Discovery of allosteric regulators with clinical potential to stabilize alpha-L-iduronidase in mucopolysaccharidosis type I.

Mucopolysaccharidosis type I (MPS I) is an inherited lysosomal disease caused by lowered activity of the enzyme alpha-L-iduronidase (IDUA). Current therapeutic options show limited efficacy and do not treat some important aspects of the disease. Therefore, it may be advantageous to identify strategies that could improve the efficacy of existing treatments. Pharmacological chaperones are small molecules that protect proteins from degradation, and their use in combination with enzyme replacement therapy (ERT) has been proposed as an alternative therapeutic strategy. Using the SEE-Tx® proprietary computational drug discovery platform, a new allosteric ligand binding cavity in IDUA was identified distal from the active site. Virtual high-throughput screening of approximately 5 million compounds using the SEE-Tx® docking platform identified a subset of small molecules that bound to the druggable cavity and functioned as novel allosteric chaperones of IDUA. Experimental validation by differential scanning fluorimetry showed an overall hit rate of 11.4%. Biophysical studies showed that one exemplary hit molecule GT-01803 bound to (Kd = 22 µM) and stabilized recombinant human IDUA (rhIDUA) in a dose-dependent manner. Co-administration of rhIDUA and GT-01803 increased IDUA activity in patient-derived fibroblasts. Preliminary in vivo studies have shown that GT-01803 improved the pharmacokinetic (PK) profile of rhIDUA, increasing plasma levels in a dose-dependent manner. Furthermore, GT-01803 also increased IDUA enzymatic activity in bone marrow tissue, which benefits least from standard ERT. Oral bioavailability of GT-01803 was found to be good (50%). Overall, the discovery and validation of a novel allosteric chaperone for rhIDUA presents a promising strategy to enhance the efficacy of existing treatments for MPS I. The compound's ability to increase rhIDUA activity in patient-derived fibroblasts and its good oral bioavailability underscore its potential as a potent adjunct to ERT, particularly for addressing aspects of the disease less responsive to standard treatment.

Validation of a highly sensitive HaloTag-based assay to evaluate the potency of a novel class of allosteric ß-Galactosidase correctors.

Site-directed Enzyme Enhancement Therapy (SEE-Tx®) technology is a disease-agnostic drug discovery tool that can be applied to any protein target of interest with a known three-dimensional structure. We used this proprietary technology to identify and characterize the therapeutic potential of structurally targeted allosteric regulators (STARs) of the lysosomal hydrolase ß-galactosidase (ß-Gal), which is deficient due to gene mutations in galactosidase beta 1 (GLB1)-related lysosomal storage disorders (LSDs). The biochemical HaloTag cleavage assay was used to monitor the delivery of wildtype (WT) ß-Gal and four disease-related ß-Gal variants (p.Ile51Thr, p.Arg59His, p.Arg201Cys and p.Trp273Leu) in the presence and absence of two identified STAR compounds. In addition, the ability of STARs to reduce toxic substrate was assessed in a canine fibroblast cell model. In contrast to the competitive pharmacological chaperone N-nonyl-deoxygalactonojirimycin (NN-DGJ), the two identified STAR compounds stabilized and substantially enhanced the lysosomal transport of wildtype enzyme and disease-causing ß-Gal variants. In addition, the two STAR compounds reduced the intracellular accumulation of exogenous GM1 ganglioside, an effect not observed with the competitive chaperone NN-DGJ. This proof-of-concept study demonstrates that the SEE-Tx® platform is a rapid and cost-effective drug discovery tool for identifying STARs for the treatment of LSDs. In addition, the HaloTag assay developed in our lab has proved valuable in investigating the effect of STARs in promoting enzyme transport and lysosomal delivery. Automatization and upscaling of this assay would be beneficial for screening STARs as part of the drug discovery process.

Synthesis, biological evaluation and SAR studies of novel bicyclic antitumor platinum(IV) complexes.

