La Bioética y el destino de los embriones congelados

Fil: Theas, María Susana. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Reproducción; ArgentinaEn el presente trabajo se analizan los problemas morales involucrados en el destino de los embriones congelados a la luz de los principios de la bioética, autonomía, beneficencia, no maleficencia y justicia, teniendo en cuenta a la pareja infértil, al médico, como también al embrión en cuestión

Inhibition of NOS-NO System Prevents Autoimmune Orchitis Development in Rats: Relevance of NO Released by Testicular Macrophages in Germ Cell Apoptosis and Testosterone Secretion.

Although the testis is considered an immunoprivileged organ it can orchestrate immune responses against pathological insults such as infection and trauma. Experimental autoimmune orchitis (EAO) is a model of chronic inflammation whose main histopathological features it shares with human orchitis. In EAO an increased number of macrophages infiltrate the interstitium concomitantly with progressive germ cell degeneration and impaired steroidogenesis. Up-regulation of nitric oxide (NO)-NO synthase (NOS) system occurs, macrophages being the main producers of NO.The aim of our study was to evaluate the role of NO-NOS system in orchitis development and determine the involvement of NO released by testicular macrophages on germ cell apoptosis and testosterone secretion.EAO was induced in rats by immunization with testicular homogenate and adjuvants (E group) and a group of untreated normal rats (N) was also studied. Blockage of NOS by i.p. injection of E rats with a competitive inhibitor of NOS, L-NAME (8mg/kg), significantly reduced the incidence and severity of orchitis and lowered testicular nitrite content. L-NAME reduced germ cell apoptosis and restored intratesticular testosterone levels, without variations in serum LH. Co-culture of N testicular fragments with testicular macrophages obtained from EAO rats significantly increased germ cell apoptosis and testosterone secretion, whereas addition of L-NAME lowered both effects and reduced nitrite content. Incubation of testicular fragments from N rats with a NO donor DETA-NOnoate (DETA-NO) induced germ cell apoptosis through external and internal apoptotic pathways, an effect prevented by N-acetyl-L-cysteine (NAC). DETA-NO inhibited testosterone released from Leydig cells, whereas NAC (from 2.5 to 15 mM) did not prevent this effect.We demonstrated that NO-NOS system is involved in the impairment of testicular function in orchitis. NO secreted mainly by testicular macrophages could promote oxidative stress inducing ST damage and interfering in Leydig cell function

Papel del péptido mitocondrial humanina como blanco terapéutico en cáncer y neurodegeneración

Humanin is a mitochondrial-derived peptide which shows robust protective effects against large series of cytotoxic stimuli in many cell types. This makes it an interesting therapeutic target for many diseases, including cancer and neurodegenerative diseases, among others. Furthermore, this peptide could be used as a biomarker for such diseases. Over the last decade, humanin analogs and peptide mimetics have been developed, which exert highly promising results in preclinical models. Besides, the therapeutic potential of gene therapy vectors that overexpress or silence endogenous humanin is under evaluation. Nonetheless, its possible role in cancer progression and chemoresistance are critical issuesto be addressed before translating these therapeutic approaches to the clinic. All these matters will be covered in this review.La humanina es un péptido derivado de la mitocondria con efectos protectores robustos contra una gran variedad de estímulos citotóxicos en diversos tipos celulares. Esto la convierte en un blanco terapéutico interesante para muchas enfermedades, como el cáncer y enfermedades neurodegenerativas, entre otras. Además, este péptido podría utilizarse como un biomarcador en estas enfermedades. Durante la última década, han sido desarrollados análogos y péptido-miméticos de la humanina que muestran resultados prometedores en modelos preclínicos. A su vez, también se está explorando el potencial terapéutico de vectores de terapia génica que puedan sobreexpresar o silenciar la humanina endógena.Varios puntos importantes a considerar antes de trasladar estas estrategias terapéuticas a la clínica son su posible papel en la progresión del cáncer y la eventual generación de quimiorresistencia. Todos estos temas serán abordados en este artículo de revisión

Unraveling the effect of the inflammatory microenvironment in spermatogenesis progression

