and heat-killed salmonellae as well as lipopolysaccharide (LPS) inhibited the up-regulation of MHC class II expression induced by IFN-gamma on macrophages but not on DCs. Macrophages as well as DCs presented Salmonella-derived antigen to CD4 T cells, although DCs were much more efficient than macrophages at stimulating CD4 T-cell cytokine release. Macrophages are effective in the uptake and killing of bacteria whilst DCs specialize in antigen presentation. This study showed that the viability of salmonellae was not essential for activation of APCs but, unlike live bacteria, prolonged contact with heat-killed bacteria was necessary to obtain maximal expression of the activation markers studied.