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1.
Dev Dyn ; 2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38546215

RESUMEN

BACKGROUND: Neuronal lamination is a hallmark of the mammalian central nervous system (CNS) and underlies connectivity and function. Initial formation of this tissue architecture involves the integration of various signaling pathways that regulate the differentiation and migration of neural progenitor cells. RESULTS: Here, we demonstrate that mTORC1 mediates critical roles during neuronal lamination using the mouse retina as a model system. Down-regulation of mTORC1-signaling in retinal progenitor cells by conditional deletion of Rptor led to decreases in proliferation and increased apoptosis during embryogenesis. These developmental deficits preceded aberrant lamination in adult animals which was best exemplified by the fusion of the outer and inner nuclear layer and the absence of an outer plexiform layer. Moreover, ganglion cell axons originating from each Rptor-ablated retina appeared to segregate to an equal degree at the optic chiasm with both contralateral and ipsilateral projections displaying overlapping termination topographies within several retinorecipient nuclei. In combination, these visual pathway defects led to visually mediated behavioral deficits. CONCLUSIONS: This study establishes a critical role for mTORC1-signaling during retinal lamination and demonstrates that this pathway regulates diverse developmental mechanisms involved in driving the stratified arrangement of neurons during CNS development.

2.
Dev Dyn ; 251(2): 321-335, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34148274

RESUMEN

BACKGROUND: The coordinated wiring of neurons, glia and endothelial cells into neurovascular units is critical for central nervous system development. This is best exemplified in the mammalian retina where interneurons, astrocytes and retinal ganglion cells sculpt their vascular environment to meet the metabolic demands of visual function. Identifying the molecular networks that underlie neurovascular unit formation is an important step towards a deeper understanding of nervous system development and function. RESULTS: Here, we report that cell-to-cell mTORC1-signaling is essential for neurovascular unit formation during mouse retinal development. Using a conditional knockout approach we demonstrate that reduced mTORC1 activity in asymmetrically positioned retinal ganglion cells induces a delay in postnatal vascular network formation in addition to the production of rudimentary and tortuous vessel networks in adult animals. The severity of this vascular phenotype is directly correlated to the degree of mTORC1 down regulation within the neighboring retinal ganglion cell population. CONCLUSIONS: This study establishes a cell nonautonomous role for mTORC1-signaling during retinal development. These findings contribute to our current understanding of neurovascular unit formation and demonstrate how ganglion cells actively sculpt their local environment to ensure that the retina is perfused with an appropriate supply of oxygen and nutrients.


Asunto(s)
Enfermedades de la Retina , Células Ganglionares de la Retina , Animales , Células Endoteliales/metabolismo , Mamíferos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ratones , Retina/metabolismo , Células Ganglionares de la Retina/metabolismo
3.
Cell Transplant ; 30: 963689720988245, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33522309

RESUMEN

Spinal cord injury results in irreversible tissue damage and permanent sensorimotor impairment. The development of novel therapeutic strategies that improve the life quality of affected individuals is therefore of paramount importance. Cell transplantation is a promising approach for spinal cord injury treatment and the present study assesses the efficacy of human embryonic stem cell-derived neural crest cells as preclinical cell-based therapy candidates. The differentiated neural crest cells exhibited characteristic molecular signatures and produced a range of biologically active trophic factors that stimulated in vitro neurite outgrowth of rat primary dorsal root ganglia neurons. Transplantation of the neural crest cells into both acute and chronic rat cervical spinal cord injury models promoted remodeling of descending raphespinal projections and contributed to the partial recovery of forelimb motor function. The results achieved in this proof-of-concept study demonstrates that human embryonic stem cell-derived neural crest cells warrant further investigation as cell-based therapy candidates for the treatment of spinal cord injury.