Experimental autoimmune orchitis (EAO) is a chronic inflammatory disorder that causes progressive spermatogenic impairment. EAO is characterized by high intratesticular levels of nitric oxide (NO) and tumor necrosis factor alpha (TNFα) causing germ cell apoptosis and Sertoli cell dysfunction. However, the impact of this inflammatory milieu on the spermatogenic wave is unknown. Therefore, we studied the effect of inflammation on spermatogonia and preleptotene spermatocyte cell cycle progression in an EAO context and through the intratesticular DETA-NO and TNFα injection in the normal rat testes. In EAO, premeiotic germ cell proliferation is limited as a consequence of the undifferentiated spermatogonia (CD9+) cell cycle arrest in G2/M and the reduced number of differentiated spermatogonia (c-kit+) and preleptotene spermatocytes that enter in the meiotic S-phase. Although inflammation disrupts spermatogenesis in EAO, it is maintained in some seminiferous tubules at XIV and VII–VIII stages of the epithelial cell cycle, thereby guaranteeing sperm production. We found that DETA-NO (2 mM) injected in normal testes arrests spermatogonia and preleptotene spermatocyte cell cycle; this effect reduces the number of proliferative spermatogonia and the number of preleptotene spermatocytes in meiosis S-phase (36 h after). The temporal inhibition of spermatogonia clonal amplification delayed progression of the spermatogenic wave (5 days after) finally altering spermatogenesis. TNFα (0.5 and 1 µg) exposure did not affect premeiotic germ cell cycle or spermatogenic wave. Our results show that in EAO the inflammatory microenvironment altered spermatogenesis kinetics through premeiotic germ cell cycle arrest and that NO is a sufficient factor contributing to this phenomenon.Fil: Ferreiro, María Eugenia. University of Queensland; Australia. The University of Queensland; AustraliaFil: Mendez, Cinthia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Glienke, Leilane. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Sobarzo, Cristian Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Ferraris, María Jimena. Stockholms Universitet; SueciaFil: Pisera, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Lustig, Livia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Jacobo, Patricia Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Theas, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

Mitochondrial-derived peptide humanin as therapeutic target in cancer and degenerative diseases

Introduction: Mitochondrial-derived peptides (MDPs) are encoded within the mitochondrial genome. They signal within the cell or are released to act as autocrine/paracrine/endocrine cytoprotective factors playing a key role in the cellular stress response. The first reported and better characterized MDP is humanin (HN), which exerts robust protective effects against a myriad of cytotoxic stimuli in many cell types. These effects have led to the evaluation of HN and its analogs as therapeutic targets for several chronic diseases. Areas covered: We describe the latest findings on the mechanism of action of HN and discuss the role of HN as therapeutic target for neurodegenerative and cardiovascular diseases, diabetes, male infertility, and cancer. Since HN can be detected in circulation, we also depict its value as a biomarker for these diseases. Expert opinion: HN analogs and peptide mimetics have been developed over the last decade and show promising results in preclinical models of degenerative diseases. Local administration of gene therapy vectors that overexpress or silence endogenous HN could also hold therapeutic potential. Controversy on the role of HN in cancer progression and chemoresistance should be addressed before the translation of these therapeutic approaches.Fil: Zuccato, Camila Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Asad, Antonela Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Nicola Candia, Alejandro Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Gottardo, María Florencia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Moreno Ayala, Mariela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of California; Estados UnidosFil: Theas, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Seilicovich, Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Candolfi, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

The inflammatory mediators TNFα and nitric oxide arrest spermatogonia GC-1 cell cycle

