Análise do transcriptoma das glândulas venenosas do escorpião Tityus stigmurus

In Brazil, accidents with scorpions are considered of medical importance, not only by the high incidence, but also for the potentiality of the venom from some species in determining severe clinical conditions. Tityus stigmurus is a widely distributed scorpion species in Northeastern Brazil and known to cause severe human envenomations, inducing pain, hyposthesia, edema, erythema, paresthesia, headaches and vomiting. The present study uses a transcriptomic approach to characterize the molecular repertoire from the non-stimulated venom gland of Tityus stigmurus scorpion. A cDNA library was constructed and 540 clones were sequenced and grouped into 37 clusters, with more than one EST (expressed sequence tag) and 116 singlets. Forty-one percent of ESTs belong to recognized toxin-coding sequences, with antimicrobial toxins (AMP-like) the most abundant transcripts, followed by alfa KTx- like, beta KTx-like, beta NaTx-like and alfa NaTx-like. Our analysis indicated that 34% include other possible venom molecules , whose transcripts correspond to anionic peptides, hypothetical secreted peptides, metalloproteinases, cystein-rich peptides and lectins. Fifteen percent of ESTs are similar to cellular transcripts. Sequences without good matches corresponded to 11%. This investigation provides the first global view of cDNAs from Tityus stigmurus. This approach enables characterization of a large number of venom gland component molecules, which belong either to known or atypical types of venom peptides and proteins from the Buthidae family

Transcriptoma diferencial entre células-tronco mesenquimais humanas jovens e senescentes

Human mesenchymal stem cells (MSC) are powerful sources for cell therapy in regenerative medicine. The long time cultivation can result in replicative senescence or can be related to the emergence of chromosomal alterations responsible for the acquisition of tumorigenesis features in vitro. In this study, for the first time, the expression profile of MSC with a paracentric chromosomal inversion (MSC/inv) was compared to normal karyotype (MSC/n) in early and late passages. Furthermore, we compared the transcriptome of each MSC in early passages with late passages. MSC used in this study were obtained from the umbilical vein of three donors, two MSC/n and one MSC/inv. After their cryopreservation, they have been expanded in vitro until reached senescence. Total RNA was extracted using the RNeasy mini kit (Qiagen) and marked with the GeneChip ® 3 IVT Express Kit (Affymetrix Inc.). Subsequently, the fragmented aRNA was hybridized on the microarranjo Affymetrix Human Genome U133 Plus 2.0 arrays (Affymetrix Inc.). The statistical analysis of differential gene expression was performed between groups MSC by the Partek Genomic Suite software, version 6.4 (Partek Inc.). Was considered statistically significant differences in expression to p-value Bonferroni correction ˂.01. Only signals with fold change ˃ 3.0 were included in the list of differentially expressed. Differences in gene expression data obtained from microarrays were confirmed by Real Time RT-PCR. For the interpretation of biological expression data were used: IPA (Ingenuity Systems) for analysis enrichment functions, the STRING 9.0 for construction of network interactions; Cytoscape 2.8 to the network visualization and analysis bottlenecks with the aid of the GraphPad Prism 5.0 software. BiNGO Cytoscape pluggin was used to access overrepresentation of Gene Ontology categories in Biological Networks. The comparison between senescent and young at each group of MSC has shown that there is a difference in the expression parttern, being higher in the senescent MSC/inv group. The results also showed difference in expression profiles between the MSC/inv versus MSC/n, being greater when they are senescent. New networks were identified for genes related to the response of two of MSC over cultivation time. Were also identified genes that can coordinate functional categories over represented at networks, such as CXCL12, SFRP1, xvi EGF, SPP1, MMP1 e THBS1. The biological interpretation of these data suggests that the population of MSC/inv has different constitutional characteristics, related to their potential for differentiation, proliferation and response to stimuli, responsible for a distinct process of replicative senescence in MSC/inv compared to MSC/n. The genes identified in this study are candidates for biomarkers of cellular senescence in MSC, but their functional relevance in this process should be evaluated in additional in vitro and/or in vivo assays