Asunto(s)
Células Madre Embrionarias Humanas/metabolismo , Cresta Neural/metabolismo , Recuperación de la Función/fisiología , Traumatismos de la Médula Espinal/terapia , Animales , Diferenciación Celular , Femenino , Humanos , Ratas , Ratas Sprague-Dawley , Traumatismos de la Médula Espinal/patología
4.
J Neurosci ; 28(3): 749-56, 2008 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-18199774

RESUMEN

The correct patterning of opsin expression in cone photoreceptors is critical for normal color vision. Thyroid hormone, and one of its receptors [thyroid hormone receptor beta2 (TRbeta2)], is an important regulator of opsin expression during cone photoreceptor development. Mice have two genes, encoding medium-wavelength (M) and short-wavelength (S) cone opsins. Targeted deletion of TRbeta2 leads to a uniform expression of S-opsin in all cone photoreceptors and a loss of M-opsin. The control of expression of TRbeta2 is therefore central to cone differentiation, yet there is little known about its regulation in the retina. We now report that the proneural bHLH (basic helix-loop-helix) transcription factor, NeuroD1, is necessary for sustained expression of TRbeta2 in immature cone photoreceptors. Mice deficient in NeuroD1 develop an opsin phenotype virtually identical with that of TRbeta2-deficient mice: all cones express S-opsin, and none expresses M-opsin. The introduction of NeuroD1 into embryonic retinal explants from NeuroD1-/- mice restores TRbeta2 expression. NeuroD1 binds an E-box in the intron control region of the TRbeta2 gene that mediates cone-specific expression, suggesting that NeuroD1 is a critical contributory factor to the expression of TRbeta2 in cones. These results thus connect the proneural pathway with opsin selection to ensure correct cone patterning during retinal development.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/fisiología , Regulación del Desarrollo de la Expresión Génica/fisiología , Retina/embriología , Retina/metabolismo , Opsinas de Bastones/metabolismo , Receptores beta de Hormona Tiroidea/metabolismo , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/deficiencia , Bromodesoxiuridina/metabolismo , Inmunoprecipitación de Cromatina/métodos , Ensayo de Cambio de Movilidad Electroforética/métodos , Embrión de Mamíferos , Regulación del Desarrollo de la Expresión Génica/genética , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Técnicas In Vitro , Ratones , Ratones Noqueados , Opsinas de Bastones/genética , Receptores beta de Hormona Tiroidea/genética , Transfección/métodos , Tubulina (Proteína)/metabolismo
5.
Biol Open ; 8(8)2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31285269

RESUMEN

Development of the vertebrate central nervous system involves the co-ordinated differentiation of progenitor cells and the establishment of functional neural networks. This neurogenic process is driven by both intracellular and extracellular cues that converge on the mammalian target of rapamycin complex 1 (mTORC1). Here we demonstrate that mTORC1-signalling mediates multi-faceted roles during central nervous system development using the mouse retina as a model system. Downregulation of mTORC1-signalling in retinal progenitor cells by conditional ablation of Rptor leads to proliferation deficits and an over-production of retinal ganglion cells during embryonic development. In contrast, reduced mTORC1-signalling in postnatal animals leads to temporal deviations in programmed cell death and the consequent production of asymmetric retinal ganglion cell mosaics and associated loss of axonal termination topographies in the dorsal lateral geniculate nucleus of adult mice. In combination these developmental defects induce visually mediated behavioural deficits. These collective observations demonstrate that mTORC1-signalling mediates critical roles during visual pathway development and function.

6.
Mol Genet Metab ; 95(3): 152-62, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18815062

RESUMEN

Herein we describe detailed characterization of four common mutations (L302P, H421Y, R496L and DeltaR608) within the acid sphingomyelinase (ASM) gene causing types A and B Niemann-Pick disease (NPD). In vitro and in situ enzyme assays revealed marked deficiencies of ASM activity in NPD cell lines homoallelic for each mutation, although Western blotting and fluorescent microscopy showed that the mutant ASM polypeptides were expressed at normal levels and trafficked to lysosomes. Co-immunoprecipitation of the polypeptides with the ER chaperone, BiP, confirmed these findings, as did in vitro expression of the mutant cDNAs in reticulocyte lysates. We further developed a computer assisted, three-dimensional model of human ASM based on homologies to known proteins, and used this model to map each NPD mutation in relation to putative substrate binding, hydrolysis and zinc-binding domains. Lastly, we generated transgenic mice expressing the R496L and DeltaR608 mutations on the complete ASM knock-out background (ASMKO), and established breeding colonies for the future evaluation of enzyme enhancement therapies. Analysis of these mice demonstrated that the mutant ASM transgenes were expressed at high levels in the brain, and in the case of the DeltaR608 mutation, produced residual ASM activity that was significantly above the ASMKO background.