During an inflammatory process of the testis, the network of somatic, immune, and germ cell interactions is altered leading to organ dysfunction. In testicular biopsies of infertile men, spermatogenesis impairment is associated with reduced spermatogonia proliferation, increased number of immune cells, and content of pro-inflammatory cytokines. TNFα-TNFR and nitric oxide (NO)-NO synthase systems are up-regulated in models of testicular damage and in human testis with maturation arrest. The purpose of this study was to test the hypothesis that TNFα-TNFR system and NO alter the function of spermatogonia in the inflamed testis. We studied the effect of TNFα and NO on GC-1 spermatogonia cell cycle progression and death by flow cytometry. GC-1 cells expressed TNFR1 and TNFR2 (immunofluorescence). TNFα (10 and 50 ng/ml) and DETA-Nonoate (0.5 and 2 mM), a NO releaser, increased the percentage of cells in S-phase of the cell cycle and reduced the percentage in G1, inducing also cell apoptosis. TNFα effect was not mediated by oxidative stress unlike NO, since the presence of N-acetyl-L-cysteine (2.5 and 5.0 mM) prevented NO induced cell cycle arrest and death. GC-1 spermatogonia overpass NO induced cell cycle arrest but no TNFα, since after removal of NO, spermatogonia progressed through the cell cycle. We propose TNFα and NO might contribute to impairment of spermatogenesis by preventing adequate functioning of the spermatogonia population. Our results showed that TNFα and NO impaired spermatogonia cell cycle, inducing GC-1 arrest in the S phase.Fil: Ferreiro, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Amarilla, María Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Glienke, Leilane. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Mendez, Cinthia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Gonzalez, Candela Rocio. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Jacobo, Patricia Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Sobarzo, Cristian Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: de Laurentis, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Ferraris, Maria Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Theas, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

JAK2/STAT5 pathway mediates prolactin-induced apoptosis of lactotropes

Prolactinomas are increasingly viewed as a "problem of signal transduction." Consequently, the identification of factors and signaling pathways that control lactotrope cell turnover is needed in order to encourage new therapeutic developments. We have previously shown that prolactin (PRL) acts as a proapoptotic and antiproliferative factor on lactotropes, maintaining anterior pituitary cell homeostasis, which contrasts with the classical antiapoptotic and/or proliferative actions exerted by PRL in most other target tissues. We aimed to investigate the PRLR-triggered signaling pathways mediating these nonclassical effects of PRL in the pituitary. Our results suggest that (i) the PRLR/Jak2/STAT5 pathway is constitutively active in GH3 cells and contributes to PRL-induced apoptosis by increasing the Bax/Bcl-2 ratio, (ii) PRL inhibits ERK1/2 and Akt phosphorylation, thereby contributing to its proapoptotic effect, and (iii) the PI3K/Akt pathway participates in the PRL-mediated control of lactotrope proliferation. We hypothesize that the alteration of PRL actions in lactotrope homeostasis due to the dysregulation of any of the mechanisms of actions described above may contribute to the pathogenesis of prolactinomas.Fil: de Dios, Nataly. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Orrillo, Santiago Jordi. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Irizarri, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Theas, María Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Boutillon, Florence. Inserm; FranciaFil: Candolfi, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Seilicovich, Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Goffin, Vincent. Inserm; FranciaFil: Pisera, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Ferraris, Maria Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

Effect of DETA-NO on caspase 8 activation.

<p>Testicular fragments obtained from normal rats were incubated with medium containing or not DETA-NO for 18h. A) Representative Western blot of caspase 8 content in cytosolic lysates B) Semiquantitative results of caspase 8 fragment obtained by densitometric analysis of Western blots. A.U.: arbitrary units. Data from medium was arbitrarily set at 1. Each bar represents mean±SEM of 10 rats. *** p<0.01 vs. medium. One sample t Test.</p

Effect of NO released by testicular macrophages on apoptotic mitochondrial pathway activation.

<p>Testicular fragments from normal rats incubated with medium alone or testicular macrophages (TM) isolated from EAO rats in the presence of D-NAME (2mM) or L-NAME (2mM) for 18h. Representative Western blots and semiquantitative results obtained by densitometric analysis of Western blots. A.U.: arbitrary units. Data from medium were arbitrarily set at 1. A) Cytochrome c content in the cytosolic fraction. B) Ratio of Bax/Bcl-2 content in the mitochondrial fraction. C) Caspase 9 processing in the cytosolic fraction. Each bar represents mean±SEM of three rats in three independent experiments.</p

Effect of DETA-NO on testosterone secretion.

<p>A) Determination of nitrites generated from different concentrations of DETA-NO in DMEM/F12 medium without phenol red. Each circle represents mean of three wells (B) Testicular fragments obtained from normal rats were incubated with media containing or not DETA-NO in the presence or absence of NAC for 18h. Testosterone content in the media was evaluated by RIA. Each bar represents mean±SEM (n = 5–8 rats) from two independent experiments. ***p<0.001 and ^Δp<0.05 vs. medium. Bonferroni Multiple Comparison Test.</p