Análise do transcriptoma das glândulas venenosas do escorpião Tityus stigmurus

In Brazil, accidents with scorpions are considered of medical importance, not only by the high incidence, but also for the potentiality of the venom from some species in determining severe clinical conditions. Tityus stigmurus is a widely distributed scorpion species in Northeastern Brazil and known to cause severe human envenomations, inducing pain, hyposthesia, edema, erythema, paresthesia, headaches and vomiting. The present study uses a transcriptomic approach to characterize the molecular repertoire from the non-stimulated venom gland of Tityus stigmurus scorpion. A cDNA library was constructed and 540 clones were sequenced and grouped into 37 clusters, with more than one EST (expressed sequence tag) and 116 singlets. Forty-one percent of ESTs belong to recognized toxin-coding sequences, with antimicrobial toxins (AMP-like) the most abundant transcripts, followed by alfa KTx- like, beta KTx-like, beta NaTx-like and alfa NaTx-like. Our analysis indicated that 34% include other possible venom molecules , whose transcripts correspond to anionic peptides, hypothetical secreted peptides, metalloproteinases, cystein-rich peptides and lectins. Fifteen percent of ESTs are similar to cellular transcripts. Sequences without good matches corresponded to 11%. This investigation provides the first global view of cDNAs from Tityus stigmurus. This approach enables characterization of a large number of venom gland component molecules, which belong either to known or atypical types of venom peptides and proteins from the Buthidae family

Transcriptoma diferencial entre células-tronco mesenquimais humanas jovens e senescentes

Human mesenchymal stem cells (MSC) are powerful sources for cell therapy in regenerative medicine. The long time cultivation can result in replicative senescence or can be related to the emergence of chromosomal alterations responsible for the acquisition of tumorigenesis features in vitro. In this study, for the first time, the expression profile of MSC with a paracentric chromosomal inversion (MSC/inv) was compared to normal karyotype (MSC/n) in early and late passages. Furthermore, we compared the transcriptome of each MSC in early passages with late passages. MSC used in this study were obtained from the umbilical vein of three donors, two MSC/n and one MSC/inv. After their cryopreservation, they have been expanded in vitro until reached senescence. Total RNA was extracted using the RNeasy mini kit (Qiagen) and marked with the GeneChip ® 3 IVT Express Kit (Affymetrix Inc.). Subsequently, the fragmented aRNA was hybridized on the microarranjo Affymetrix Human Genome U133 Plus 2.0 arrays (Affymetrix Inc.). The statistical analysis of differential gene expression was performed between groups MSC by the Partek Genomic Suite software, version 6.4 (Partek Inc.). Was considered statistically significant differences in expression to p-value Bonferroni correction ˂.01. Only signals with fold change ˃ 3.0 were included in the list of differentially expressed. Differences in gene expression data obtained from microarrays were confirmed by Real Time RT-PCR. For the interpretation of biological expression data were used: IPA (Ingenuity Systems) for analysis enrichment functions, the STRING 9.0 for construction of network interactions; Cytoscape 2.8 to the network visualization and analysis bottlenecks with the aid of the GraphPad Prism 5.0 software. BiNGO Cytoscape pluggin was used to access overrepresentation of Gene Ontology categories in Biological Networks. The comparison between senescent and young at each group of MSC has shown that there is a difference in the expression parttern, being higher in the senescent MSC/inv group. The results also showed difference in expression profiles between the MSC/inv versus MSC/n, being greater when they are senescent. New networks were identified for genes related to the response of two of MSC over cultivation time. Were also identified genes that can coordinate functional categories over represented at networks, such as CXCL12, SFRP1, xvi EGF, SPP1, MMP1 e THBS1. The biological interpretation of these data suggests that the population of MSC/inv has different constitutional characteristics, related to their potential for differentiation, proliferation and response to stimuli, responsible for a distinct process of replicative senescence in MSC/inv compared to MSC/n. The genes identified in this study are candidates for biomarkers of cellular senescence in MSC, but their functional relevance in this process should be evaluated in additional in vitro and/or in vivo assays

Avaliação funcional e estrutural de um novo peptídeo antimicrobiano do escorpião Tityus stigmurus