Asunto(s)
Mutación , Enfermedades de Niemann-Pick/enzimología , Enfermedades de Niemann-Pick/genética , Esfingomielina Fosfodiesterasa/genética , Secuencia de Aminoácidos , Animales , Encéfalo/enzimología , Línea Celular , Células Cultivadas , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Modelos Moleculares , Datos de Secuencia Molecular , Estructura Terciaria de Proteína , Transporte de Proteínas , Alineación de Secuencia , Esfingomielina Fosfodiesterasa/química , Esfingomielina Fosfodiesterasa/metabolismo
7.
Mol Endocrinol ; 21(5): 1108-19, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17341594

RESUMEN

The Thrb gene, encoding thyroid hormone receptor beta (TRbeta), serves key roles in endocrine regulation and the development of the senses of hearing and color vision. The versatile functions of this gene depend upon its expression of distinct receptor isoforms by differential promoter activation. The TRbeta2 isoform has a particularly specialized distribution including in the anterior pituitary and cochlea. TRbeta2 is also found in immature cone photoreceptors where it has a unique role in programming the expression pattern of opsin photopigments that mediate color vision. Given the importance of precise, tissue-specific expression for the function of TRbeta2, we investigated the genomic control elements that direct this expression in vivo using lacZ reporter transgenes in mice. The TRbeta2 promoter region is sufficient for cochlear expression, whereas a complex intron control region is necessary for pituitary and retinal expression. In the retina, the intron region directs peak expression in the embryo in postmitotic, immature cones. The retinal control region is further subdivided into domains that specify and amplify expression, respectively, indicating that timely, cone-specific expression reflects an integrated response to complex signals. The mammalian Thrb gene has therefore incorporated several mechanisms into a multifunctional intron control region that regulates developmental induction of the distant promoter. This specialized genomic organization underlies the unique expression pattern and functions of TRbeta2.


Asunto(s)
Cóclea/fisiología , Regulación de la Expresión Génica , Intrones , Células Fotorreceptoras/fisiología , Hipófisis/fisiología , Receptores beta de Hormona Tiroidea/genética , Animales , Secuencia de Bases , Genes Reporteros , Ratones , Ratones Transgénicos , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , TATA Box
8.
Sci Rep ; 8(1): 15961, 2018 10 29.
Artículo en Inglés | MEDLINE | ID: mdl-30374154

RESUMEN

The ability to discriminate between diverse types of sensation is mediated by heterogeneous populations of peripheral sensory neurons. Human peripheral sensory neurons are inaccessible for research and efforts to study their development and disease have been hampered by the availability of relevant model systems. The in vitro differentiation of peripheral sensory neurons from human embryonic stem cells therefore provides an attractive alternative since an unlimited source of biological material can be generated for studies that specifically address development and injury. The work presented in this study describes the derivation of peripheral sensory neurons from human embryonic stem cells using small molecule inhibitors. The differentiated neurons express canonical- and modality-specific peripheral sensory neuron markers with subsets exhibiting functional properties of human nociceptive neurons that include tetrodotoxin-resistant sodium currents and repetitive action potentials. Moreover, the derived cells associate with human donor Schwann cells and can be used as a model system to investigate the molecular mechanisms underlying neuronal death following peripheral nerve injury. The quick and efficient derivation of genetically diverse peripheral sensory neurons from human embryonic stem cells offers unlimited access to these specialised cell types and provides an invaluable in vitro model system for future studies.


