IKZF1plus is a frequent biomarker of adverse prognosis in Mexican pediatric patients with B-acute lymphoblastic leukemia.

Background: Recurrent genetic alterations contributing to leukemogenesis have been identified in pediatric B-cell Acute Lymphoblastic Leukemia (B-ALL), and some are useful for refining classification, prognosis, and treatment selection. IKZF1plus is a complex biomarker associated with a poor prognosis. It is characterized by IKZF1 deletion coexisting with PAX5, CDKN2A/2B, or PAR1 region deletions. The mutational spectrum and clinical impact of these alterations have scarcely been explored in Mexican pediatric patients with B-ALL. Here, we report the frequency of the IKZF1plus profile and the mutational spectrum of IKZF1, PAX5, CDKN2A/2B, and ERG genes and evaluate their impact on overall survival (OS) in a group of patients with B-ALL. Methods: A total of 206 pediatric patients with de novo B-ALL were included. DNA was obtained from bone marrow samples at diagnosis before treatment initiation. A custom-designed next-generation sequencing panel was used for mutational analysis. Kaplan-Meier analysis was used for OS estimation. Results: We identified the IKZF1plus profile in 21.8% of patients, which was higher than that previously reported in other studies. A significantly older age (p=0.04), a trend toward high-risk stratification (p=0.06), and a decrease in 5-year Overall Survival (OS) (p=0.009) were observed, although heterogeneous treatment protocols in our cohort would have impacted OS. A mutation frequency higher than that reported was found for IKZF1 (35.9%) and CDKN2A/2B (35.9%) but lower for PAX5 (26.6%). IKZF1MUT group was older at diagnosis (p=0.0002), and most of them were classified as high-risk (73.8%, p=0.02), while patients with CDKN2A/2BMUT had a higher leukocyte count (p=0.01) and a tendency toward a higher percentage of blasts (98.6%, >50% blasts, p=0.05) than the non-mutated patients. A decrease in OS was found in IKZF1MUT and CDKN2A/2BMUT patients, but the significance was lost after IKZF1plus was removed. Discussion: Our findings demonstrated that Mexican patients with B-ALL have a higher prevalence of genetic markers associated with poor outcomes. Incorporating genomic methodologies into the diagnostic process, a significant unmet need in low- and mid-income countries, will allow a comprehensive identification of relevant alterations, improving disease classification, treatment selection, and the general outcome.

Design, synthesis, and in vitro antiplatelet aggregation activities of taiwanin C.

Total synthesis of taiwanin C was realised efficiently in a global yield of 52%. Taiwanin C in aggregation assays inhibited platelet aggregation in a concentration-dependent manner with an IC50 of 0.46 µM after exposure of human platelet to AA. Similarly, to AA, taiwanin C inhibited significantly TRAP-6-induced platelet aggregation with IC50 of 0.56 µM. Molecular docking studies were carried out using the molecular target the COX-1, COX-2 and PAR-1 proteins. These studies suggest that taiwanin inhibits COX-1 more strongly than COX-2. Taiwanin C showed better antiplatelet action in the presence of TRAP-6 than indomethacin and molecular docking studies suggest different mechanisms of action for the two compounds on PAR-1. These results demonstrate that taiwanin C acts very efficiently in two different signaling pathways of platelet aggregation. Although preliminary, these results indicate that taiwanin C has potential for further studies on its use for the development of new antiplatelet.

TR47, a PAR1-based peptide, inhibits melanoma cell migration in vitro and metastasis in vivo.

Activated Protein C (APC) is a serine-protease that displays antithrombotic and anti-inflammatory properties. In addition, cleavage of protease-activated receptor 1 (PAR1) by APC exerts endothelial cytoprotective actions. The effects of APC on endothelial cells may be reproduced by TR47, a PAR1-based peptide that mimics the novel N-terminus of PAR1 generated upon cleavage at Arg-46 by APC. In this study we demonstrate that wild-type APC and its signaling-proficient mutant, APC-2Cys (which has dramatically reduced anticoagulant activity), display similar inhibitory effects towards the transendothelial migration of A375 human melanoma cells. Consistent with this observation, APC and APC-2Cys significantly reduced the in vivo metastatic potential of the B16F10 murine melanoma cells. TR47 recapitulated the in vitro and in vivo protective profiles of APC and APC-2Cys. Treatment of EA.hy926 endothelial cells with TR47 (20 µM) significantly decreased the A375 cell migration. In addition, treatment of C57/BL6 mice with a single TR47 dose (125 µg/animal) strongly reduced the metastatic burden of B16F10 cells. Together, our results suggest that protection of the endothelial barrier by APC/TR47-mediated signaling pathways might be a valuable therapeutic approach to prevent metastasis.

Platelets: an outlook from biology through evidence-based achievements in critical care.

