Auditory circuit in the Drosophila brain

Most animals exhibit innate auditory behaviors driven by genetically hardwired neural circuits. In Drosophila, acoustic information is relayed by Johnston organ neurons from the antenna to the antennal mechanosensory and motor center (AMMC) in the brain. Here, by using structural connectivity analysis, we identified five distinct types of auditory projection neurons (PNs) interconnecting the AMMC, inferior ventrolateral protocerebrum (IVLP), and ventrolateral protocerebrum (VLP) regions of the central brain. These auditory PNs are also functionally distinct; AMMC-B1a, AMMC-B1b, and AMMC-A2 neurons differ in their responses to sound (i.e., they are narrowly tuned or broadly tuned); one type of audioresponsive IVLP commissural PN connecting the two hemispheres is GABAergic; and one type of IVLP-VLP PN acts as a generalist responding to all tested audio frequencies. Our findings delineate an auditory processing pathway involving AMMC→IVLP→VLP in the Drosophila brain.     

Insulin stimulates IGFBP-2 expression in 3T3-L1 adipocytes through the PI3K/mTOR pathway

Insulin-like growth factor binding protein 2 (IGFBP-2) has been implicated in the etiology of several diseases, including the metabolic syndrome. Although IGFBP-2 derives mostly from the liver, recent evidence in mice and humans indicate that aging and obesity are associated with altered IGFBP-2 levels in white adipocytes. The present study was aimed at determining the mechanisms that control IGFBP-2 expression in mature adipocytes. IGFBP-2 mRNA and protein expression in serum-deprived 3T3-L1 adipocytes were twofold increased by acute insulin treatment. Co-treatments with the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin or the mammalian target of rapamycin (mTOR) inhibitor rapamycin blunted the effects of insulin. Coherently, IGFBP-2 mRNA levels were robustly increased in adipocytes lacking either TSC2 or 4E-BP1. Insulin triggered the recruitment of CAAT/enhancer binding protein α (C/EBPα) to the IGFBP-2 proximal promoter. These findings suggest that insulin upregulates IGFBP-2 expression through a PI3K/mTOR/C/EBPα pathway in white adipocytes.     

Heparan sulfate mimetics can efficiently mobilize long-term hematopoietic stem cells

Background

Although mobilization of hematopoietic stem cells and hematopoietic progenitor cells can be achieved with a combination of granulocyte colony-stimulating factor and plerixafor (AMD3100), improving approaches for hematopoietic progenitor cell mobilization is clinically important.

Design and Methods

Heparan sulfate proteoglycans are ubiquitous macromolecules associated with the extracellular matrix that regulates biology of hematopoietic stem cells. We studied the effects of a new family of synthetic oligosaccharides mimicking heparan sulfate on hematopoietic stem cell mobilization. These oligosaccharides were administered intravenously alone or in combination with granulocyte colony-stimulating factor and/or AMD3100 in mice. Mobilized hematopoietic cells were counted and phenotyped at different times and the ability of mobilized hematopoietic stem cells to reconstitute long-term hematopoiesis was determined by competitive transplantation into syngenic lethally irradiated mice followed by secondary transplantation.

Results

Mimetics of heparan sulfate induced rapid mobilization of B-lymphocytes, T-lymphocytes, hematopoietic stem cells and hematopoietic progenitor cells. They increased the mobilization of hematopoietic stem cells and hematopoietic progenitor cells more than 3-fold when added to the granulocyte colony-stimulating factor/AMD3100 association. Hematopoietic stem cells mobilized by mimetics of heparan sulfate or by the granulocyte colony-stimulating factor/AMD3100/mimetics association were as effective as hematopoietic stem cells mobilized by the granulocyte colony-stimulating factor/AMD3100 association for primary and secondary hematopoietic reconstitution of lethally irradiated mice.

Conclusions

This new family of mobilizing agents could alone or in combination with granulocyte colony-stimulating factor and/or AMD3100 mobilize a high number of hematopoietic stem cells that were able to maintain long-term hematopoiesis. These results strengthen the role of heparan sulfates in the retention of hematopoietic stem cells in bone marrow and support the use of small glyco-drugs based on heparan sulfate in combination with granulocyte colony-stimulating factor and AMD3100 to improve high stem cell mobilization, particularly in a prospect of use in human therapeutics.     