Asunto(s)
Modelos Biológicos , Traumatismos de los Nervios Periféricos/patología , Células Receptoras Sensoriales/metabolismo , Potenciales de Acción/efectos de los fármacos , Diferenciación Celular , Técnicas de Cocultivo , Células Madre Embrionarias Humanas , Humanos , Nociceptores/citología , Nociceptores/efectos de los fármacos , Nociceptores/metabolismo , Traumatismos de los Nervios Periféricos/metabolismo , Receptor de Factor de Crecimiento Nervioso/genética , Receptor de Factor de Crecimiento Nervioso/metabolismo , Receptor trkA/metabolismo , Células de Schwann/citología , Células de Schwann/metabolismo , Células Receptoras Sensoriales/citología , Células Receptoras Sensoriales/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/farmacología
9.
J Tissue Eng Regen Med ; 12(4): e2099-e2109, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29327452

RESUMEN

Surgical intervention is the current gold standard treatment following peripheral nerve injury. However, this approach has limitations, and full recovery of both motor and sensory modalities often remains incomplete. The development of artificial nerve grafts that either complement or replace current surgical procedures is therefore of paramount importance. An essential component of artificial grafts is biodegradable conduits and transplanted cells that provide trophic support during the regenerative process. Neural crest cells are promising support cell candidates because they are the parent population to many peripheral nervous system lineages. In this study, neural crest cells were differentiated from human embryonic stem cells. The differentiated cells exhibited typical stellate morphology and protein expression signatures that were comparable with native neural crest. Conditioned media harvested from the differentiated cells contained a range of biologically active trophic factors and was able to stimulate in vitro neurite outgrowth. Differentiated neural crest cells were seeded into a biodegradable nerve conduit, and their regeneration potential was assessed in a rat sciatic nerve injury model. A robust regeneration front was observed across the entire width of the conduit seeded with the differentiated neural crest cells. Moreover, the up-regulation of several regeneration-related genes was observed within the dorsal root ganglion and spinal cord segments harvested from transplanted animals. Our results demonstrate that the differentiated neural crest cells are biologically active and provide trophic support to stimulate peripheral nerve regeneration. Differentiated neural crest cells are therefore promising supporting cell candidates to aid in peripheral nerve repair.


Asunto(s)
Células Madre Embrionarias Humanas/metabolismo , Regeneración Nerviosa , Cresta Neural , Traumatismos de los Nervios Periféricos/terapia , Nervio Ciático , Animales , Línea Celular Tumoral , Femenino , Xenoinjertos , Humanos , Cresta Neural/metabolismo , Cresta Neural/trasplante , Ratas , Ratas Sprague-Dawley , Nervio Ciático/lesiones , Nervio Ciático/fisiología
10.
Eur J Obstet Gynecol Reprod Biol ; 132(2): 204-8, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17011694

RESUMEN

OBJECTIVE: To ascertain if serum concentrations following injection of human chorionic gonadotropin (hCG) influenced the outcome of in vitro fertilisation (IVF) treatment and correlated to body mass index (BMI). STUDY DESIGN: A prospective study conducted with the participation of 149 women undergoing IVF and/or intracytoplasmic sperm injection (ICSI) treatment at the regional IVF Unit in Liverpool, UK. The BMI of each individual was calculated and serum hCG concentrations were measured at 12 and 36 h following a subcutaneously (SC) injection of 5000 IU hCG. The main outcome measures were fertilisation rate and biochemical pregnancy rate. RESULTS: No correlation was found between serum hCG levels at 12 and 36 h with the number of oocytes retrieved or the number of oocytes fertilised. Furthermore, there was no correlation between BMI and hCG levels at 12 and 36 h following administration (Pearson's correlation coefficient: -0.23, -0.24, respectively). CONCLUSION: Our results suggest that the serum concentrations of hCG do not influence IVF outcome and that the serum levels of hCG achieved following administration do not correlate with the individual's BMI. Serum hCG concentration also does not correlate with number of oocytes collected or fertilisation rate.


