Malignant osteopetrosis: bone marrow transplantation

A osteopetrose é uma osteopatia hereditária caracterizada pela deficiência na reabsorção óssea que ocorre por disfunção dos osteoclastos. Com o acúmulo de material osteóide que oblitera o canal medular, ocorre hematopoiese extramedular (hepato-esplenomegalia), obliteração dos forames dos nervos cranianos (cegueira, surdez, paralisias faciais), macrocefalia, protusão da fronte, hipertelorismo, exoftalmo, aumento da pressão intracraniana, retardo na erupção dentária, atraso no crescimento, atraso no desenvolvimento neuropsicomotor, e a morte ocorre precocemente nos primeiros anos de vida. A única alternativa terapêutica curativa é o transplante de medula óssea (TMO) de doador HLA idêntico, pois restabelece a hematopoiese e a função monócito-macrófago, com melhora das lesões ósseas e anormalidades hematopoiéticas, embora não reverta as alterações sensoriais já instaladas. Os autores relatam casos de duas crianças portadoras de osteopetrose maligna submetidas ao transplante de medula óssea com sucesso. A primeira encontra-se no dia +1260 do TMO, com melhora evidente da radiologia esquelética, sem progressão das deficiências neurológicas que apresentava, e com biópsia óssea sem sinais de osteopetrose. O segundo paciente encontra-se no dia + 700, com sinais de reabsorção óssea e sem progressão dos danos neurológicos. Os autores chamam a atenção para a necessidade de diagnóstico precoce da osteopetrose e o rápido encaminhamento para o transplante de medula óssea antes da instalação de seqüelas neurológicas definitivas.Osteopetrosis is an inherited disorder characterized by the inability to reabsorb and remodel bone due to osteoclast dysfunction. The encroachment by bone and mineralized cartilage of the medullary cavities leads to extramedullary hematopoiesis (hepatosplenomegaly) and cranial-nerve foramina leads to blindness, auditory nerve damage, and occulomotor and facial nerve palsies. Defective bone re-absorption also leads to macrocephaly, frontal bossing, hypertelorism, exophthalmos, increased intracranial pressure, retarded tooth eruption, retarded linear growth and psychomotor delay. Death occurs within the first years of life. The only curative therapy is allogeneic bone marrow transplantation with a HLA-identical donor, which restores hematopoiesis, monocyte-macrophage function and bone recovery, but there is no sensorial deficit restoration once present. The authors report two cases of allogeneic bone marrow transplant for infantile malignant osteopetrosis. The first child, on day 1260 after bone marrow transplantation (BMT), showed radiologic bone recovery and no progression of neurological deficits with a bone biopsy showing no signs of osteopetrosis. The second child showed signs of bone re-absorption and no progression of neurological deficits on day 700. The authors emphasize the importance of early diagnosis of osteopetrosis and the necessity of bone marrow transplantation before neurological deficits have begun

AIDS related malignancies in Brazil

There have been relatively few studies of HIV-related malignancies in Brazil. Universal access to antiretroviral drugs in Brazil has changed both the mortality and morbidity rates of AIDS. Nevertheless, there is also extreme poverty in both urban and rural areas and complications of prolonged immune suppression such as mycobacterial and malignant diseases have put a significant strain on the country’s healthcare system. This brief review outlines the existing data regarding AIDS related malignancies in the largest Latin American country

Microenvironment Changes (in pH) Affect VEGF Alternative Splicing

Vascular endothelial growth factor-A (VEGF-A) has several isoforms, which differ in their capacity to bind extracellular matrix proteins and also in their affinity for VEGF receptors. Although the relative contribution of the VEGF isoforms has been studied in tumor angiogenesis, little is known about the mechanisms that regulate the alternative splicing process. Here, we tested microenvironment cues that might regulate VEGF alternative splicing. To test this, we used endometrial cancer cells that produce all VEGF isoforms as a model, and exposed them to varying pH levels, hormones, glucose and CoCl2 (to mimic hypoxia). Low pH had the most consistent effects in inducing variations in VEGF splicing pattern (VEGF121 increased significantly, p < 0.001, when compared to VEGF145, 165 or 189). This was accompanied by activation of the p38 stress pathway and SR proteins (splicing factors) expression and phosphorylation. SF2/ASF, SRp20 and SRp40 down-regulation by siRNA impaired the effects of pH stimulation, blocking the shift in VEGF isoforms production. Taken together, we show for the first time that acidosis (low pH) regulates VEGF-A alternative splicing, may be through p38 activation and suggest the possible SR proteins involved in this process

Prolonged Survival of Allografts Induced by Mycobacterial Hsp70 Is Dependent on CD4+CD25+ Regulatory T Cells