Since the original observations by Bizzozero and Osler, we have seen tremendous advances in the understanding of platelets far beyond haemostasis and the restoration of injured endothelium. In this mini-review on platelets, we will briefly outline their historical description and the importance of their evolution, focusing on a 450 million years old living fossil of Limulus polyphemus, a marine chelicerate arthropod, which helped researchers explain the basis for the immunity role of platelets and make correlations with platelet ultrastructure and function. In addition, the impact of the Limulus Amoebocyte Lysate (LAL) test for modern medicine is highlighted. The role of platelets in cardiovascular diseases, their relevance in arterial and venous thrombosis, and the utilization of antithrombotic drugs as therapeutic agents are also reported. Furthermore, platelet receptors are crucial in aggravating or mitigating other diseases, such as cancer and infections, which can recruit cells and have numerous interactions in a process recently coined "NETosis formation", which is also briefly depicted.

Un caso de deleción parcial 1p36. 1 y trisomía parcial 6p diagnosticadas por cariotipo / A case of partial 1p36. 1 deletion and partial trisomy 6p diagnosed by karyotype

La deleción de la región cromosómica 1p36 es una de las anomalías subteloméricas más frecuentes y causa rasgos dismórficos distintivos. Por otro lado, la trisomía distal del brazo corto del cromosoma 6 es una anormalidad cromosómica poco frecuente de fenotipo variable. Objetivo: Presentar el caso de un paciente con ambas alteraciones cromosómicas, y resaltar la vigencia e importancia del cariotipo como herramienta diagnóstica en dismorfología. Caso clínico: Lactante de 2 meses de edad con múltiples anomalías craneofaciales, hemangioma en la nuca, fosita sacra, acortamiento rizomélico, pies y manos pequeños, criptorquidia unilateral izquierda e hipotonía. Además, antecedente de restricción del crecimiento intrauterino. Producto del octavo embarazo de una mujer G8A7C1 de 28 años. Con estos hallazgos inespecíficos en el fenotipo se solicitó cariotipo que mostró una deleción parcial de 1p36.1 y una trisomía parcial de cromosoma 6p. Conclusión: El cariotipo convencional sigue siendo una herramienta importante para el etiológico en pacientes con anomalías congénitas (múltiples), mostrando en este caso una deleción parcial de 1p36.1 y una trisomía parcial de cromosoma 6p, alteraciones cromosómicas estructurales.

The deletion of chromosomal region 1p36 is one of the most common sub-telomeric microdeletion syndromes and has distinctive dysmorphic features. On the other hand, partial trisomy of the short arm of chromosome 6 is a rare chromosomal abnormality with a variable phenotype. Objective: To report a case with both chromosome abnormalities, and to highlight the importance of the karyotype as a diagnostic tool in dysmorphology. Clinical case: The case of is presented of a two month-old infant with several craniofacial anomalies, neck haemangioma, sacral pit, rhizomelic shortening, small hands and feet, left unilateral cryptorchidism, and hypotonia. The infant also suffered intrauterine growth restriction and is the product of the eighth pregnancy of a 28 years old woman. Due to the unspecific findings in phenotype, a karyotype was requested, which showed a partial deletion of 1p36.1 and a partial trisomy of chromosome 6. Conclusion: The development of new techniques in molecular biology has improved diagnostic possibilities in medical genetics. However, the traditional karyotype remains as an important diagnostic tool in patients with multiple congenital anomalies.

[A case of partial 1p36.1 deletion and partial trisomy 6p diagnosed by karyotype]. / Un caso de deleción parcial 1p36.1 y trisomía parcial 6p diagnosticadas por cariotipo.

The deletion of chromosomal region 1p36 is one of the most common sub-telomeric microdeletion syndromes and has distinctive dysmorphic features. On the other hand, partial trisomy of the short arm of chromosome 6 is a rare chromosomal abnormality with a variable phenotype. OBJECTIVE: To report a case with both chromosome abnormalities, and to highlight the importance of the karyotype as a diagnostic tool in dysmorphology. CLINICAL CASE: The case of is presented of a two month-old infant with several craniofacial anomalies, neck haemangioma, sacral pit, rhizomelic shortening, small hands and feet, left unilateral cryptorchidism, and hypotonia. The infant also suffered intrauterine growth restriction and is the product of the eighth pregnancy of a 28 years old woman. Due to the unspecific findings in phenotype, a karyotype was requested, which showed a partial deletion of 1p36.1 and a partial trisomy of chromosome 6. CONCLUSION: The development of new techniques in molecular biology has improved diagnostic possibilities in medical genetics. However, the traditional karyotype remains as an important diagnostic tool in patients with multiple congenital anomalies.

Proteoforms of the platelet-aggregating enzyme PA-BJ, a serine proteinase from Bothrops jararaca venom.