Asunto(s)
Índice de Masa Corporal , Gonadotropina Coriónica/sangre , Gonadotropina Coriónica/farmacocinética , Fertilización In Vitro , Adulto , Buserelina/uso terapéutico , Femenino , Fármacos para la Fertilidad Femenina/uso terapéutico , Humanos , Inducción de la Ovulación/métodos , Embarazo , Resultado del Embarazo , Estudios Prospectivos , Resultado del Tratamiento
11.
Dis Model Mech ; 10(3): 245-257, 2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-28250050

RESUMEN

Development of the cornea, lens, ciliary body and iris within the anterior segment of the eye involves coordinated interaction between cells originating from the ciliary margin of the optic cup, the overlying periocular mesenchyme and the lens epithelium. Anterior segment dysgenesis (ASD) encompasses a spectrum of developmental syndromes that affect these anterior segment tissues. ASD conditions arise as a result of dominantly inherited genetic mutations and result in both ocular-specific and systemic forms of dysgenesis that are best exemplified by aniridia and Axenfeld-Rieger syndrome, respectively. Extensive clinical overlap in disease presentation amongst ASD syndromes creates challenges for correct diagnosis and classification. The use of animal models has therefore proved to be a robust approach for unravelling this complex genotypic and phenotypic heterogeneity. However, despite these successes, it is clear that additional genes that underlie several ASD syndromes remain unidentified. Here, we report the characterisation of a novel mouse model of ASD. Conditional deletion of Tsc1 during eye development leads to a premature upregulation of mTORC1 activity within the ciliary margin, periocular mesenchyme and lens epithelium. This aberrant mTORC1 signalling within the ciliary margin in particular leads to a reduction in the number of cells that express Pax6, Bmp4 and Msx1 Sustained mTORC1 signalling also induces a decrease in ciliary margin progenitor cell proliferation and a consequent failure of ciliary body and iris development in postnatal animals. Our study therefore identifies Tsc1 as a novel candidate ASD gene. Furthermore, the Tsc1-ablated mouse model also provides a valuable resource for future studies concerning the molecular mechanisms underlying ASD and acts as a platform for evaluating therapeutic approaches for the treatment of visual disorders.


Asunto(s)
Cuerpo Ciliar/embriología , Anomalías del Ojo/genética , Anomalías del Ojo/patología , Eliminación de Gen , Iris/embriología , Proteínas Supresoras de Tumor/genética , Animales , Animales Recién Nacidos , Segmento Anterior del Ojo/embriología , Segmento Anterior del Ojo/patología , Linaje de la Célula , Cuerpo Ciliar/patología , Modelos Animales de Enfermedad , Integrasas/metabolismo , Iris/patología , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ratones Transgénicos , Especificidad de Órganos , Fenotipo , Transducción de Señal , Transcripción Genética , Proteína 1 del Complejo de la Esclerosis Tuberosa , Proteínas Supresoras de Tumor/metabolismo
12.
Hum Fertil (Camb) ; 9(4): 223-9, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17190668

RESUMEN

The effect of seasonality and daylight length on mammalian reproduction leading to spring births has been well established, and is known as photoperiodism. In assisted reproduction there is much greater uncertainty as to the effect of seasonality. This was a 4-year retrospective analysis of 2709 standardised cycles of IVF/ICSI. Data was analysed with regard to the 1642 cycles occurring during the months of extended daylight (Apr-Sept) and those 1067 cycles during winter months of restricted light length (Oct-Mar). The results showed that there was significant improvement in assisted conception outcomes in cycles performed in summer (lighter) months with more efficient ovarian stimulation 766iu v880iu/per oocyte retrieved (p=0.006). There was similarly a significantly improved implantation rate per embryo transferred 11.42% vs 9.35% (p=0.011) and greater clinical pregnancy rate 20% vs 15% (p=0.0033) during summer cycles. This study appears to demonstrate a significant benefit of increased daylight length on outcomes of IVF/ICSI cycles. Whilst the exact mechanism of this is unclear, it would seem probable that melatonin may have actions at multiple sites and on multiple levels of the reproductive tract, and may exert a more profound effect on outcomes of assisted conception cycles than has been previously considered.