Urban legends series: oral manifestations of HIV infection

Human immunodeficiency virus‐related oral lesions (HIV‐OLs), such as oral candidiasis (OC) and oral hairy leukoplakia (OHL), have been recognized as indicators of immune suppression since the beginning of the global HIV epidemic. The diagnosis and management of HIV disease and spectrum of opportunistic infection has changed over the past 30 years as our understanding of the infection has evolved. We investigated the following controversial topics: (i) Are oral manifestations of HIV still relevant after the introduction of highly active antiretroviral therapy (HAART)? (ii) Can we nowadays still diagnose HIV infection through oral lesions? (iii) Is the actual classification of oral manifestations of HIV adequate or does it need to be reviewed and updated? (iv) Is there any novelty in the treatment of oral manifestations of HIV infection? Results from extensive literature review suggested the following: (i) While HAART has resulted in significant reductions in HIV‐OLs, many are still seen in patients with HIV infection, with OC remaining the most common lesion. While the relationship between oral warts and the immune reconstitution inflammatory syndrome is less clear, the malignant potential of oral human papillomavirus infection is gaining increasing attention. (ii) Effective antiretroviral therapy has transformed HIV from a fatal illness to a chronic manageable condition and as a result expanded screening policies for HIV are being advocated both in developed and in developing countries. Affordable, reliable, and easy‐to‐use diagnostic techniques have been recently introduced likely restricting the importance of HIV‐OLs in diagnosis. (iii) The 1993 EC‐Clearinghouse classification of HIV‐OLs is still globally used despite controversy on the relevance of periodontal diseases today. HIV‐OL case definitions were updated in 2009 to facilitate the accuracy of HIV‐OL diagnoses by non‐dental healthcare workers in large‐scale epidemiologic studies and clinical trials. (iv) Research over the last 6 years on novel modalities for the treatment of HIV‐OLs has been reported for OC and OHL.     

Previous immunosuppressive therapy is a risk factor for immune reconstitution inflammatory syndrome in Whipple's disease

Introduction

Whipple's disease is a rare chronic infection caused by Tropheryma whipplei. Although most patients respond to antibiotics, in some of them the start of the treatment is followed by recurrence of inflammation. Since polymerase chain reaction is negative for Tropheryma whipplei, this reinflammation cannot be a relapse of Whipple's disease itself. Very recently, it has been recognised as a complication of Whipple's disease and defined immune reconstitution inflammatory syndrome (IRIS). Our aim is to study the prevalence and the clinical features of IRIS in Italian patients with Whipple's disease.

Methods

Evidence of IRIS was retrospectively revaluated in the clinical notes of 22 patients with Whipple's disease. Patients with no evidence of IRIS served as controls for the clinical findings.

Results

Recurrence of arthralgia and/or fever allowed a diagnosis of IRIS in 5/22 patients. One patient died. Previous immunosuppressive therapy was found in all patients with IRIS but only in 7/17 controls (Fisher test, p = 0.039). Age at diagnosis and diagnostic delay were higher in patients with IRIS compared to controls. However, statistical significance was not reached.

Conclusions

IRIS is a frequent complication of Whipple's disease and it can be fatal. The risk of IRIS is greatly increased in patients previously treated with immunosuppressive therapy.     

Clinical and Pathologic Impact of Select Chromatin-modulating Tumor Suppressors in Clear Cell Renal Cell Carcinoma

Background

Historically, VHL was the only frequently mutated gene in clear cell renal cell carcinoma (ccRCC), with conflicting clinical relevance. Recent sequencing efforts have identified several novel frequent mutations of histone modifying and chromatin remodeling genes in ccRCC including PBRM1, SETD2, BAP1, and KDM5C. PBRM1, SETD2, and BAP1 are located in close proximity to VHL within a commonly lost (approximately 90%) 3p locus. To date, the clinical and pathologic significance of mutations in these novel candidate tumor suppressors is unknown.

Objective

To determine the frequency of and render the first clinical and pathologic outcome associated with mutations of these novel candidate tumor suppressors in ccRCC.

Design, setting, and participants

Targeted sequencing was performed in 185 ccRCCs and matched normal tissues from a single institution. Pathologic features, baseline patient characteristics, and follow-up data were recorded.

Outcome measurements and statistical analysis

The linkage between mutations and clinical and pathologic outcomes was interrogated with the Fisher exact test (for stage and Fuhrman nuclear grade) and the permutation log-rank test (for cancer-specific survival [CSS]).