In Brazil, there is a high incidence of venomous animals. Among them, scorpions are highlighted by their medical importance, and for being their venom a source of several molecules with biological and pharmacological activity not yet fully understood, including several bioactive peptides. Antimicrobial peptides (AMPs) are components of the immune system in prokaryotes and eukaryotes, used in the first line of defense against microorganisms. In the present study, we characterized the first PAM previously identified through transcriptome of the venom gland of the scorpion Tityus stigmurus, named Stigmurin. The characteristics of Stigmurin were investigated by computational modeling and construction of dendrogram. In vitro tests investigated the antibacterial, antifungal, haemolytic and cytotoxic effects of crude venom and Stigmurin. In addition, the structural characteristics of Stigmurin were investigated by circular dochroism in water, 2, 2 , 2- trifluoethanol (TFE) and sodium dodecyl sulfate (SDS) and the models were refined by molecular dynamics simulations. The results showed that the selected sequence encodes a mature protein of 17 amino acid residues and the dendrogram reveals a case of convergent evolution. The crude venom showed no antimicrobial activity, however, Stigmurin exhibited a broad spectrum of antibacterial activity, with minimal inhibitory concentrations (MIC) ranging from 31.25 and 250 µg/mL for different strains, while the hemolytic activity at these concentrations was low. In cytotoxicity studies, the crude venom was unable to reduce cell viability in VERO E6 cells; in contrast, its activity in SiHa cells was significantly higher, corresponding to IC50 of 3.6 µg/mL. For Stigmurin the concentration sable to decrease cell viability of Vero E6 and SiHa cells in 50% were 275.67 µg/mL and 212.54 µg/mL, respectively. The dichroism spectra revealed the conformational flexibility, with predominating extended and β–sheet structures, as well as a remark able renaturation ability. The results suggest that Stigmurin could be considered as a potential antiinfective drug

Avaliação do efeito da inibição do reparo de sítios abásicos na resposta inflamatória celular

Base excision repair (BER) proteins has been associated with functions beyond DNA repair. Apurynic/apyrimidinic endonuclease 1 (APE1) is a multifunctional protein involved in a plethora of cellular activities, such as redox activation of transcription factors, RNA processing and DNA repair. Some studies have described the action of the protein 8-oxoguanine (OGG1) in correcting oxidized lesions in promoters as a step in the transcription of pro-inflammatory cytokines. Despite being especially important in redox activation of transcription factors such as nuclear factor κB (NF-κB) and AP- 1, the repair activity of APE1 has not yet been associated with the inflammatory response. In this study, experimental and bioinformatic analysis approaches have been used to investigate the relationship between inhibition of the repair of abasic sites in DNA by MX, a synthetic molecule designed to inhibt the repair activity of APE1, and the modulation of the inflammatory response. The results showed that treatment of monocytes with lipopolysaccharide (LPS) and MX reduced the expression of cytokines, chemokines and toll-like receptors, and negatively regulated biological immune processes, as macrophages activation, and NF-κB and tumor necrosis factor (TNF-α) and interferon pathways, without inducing cell death. The transcriptomic analysis suggests that LPS/MX treatment induces mitochondrial dysfunction, endoplasmic reticulum stress and activation of autophagy pathways, probably activated by impairment of cellular energy and/or the accumulation of nuclear and mitochondria DNA damage. Additionally, it is proposed that the repair activity of APE1 is required for transcription of inflammatory genes by interaction with abasic sites at specific promoters and recruitment of transcriptional complexes during inflammatory signaling. This work presents a new perspective on the interactions between the BER activity and the modulation of inflammatory response, and suggests a new activity for APE1 protein as modulator of the immune response in a redox-independent manner.