Asunto(s)
Fertilización In Vitro , Fertilización/fisiología , Fertilización/efectos de la radiación , Fotoperiodo , Estaciones del Año , Adulto , Femenino , Humanos , Resultado del Tratamiento
13.
Asian J Androl ; 7(2): 121-6, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15897967

RESUMEN

AIM: To investigate the impact of abnormal sperm morphology using the sperm deformity index (SDI) on reactive oxygen species (ROS) production and its correlation with sperm DNA damage. METHODS: Semen samples were collected from men undergoing infertility screening (n = 7) and healthy donors (n = 6). Mature spermatozoa were isolated and incubated with 5 mmol/L beta-nicotinamide adenine dinucleotide phosphate (NADPH) for up to 24 h to induce ROS. Sperm morphology was evaluated using strict Tygerberg's criteria and the SDI. ROS levels and DNA damage were assessed using chemiluminescence and terminal deoxynucleotidyl transferase-mediated fluorescein-dUTP nick end labeling (TUNEL) assays, respectively. RESULTS: SDI values (median [interquartiles]) were higher in patients than donors (2 [1.8, 2.1] vs. 1.53 [1.52, 1.58], P = 0.008). Aliquots treated with NADPH showed higher ROS levels (1.22 [0.30, 1.87] vs. 0.39 [0.10, 0.57], P = 0.03) and higher incidence of DNA damage than those not treated (10 [4.69, 24.85] vs. 3.85 [2.58, 5.10], P = 0.008). Higher DNA damage was also seen following 24 h of incubation in patients compared to donors. SDI correlated with the percentage increase in sperm DNA damage following incubation for 24 h in samples treated with NADPH (r = 0.7, P = 0.008) and controls (r = 0.58, P = 0.04). CONCLUSION: SDI may be a useful tool in identifying potential infertile males with abnormal prevalence of oxidative stress (OS)-induced DNA damage. NADPH plays a role in ROS-mediated sperm DNA damage, which appears to be more evident in infertile patients with semen samples containing a high incidence of morphologically abnormal spermatozoa.


Asunto(s)
Daño del ADN , Infertilidad Masculina/patología , Estrés Oxidativo , Espermatozoides/anomalías , Humanos , Infertilidad Masculina/genética , Masculino , Especies Reactivas de Oxígeno
14.
Dis Model Mech ; 8(12): 1517-29, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26449264

RESUMEN

Tuberous sclerosis complex (TSC) is an autosomal dominant syndrome that is best characterised by neurodevelopmental deficits and the presence of benign tumours (called hamartomas) in affected organs. This multi-organ disorder results from inactivating point mutations in either the TSC1 or the TSC2 genes and consequent activation of the canonical mammalian target of rapamycin complex 1 signalling (mTORC1) pathway. Because lesions to the eye are central to TSC diagnosis, we report here the generation and characterisation of the first eye-specific TSC mouse model. We demonstrate that conditional ablation of Tsc1 in eye-committed progenitor cells leads to the accelerated differentiation and subsequent ectopic radial migration of retinal ganglion cells. This results in an increase in retinal ganglion cell apoptosis and consequent regionalised axonal loss within the optic nerve and topographical changes to the contra- and ipsilateral input within the dorsal lateral geniculate nucleus. Eyes from adult mice exhibit aberrant retinal architecture and display all the classic neuropathological hallmarks of TSC, including an increase in organ and cell size, ring heterotopias, hamartomas with retinal detachment, and lamination defects. Our results provide the first major insight into the molecular etiology of TSC within the developing eye and demonstrate a pivotal role for Tsc1 in regulating various aspects of visual-pathway development. Our novel mouse model therefore provides a valuable resource for future studies concerning the molecular mechanisms underlying TSC and also as a platform to evaluate new therapeutic approaches for the treatment of this multi-organ disorder.