The present study describes the synthesis, anticancer activity and SAR studies of novel platinum(IV) complexes having 1,2-bis(aminomethyl)carbobicyclic or oxabicyclic carrier ligands, bearing chlorido and/or hydroxido ligands in axial position and chlorido or malonato ligands in equatorial position (labile ligands). These complexes were synthetized with the aim of obtaining new anticancer principles more soluble in water and therefore more bioavailable. Several substitution patterns on the platinum atom have been designed in order to evaluate their antiproliferative activity and to establish structure-activity relationship rules. The synthesis of platinum(IV) complexes with axial hydroxyl ligands on the platinum(IV) were carried out by reaction of K2Pt(OH)2Cl4 with the corresponding diamines. The complexes with axial chlorido ligands on the platinum(IV) atom were synthesized by direct reaction of diamines with K2PtCl6. Carboxylated complexes were synthesized by the substitution reaction of equatorial chlorido ligands by silver dicarboxylates. The most actives complexes were those having malonate as a labile ligand, no matter of the structure of the carrier ligand. Regarding the influence of the structure of the non-labile 1,4-diamine carrier ligand on the cytotoxicity, it was found that the complexes having the more lipophilic and symmetrical bicyclo[2.2.2]octane framework were much more active than those having an oxygen or methylene bridge.

Conocimientos de la población sobre lepra / Knowledge of the population about leprosy

Se realizó un estudio observacional descriptivo de tipo transversal para investigar el nivel de conocimientos, que sobre la lepra, tiene la población en el municipio de Limonar, durante el período de Marzo a Diciembre de 2002. Participaron en el estudio 395 pacientes mayores de 15 años, que fueron seleccionados de la población del municipio mediante un diseño multietápico que incluyó la estratificación y el conglomerado. Los datos fueron procesados en el sistema estadístico SPSS-10. Se utilizaron técnicas estadísticas como el Chi cuadrado para explorar la asociación significativa entre variables. Se obtuvo como resultado que existe desconocimiento por parte de la población acerca de la enfermedad, ya que solamente el 17,97 por ciento de la población mostró conocimientos adecuados, y se encontró relación significativa entre este, el sexo femenino y la escolaridad. Sobre la base de los resultados se recomiendan las audiencias diana para una efectiva intervención educativa en la Atención Primaria de Salud en este municipio.

Conocimientos de los médicos de familia sobre lepra / Knoledge of the family physicians about leprosy

Se realizó un estudio observacional descriptivo de tipo transversal para investigar el nivel de conocimientos de los Médicos de Familia sobre la lepra en el municipio de Limonar, durante el período de marzo a diciembre de 2002. Participaron en el estudio 36 Médicos de Familia de consultorios pertenecientes al Policlínico Docente “Nelson Fernández” de Limonar. Los datos fueron procesados en el sistema estadístico SPSS-10. Se utilizaron técnicas estadísticas como el cálculo del Chi cuadrado y la prueba de Kruskall Wallis para explorar la asociación significativa entre variables y comparar promedios entre muestras independientes. Se obtuvo como resultado que existe desconocimiento por parte de los Médicos de Familia acerca de la enfermedad, ya que solamente la cuarta parte de ellos alcanzó la puntuación mínima indispensable considerada para realizar un diagnóstico y tratamiento correcto de la enfermedad. Se demostró la importancia de la especialización de los médicos en la consolidación y enriquecimiento de los conocimientos relacionados con esta enfermedad y su declinación con el decursar de los años de graduado. En base a los resultados se recomendaron las audiencias diana para una efectiva intervención educativa en la Atención Primaria de Salud en este municipio.

Miasis cutánea forunculoide: un caso diagnosticado en Cuba / Furunculoid cutaneous myasis: a case diagnosed in Cuba

En este trabajo se presenta un caso de miasis cutánea forunculoide diagnosticado en el Servicio de Dermatología del Hospital Universitario Comandante Faustino Pérez de la ciudad de Matanzas. La paciente adquirió esta dermatosis en Costa Rica, pero desarrolló el cuadro clínico típico en nuestro país, donde recibió tratamiento médico. Se describen las características de las miasis cutáneas y de los agentes que las producen, así como su distribución geográfica y las opciones terapéuticas ante estos casos. Este trabajo tiene especial interés para los médicos internacionalistas que brindan sus servicios en países donde estas enfermedades son frecuentes.