Background: Heat shock proteins (Hsps) are stress induced proteins with immunomodulatory properties. The Hsp70 of Mycobacterium tuberculosis (TBHsp70) has been shown to have an anti-inflammatory role on rodent autoimmune arthritis models, and the protective effects were demonstrated to be dependent on interleukin-10 (IL-10). We have previously observed that TBHsp70 inhibited maturation of dendritic cells (DCs) and induced IL-10 production by these cells, as well as in synovial fluid cells. Methodology/Principal Findings: We investigated if TBHsp70 could inhibit allograft rejection in two murine allograft systems, a transplanted allogeneic melanoma and a regular skin allograft. In both systems, treatment with TBHsp70 significantly inhibited rejection of the graft, and correlated with regulatory T cells (Tregs) recruitment. This effect was not tumor mediated because injection of TBHsp70 in tumor-free mice induced an increase of Tregs in the draining lymph nodes as well as inhibition of proliferation of lymph node T cells and an increase in IL-10 production. Finally, TBHsp70 inhibited skin allograft acute rejection, and depletion of Tregs using a monoclonal antibody completely abolished this effect. Conclusions/Significance: We present the first evidence for an immunosuppressive role for this protein in a graft rejection system, using an innovative approach - immersion of the graft tissue in TBHsp70 solution instead of protein injection. Also, this is the first study that demonstrates dependence on Treg cells for the immunosuppressive role of TBHsp70. This finding is relevant for the elucidation of the immunomodulatory mechanism of TBHsp70. We propose that this protein can be used not only for chronic inflammatory diseases, but is also useful for organ transplantation management.Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Financiadora de Estudos e Projetos (FINEP

Exploring the three PIPs and three TIPs of grapevine for transport of water and atypical substrates through heterologous expression in aqy-null yeast

Aquaporins are membrane channels that facilitate the transport of water and other small molecules across the cellular membranes. We examined the role of six aquaporins of Vitis vinifera (cv. Touriga nacional) in the transport of water and atypical substrates (other than water) in an aqy-null strain of Saccharomyces cerevisiae. Their functional characterization for water transport was performed by stopped-flow fluorescence spectroscopy. The evaluation of permeability coefficients (Pf) and activation energies (Ea) revealed that three aquaporins (VvTnPIP2;1, VvTnTIP1;1 and VvTnTIP2;2) are functional for water transport, while the other three (VvTnPIP1;4, VvTnPIP2;3 and VvTnTIP4;1) are non-functional. TIPs (VvTnTIP1;1 and VvTnTIP2;2) exhibited higher water permeability than VvTnPIP2;1. All functional aquaporins were found to be sensitive to HgCl2, since their water conductivity was reduced (24–38%) by the addition of 0.5 mM HgCl2. Expression of Vitis aquaporins caused different sensitive phenotypes to yeast strains when grown under hyperosmotic stress generated by KCl or sorbitol. Our results also indicate that Vitis aquaporins are putative transporters of other small molecules of physiological importance. Their sequence analyses revealed the presence of signature sequences for transport of ammonia, boron, CO2, H2O2 and urea. The phenotypic growth variations of yeast cells showed that heterologous expression of Vitis aquaporins increased susceptibility to externally applied boron and H2O2, suggesting the contribution of Vitis aquaporins in the transport of these speciesinfo:eu-repo/semantics/publishedVersio

Deletion of Exon 20 of the Familial Dysautonomia Gene Ikbkap in Mice Causes Developmental Delay, Cardiovascular Defects, and Early Embryonic Lethality

Familial Dysautonomia (FD) is an autosomal recessive disorder that affects 1/3,600 live births in the Ashkenazi Jewish population, and leads to death before the age of 40. The disease is characterized by abnormal development and progressive degeneration of the sensory and autonomic nervous system. A single base pair substitution in intron 20 of the Ikbkap gene accounts for 98% of FD cases, and results in the expression of low levels of the full-length mRNA with simultaneous expression of an aberrantly spliced mRNA in which exon 20 is missing. To date, there is no animal model for the disease, and the essential cellular functions of IKAP - the protein encoded by Ikbkap - remain unknown. To better understand the normal function of IKAP and in an effort to generate a mouse model for FD, we have targeted the mouse Ikbkap gene by homologous recombination. We created two distinct alleles that result in either loss of Ikbkap expression, or expression of an mRNA lacking only exon 20. Homozygosity for either mutation leads to developmental delay, cardiovascular and brain malformations, accompanied with early embryonic lethality. Our analyses indicate that IKAP is essential for expression of specific genes involved in cardiac morphogenesis, and that cardiac failure is the likely cause of abnormal vascular development and embryonic lethality. Our results also indicate that deletion of exon 20 abolishes gene function. This implies that the truncated IKAP protein expressed in FD patients does not retain any significant biological function

Silencing microRNA-134 produces neuroprotective and prolonged seizure-suppressive effects

Temporal lobe epilepsy is a common, chronic neurological disorder characterized by recurrent spontaneous seizures. MicroRNAs (miRNAs) are small, noncoding RNAs that regulate post-transcriptional expression of protein-coding mRNAs, which may have key roles in the pathogenesis of neurological disorders. In experimental models of prolonged, injurious seizures (status epilepticus) and in human epilepsy, we found upregulation of miR-134, a brain-specific, activity-regulated miRNA that has been implicated in the control of dendritic spine morphology. Silencing of miR-134 expression in vivo using antagomirs reduced hippocampal CA3 pyramidal neuron dendrite spine density by 21% and rendered mice refractory to seizures and hippocampal injury caused by status epilepticus. Depletion of miR-134 after status epilepticus in mice reduced the later occurrence of spontaneous seizures by over 90% and mitigated the attendant pathological features of temporal lobe epilepsy. Thus, silencing miR-134 exerts prolonged seizure-suppressant and neuroprotective actions; determining whether these are anticonvulsant effects or are truly antiepileptogenic effects requires additional experimentation