Asunto(s)
Ojo/patología , Eliminación de Gen , Esclerosis Tuberosa/patología , Proteínas Supresoras de Tumor/metabolismo , Vías Visuales/crecimiento & desarrollo , Vías Visuales/metabolismo , Animales , Recuento de Células , Diferenciación Celular , Movimiento Celular , Núcleo Celular/patología , Modelos Animales de Enfermedad , Gliosis/patología , Hamartoma/patología , Interneuronas/metabolismo , Ratones Noqueados , Mosaicismo , Neuritas/metabolismo , Nervio Óptico/patología , Especificidad de Órganos , Células Ganglionares de la Retina/patología , Proteína 1 del Complejo de la Esclerosis Tuberosa , Vías Visuales/patología
15.
Fertil Steril ; 79(1): 212-5, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12524092

RESUMEN

OBJECTIVE: To describe the association between specific sperm morphologic abnormalities and sperm chromosomal abnormalities on multicolor interphase fluorescence in situ hybridization (FISH). DESIGN: Case report. Reproductive medicine unit in a tertiary referral center. PATIENT(S): Three infertile men with severe oligoasthenospermia and total teratozoospermia who were referred for IVF treatment. MAIN OUTCOME MEASURE(S): Incidence of spermatozoal chromosomal aneuploidy for chromosome 18 and the sex chromosomes by using FISH. RESULT(S): Morphologic assessment of sperm revealed a high incidence of double heads, multinucleated sperm heads, and multiple tails. Hormone profiles and karyotyping of peripheral lymphocytes were normal in the three men. The proportion of sperm with disomy, trisomy and tetrasomy for chromosome 18, and the sex chromosomes in each patient was 100%, 76%, and 82.5%, respectively. CONCLUSION(S): Specific morphologic abnormalities of sperm may be associated with higher incidence of chromosomal abnormalities. Resolving infertility by offering patients in vitro fertilization/intracytoplasmic sperm injection must be approached with caution because of the significant risk for embryonic aneuploidy and chromosomal abnormalities in any subsequent offspring.


Asunto(s)
Aberraciones Cromosómicas , Infertilidad Masculina/genética , Espermatozoides/anomalías , Espermatozoides/ultraestructura , Adulto , Núcleo Celular , Cromosomas Humanos Par 18 , Cromosomas Humanos X , Cromosomas Humanos Y , Femenino , Fertilización In Vitro , Humanos , Hibridación Fluorescente in Situ , Masculino , Aberraciones Cromosómicas Sexuales , Cabeza del Espermatozoide , Cola del Espermatozoide
16.
Fertil Steril ; 80(3): 502-7, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12969689

RESUMEN

OBJECTIVE: To study the endometrial expression of three integrins (alpha v beta 3, alpha 4 beta 1, and alpha 1 beta 1) in women undergoing IVF-intracytoplasmic sperm injection (ICSI) treatment and assess whether they could be used to predict subsequent treatment success.Prospective observational study. Healthy volunteers in a large teaching hospital. PATIENT(S): Sixty-six patients attending for IVF-ICSI treatment. INTERVENTION(S): Timed endometrial biopsies were taken, during the implantation window at LH + 7-9 days, from women before IVF-ICSI treatment. MAIN OUTCOME MEASURE(S): Histological dating of endometrium and immunohistochemical staining intensity of alpha 4 beta 1, alpha v beta 3, and alpha 1 beta 1 integrins. The integrin levels were correlated with subsequent success rates. RESULT(S): There was a statistically significantly greater expression of alpha v beta 3 in the luminal epithelium of those patients who had successful treatment. However, treatment was successful in some patients with negative expression. CONCLUSION(S): Integrins are important markers of endometrial receptivity. There is an association between an in-phase endometrial biopsy, with positive luminal alpha v beta 3 integrin expression, and subsequent treatment success. However, the clinical value of assessing the endometrium before treatment has drawbacks, and further work needs to be done before this can be considered a clinically useful test.


Asunto(s)
Endometrio/metabolismo , Fertilización In Vitro , Integrina alfa1beta1/metabolismo , Integrina alfa4beta1/metabolismo , Integrinas/metabolismo , Receptores de Vitronectina/metabolismo , Adulto , Femenino , Humanos , Inmunohistoquímica , Estudios Prospectivos , Inyecciones de Esperma Intracitoplasmáticas , Resultado del Tratamiento
17.
Fertil Steril ; 82(3): 621-7, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15374705