Síndrome de Guillain-Barré: epidemiologia, prognóstico e fatores de risco

Introduction. Guillain-Barré syndrome (GBS) is an immune-mediated polyneuropathy and the principal cause of acute neuromuscular paralysis. The most prominent GBS subtypes are: acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), acute motor-sensory axonal neuropathy (AMSAN) and Fisher syndrome (FS). Differences in geographical distribution of variants have been reported. In Brazil, there are few studies describing the characteristics of GBS, but none on the frequency of GBS variants and their clinical manifestations. Infection-induced aberrant immune response resulting from molecular mimicry and formation of cross-reacting antibodies, contribute to complement activation. Functional biallelic polymorphism in immunoglobulin receptors that influence the affinity of IgG subclasses and the type of immune response have been described, suggesting genetic susceptibility to developing disease. It remains unclear whether individuals carrying different FCGR alleles have differential risk for GBS and⁄or disease severity. The goals of this study were: (1) To characterize GBS and describe the clinical findings in a cohort of patients with GBS from the state of Rio Grande do Norte, Brazil; (2) to determine whether polymorphism in FCGR were associated with development of GBS, and (3) to tease out whether the global gene expression studies could be a tool to identify pathways and transcriptional networks which could be regulated and decrease the time of disease. Methods. Clinical and laboratory data for 149 cases of GBS diagnosed from 1994 to 2013 were analyzed. Genomic DNA and total RNA were extracted from whole blood. Antigangliosides antibodies were determined in the sera. In addition, we also assessed whether FCGR polymorphism are present in GBS (n=141) and blood donors (n=364), and global gene expressions were determined for 12 participants with GBS. Blood samples were collected at the diagnosis and post-recovery. Results. AIDP was the most frequent variant (81.8%) of GBS, followed by AMAN (14.7%) and AMSAN (3.3%). The incidence of GBS was 0.3 ⁄ 100,000 people for the state of Rio Grande do Norte and cases occurred at a younger age. GBS was preceded by infections, with the axonal variant associated with episodes of diarrhea (P = 0.025). Proximal weakness was more frequent in AIDP, and distal weakness predominant in the axonal variant. Compared to 42.4% of cases with AIDP (P<0.0001), 84.6% of cases with the axonal variant had nadir in <10 days. Individuals with the axonal variant took longer to recover deambulation (P<0.0001). The mortality of GBS was 5.3%. A worse outcome was related to an axonal variant (OR17.063; P=0.03) and time required to improve one point in the Hughes functional scale (OR 1.028; P=0.03). The FCGR genotypes and allele frequencies did not differ significantly between the patients with GBS and the controls (FCGR2A p=0.367 and FCGR3A p=0.2430). Global gene expression using RNAseq showed variation in transcript coding for protein isoforms during acute phase of disease. Conclusions. The annual incidence of GBS was 0.3 per 100,00 and there was no seasonal pattern. A predominance of the AIDP variant was seen, and the incidence of the disease decreased with age. The distribution of weakness is a function of the clinical variants, and individuals with the axonal variant had a poorer prognosis. Early diagnosis and variant identification leads to proper intervention decreasing in long-term morbidity. FCGR polymorphisms do not seem to influence susceptibility to GBS in this population. This study found deregulated genes and signs of transcriptional network alterations during the acute and recovery phases in GBS. Identification of pathways altered during disease might be target for immune regulation and with potential to ameliorate symptoms.

Avaliação da atividade antimicrobiana das defensinas recombinantes de ervilha (drr230a) e café (cd1) produzidas em Pichia pastoris

The inefficiency of chemical pesticides to control phytopathogenic fungi in agriculture and the frequent incidence of human diseases caused by bacteria which are resistant to antibiotics lead to the search for alternative antimicrobial compounds. In this context, plant defensins are a promising tool for the control of both plant and human pathogenic agents. Plant defensins are cationic peptides of about 50 amino acid residues, rich in cysteine and whose tridimensional structure is considerably conserved among different plant species. These antimicrobial molecules represent an important innate component from plant defense response against pathogens and are expressed in various plant tissues, such as leaves, tubers, flowers, pods and seeds. The present work aimed at the evaluation of the antimicrobial activity of two plant defensins against different phytopathogenic fungi and pathogenic bacteria to humans. The defensin Drr230a, whose gene was isolated from pea (Pisum sativum), and the defensin CD1,whose gene was identified within coffee (Coffea arabica) transcriptome, were subcloned in yeast expression vector and expressed in Pichia pastoris. The gene cd1 was subcloned as two different recombinant forms: CD1tC, containing a six-histidine sequence (6xHis) at the peptide C-terminal region and CD1tN, containing 6xHis coding sequence at the N-terminal region. In the case of the defensin Drr230a, the 6xHis coding sequence was inserted only at the N-terminal region. Assays of the antimicrobial activity of the purified recombinant proteins rDrr230a and rCD1 against Phakopsora pachyrhizi, causal agent of soybean Asian rust, were performed to analyze the in vitro spore germination inhibition and disease severity caused by the fungus in planta. Both recombinant defensins were able to inhibit P. pachyrhizi uredospore germination, with no difference between the antimicrobial action of either CD1tC or CD1tN. Moreover, rDrr230a and rCD1 drastically reduced severity of soybean Asian rust, as demonstrated by in planta assays. In spite of the fact that rCD1 was not able to inhibit proliferation of the human pathogenic bacteria Staplylococcus aureus and Klebsiella pneumoniae, rCD1 was able to inhibit growth of the phytopathogenic fungus Fusarium tucumaniae, that causes soybean sudden death syndrome. The obtained results show that these plant defensins are useful candidates to be used in plant genetic engineering programs to control agriculture impacting fungal diseases.