Results and limitations

PBRM1, BAP1, SETD2, and KDM5C are mutated at 29%, 6%, 8%, and 8%, respectively. Tumors with mutations in PBRM1 or any of BAP1, SETD2, or KDM5C (19%) are more likely to present with stage III disease or higher (p = 0.01 and p = 0.001, respectively). Small tumors (<4 cm) with PBRM1 mutations are more likely to exhibit stage III pathologic features (odds ratio: 6.4; p = 0.001). BAP1 mutations tend to occur in Fuhrman grade III–IV tumors (p = 0.052) and are associated with worse CSS (p = 0.01). Clinical outcome data are limited by the number of events.

Conclusions

Most mutations of chromatin modulators discovered in ccRCC are loss of function, associated with advanced stage, grade, and possibly worse CSS. Further studies validating the clinical impact of these novel mutations and future development of therapeutics remedying these tumor suppressors are warranted.     

脐血造血干/祖细胞体外扩增及移植动物模型分析

目的　探讨脐血造血干 /祖细胞体外扩增和体内重建造血的潜能。方法　利用造血干 /祖细胞培养、体外扩增、移植动物模型等技术 ,研究不同比密ficoll分离液分离的脐血造血干 /祖细胞的造血活性。结果　比密 1.0 6 4 g/ml分离液分离的 10 5个脐血MNC中 ,CFU GM集落数为 373± 2 89,BFU E为 12 1± 70。在G3(GM CSF和IL 3融合蛋白 )、IL 6、TPO(thrombopoietin)作用下 ,1.0 6 4 g/ml分离液分离的脐血造血干 /祖细胞在体外扩增 14d ,CFU GM扩增 5 2 .2倍。给经 8.5Gy致死剂量照射的小鼠输注 1.0 6 4 g/ml分离液分离的脐血造血干 /祖细胞 ,体内产生的脾结节 (CFU S)是输注 1.0 77g/ml分离液分离细胞的 2 .2倍。结论　比密 1.0 6 4 g/ml分离液分离的脐血造血干 /祖细胞 ,在体外具有较高的增殖、持续造血的能力及较强的体内造血重建潜能     

Immune reconstitution in human immunodeficiency virus type 1-infected children with different virological responses to anti-retroviral therapy

Immune repopulation, despite virological failure, often occurs in children under highly active anti-retroviral therapy (HAART). The aim of this study was to analyse the characteristics of immune repopulation and activation in children with and without virological response to HAART. Fourteen human immunodeficiency virus type 1 (HIV-1)-infected children with suppression of HIV-1 plasma viraemia (virological responders, VR) and 16 virological non-responders (VNR) to therapy were studied at baseline and after approximately 2 years of HAART. During therapy, CD4+ T cells increased in both groups, but were higher in the VR than in the VNR group. All CD4+ T cell subsets (naive, central memory, effector/memory and CD38+) increased significantly in VR children, while there was a significant increase only in naive cells in VNR children. Naive CD8+ T cells and T cell receptor rearrangement excision circles (TREC), an indicator of thymic output, increased in both VR and VNR children. Activated CD8+ CD38+ T cells decreased in VR but remained high in VNR children. Levels of circulating lipopolysaccharide (LPS), an indicator of microbial translocation, further increased in VNR children. In conclusion, HAART induced an increase in naive cells in all children, regardless of their virological response. However, the persistence of viraemia resulted in an impaired expansion of memory CD4+ T cells susceptible to HIV-1 infection, and together with the microbial translocation sustained the persistence of a high level of immune activation.     

Clonotypic analysis of T cell reconstitution after haematopoietic stem cell transplantation (HSCT) in patients with severe combined immunodeficiency

Haematopoietic stem cell transplantation (HSCT) is performed for treatment of a broad spectrum of illnesses. Reconstitution of an intact immune system is crucial after transplantation to avoid infectious complications, and above all, the establishment of T cell receptor (TCR) diversity is the most important goal in the procedure. Until recently, little has been known of the mechanism of T cell reconstitution in the very early period after HSCT. In this study, we analysed TCR repertoires sequentially in four patients with severe combined immunodeficiency (SCID) before and after HSCT. In all patients, the TCR repertoires were extremely abnormal before HSCT, whereas after transplantation there was progressive improvement in TCR diversity, based on analysis of the TCR Vbeta repertoire and CDR3 size distributions. Somewhat unexpectedly, there was a significant but transient expansion of TCR diversity 1 month after transplantation in all cases. Clonotypic analysis of TCRs performed in one case showed that many T cell clones shared identical CDR3 sequences at 1 month and that the shared fraction decreased progressively. These results indicate that early expansion of TCR diversity may reflect transient expansion of pre-existing mature T cells from the donor blood, independent of de novo T cell maturation through the thymus.