Snake venoms contain serine proteinases that are functionally similar to thrombin and specifically cleave fibrinogen to convert it into fibrin or activate platelets to aggregation. PA-BJ is a serine proteinase from Bothrops jararaca venom that promotes platelet aggregation and this effect is mediated by the G-coupled protein receptors PAR1 and PAR4. In this study we describe an improved procedure to obtain PA-BJ from B. jararaca venom that uses less chromatographic steps, and, interestingly, results in the isolation of eight proteoforms showing slightly different pIs and molecular masses due to variations in their glycosylation levels. The identity of the isolated PA-BJ forms (1-8) was confirmed by mass spectrometry, and they showed similar platelet-activating activity on washed platelet suspensions. N- and O-deglycosylation of PA-BJ 1-8 under denaturing conditions generated variable electrophoretic profiles and showed that some forms were resistant to complete deglycosylation. Furthermore, N- and O-deglycosylation under non-denaturing conditions also showed different electrophoretic profiles between the PA-BJ forms and caused partial loss of their ability to cleave a recombinant exodomain of PAR1 receptor. In parallel, three cDNAs encoding PA-BJ-like enzymes were identified by pyrosequencing of a B. jararaca venom gland library constructed with RNA from a single specimen. Taken together, our results suggest that PA-BJ occurs in the B. jararaca venom in multiple proteoforms displaying similar properties upon platelets regardless of their variable isoelectric points, molecular masses, carbohydrate moieties and susceptibility to the activity of glycosidases, and highlight that variability of specific venom components contributes to venom proteome complexity.

Influence of parstatin on experimental periodontal disease and repair in rats.

BACKGROUND: Parstatin is a 41-amino acid peptide, formed by proteolytic cleavage on activation of the protease activated receptor-1, with antiangiogenic properties. The purpose of this study is to evaluate the influence of synthetic parstatin on experimental periodontal disease and repair in rats. METHODS: Ligature-induced periodontitis was established in rats and the influence of parstatin administration was assessed after 8 and 15 days for periodontal disease and 24 hours and 8 days after repair after ligature removal. RESULTS: Parstatin administration significantly inhibited gingival myeloperoxidase activity, interleukin (IL)-1ß, tumor necrosis factor-α, and IL-6 levels and led to suppression of macrophages and collagen degradation. At periodontal tissues under repair, parstatin increased the gingival levels of endostatin and decreased vascular endothelial growth factor expression and blood vessel number but did not influence histologic healing. In addition, the tomographic linear bone loss was significantly reduced at 15 days of periodontitis when the rats were treated with parstatin compared to their respective phosphate-buffered saline-treated controls. CONCLUSIONS: Parstatin suppresses the periodontal tissue breakdown followed by experimental periodontitis in rats and did not impair periodontal tissue repair, despite its antiangiogenic effect. Parstatin may represent a novel approach to modulate host response in chronic periodontal disease.

Inibição do receptor tipo-1 ativado por protease (PAR¹) na doença e reparo periodontal / Type 1 protease-activated receptor (PAR 1 ) inhibition on periodontal disease and repair

A sinalização celular por PAR¹ tem mostrado influenciar uma ampla gama de respostas patofisiológicas, incluindo ativação plaquetária, crescimento tumoral, inflamação e metástases. Baseando-se nisto, o objetivo do presente estudo foi avaliar o efeito do Parstatin, droga que tem ação biológica oposta àquela desencadeada pela ativação do PAR¹, durante o processo de indução e reparo da inflamação. Foi utilizado um modelo de periodontite experimental em ratos através da instalação de ligaduras de fio de algodão nos segundos molares superiores. Para isto, 72 ratos foram separados aleatoriamente em 9 grupos com 8 animais cada e receberam as ligaduras e injeção de veículo ou Parstatin nos períodos de 7 e 14 dias para observar a ação da inibição deste receptor nos períodos de indução de inflamação e reparo. Após estes períodos, os animais foram sacrificados e tiveram as maxilas removidas, dissecadas e divididas ao meio para avaliação histológica e radiográfica a fim de caracterizar infiltrado de células inflamatórias e perda óssea ao redor dos dentes.

PAR¹ cell signaling has been shown to be involved in several pathophysiological responses including platelet activation, tumor growth, inflammation and metastasis. Based on this, the aim of the present study was to evaluate the influence of Parstatin, a drug that presents a biological effect opposed to that of PAR¹ receptor activation, on inflammation induction and repair processes. Rats were subjected to cotton ligature-induced periodontitis bilaterally on the second upper molar teeth. Seventy-two rats were randomly assigned to 9 groups (n=8/group) and received ligatures and injection of vehicle or Parstatin for 7 or 14 days for both inflammation and repair induction. After that, the animals were sacrificed and their maxilla removed, dissected and divided in two for histologic and radiographic evaluation to characterize inflammatory cell infiltrate and bone loss around teeth.