RESUMEN

OBJECTIVE: To examine the relationship between leukocyte concentrations in semen and sperm morphology in a group of infertile men and healthy fertile donors. DESIGN: A prospective clinical study. SETTING: Male infertility clinic at a tertiary care teaching hospital and a reproductive medicine unit at a Women's Hospital in the United Kingdom. PATIENT(S): Fifty-six infertile men and 13 healthy fertile sperm donors (control). INTERVENTION(S): Standard semen analysis, seminal leukocyte concentration, and the assessment of sperm morphology and sperm deformity index (SDI), applying Tygerberg's strict criteria. MAIN OUTCOME MEASURE(S): Granulocyte concentrations in semen, percentages of different sperm morphological abnormalities, and SDI scores. RESULT(S): Leukocyte concentrations were statistically significantly and negatively correlated with the proportion of sperm with damaged acrosomes, cytoplasmic droplet, tail defects, and SDI scores with normal and borderline morphology. The percentage sperm motility was significantly and negatively correlated with leukocytic concentration in semen. However, the leukocytic concentration was not significantly correlated with sperm concentration. CONCLUSION(S): This is the first study to report a significant positive correlation between leukocytospermia and sperm tail defects, acrosomal damage, and high SDI scores. These observations suggest that leukocytospermia is associated with compromised sperm structural integrity.


Asunto(s)
Infertilidad Masculina/etiología , Leucocitosis/patología , Espermatozoides/anomalías , Acrosoma/patología , Humanos , Infertilidad Masculina/sangre , Infertilidad Masculina/patología , Recuento de Leucocitos , Leucocitosis/sangre , Masculino , Semen/citología , Motilidad Espermática , Cola del Espermatozoide/patología , Espermatozoides/patología , Espermatozoides/fisiología
18.
Fertil Steril ; 77(6): 1162-6, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12057722

RESUMEN

OBJECTIVE: To determine if the cryopreservation of epididymal and testicular spermatozoa alters their reproductive potential by examination of patients who underwent consecutive cycles of ICSI using fresh and then cryopreserved spermatozoa. DESIGN: Retrospective review. SETTING: Tertiary care university hospital. PATIENT(S): One hundred sixty-two consecutive cycles of ICSI were analyzed. Thirteen patients were identified as having undergone treatment with freshly retrieved epididymal spermatozoa; these patients subsequently underwent treatment with spermatozoa cryopreserved from that cycle. Eighteen patients underwent ICSI with freshly retrieved testicular spermatozoa; these patients subsequently underwent treatment with spermatozoa cryopreserved from that cycle. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Fertilization rates and pregnancy rates. RESULT(S): The fertilizing capacity of epididymal spermatozoa remained unchanged after cryopreservation and subsequent thawing, with fertilization rates of 58% and 57% for fresh and cryopreserved spermatozoa, respectively. Testicular spermatozoa, however, showed a significant decrease in fertilizing capacity after cryopreservation when compared with freshly retrieved spermatozoa (52% and 71%, respectively). Pregnancy rates appeared unaffected by the cryopreservation of epididymal spermatozoa (fresh, 3/13; frozen, 2/13) or testicular spermatozoa (fresh, 2/18; frozen, 5/18). CONCLUSION(S): This study offers further evidence that motile epididymal spermatozoa retain their fertilizing capacity after cryopreservation. The data presented on testicular spermatozoa suggest that although cryopreservation may reduce the fertilizing capacity of testicular spermatozoa, there is no decrease in pregnancy rates.


Asunto(s)
Criopreservación , Fertilización , Inyecciones de Esperma Intracitoplasmáticas , Espermatozoides/fisiología , Adulto , Epidídimo , Femenino , Humanos , Masculino , Metafase , Persona de Mediana Edad , Oocitos/fisiología , Embarazo , Índice de Embarazo , Estudios Retrospectivos , Testículo
19.
Fertil Steril ; 79(1): 56-62, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12524064

RESUMEN

OBJECTIVE: To determine patients' experiences with surgical sperm retrieval and its common complications. DESIGN: A questionnaire based survey using visual analogue scales (VAS) and closed questions to analyze complication, pain, and satisfaction rates. SETTING: Tertiary care university hospital. PATIENT(S): One hundred consecutive males undergoing surgical sperm retrieval by percutaneous epididymal sperm aspiration (PESA) or testicular sperm extraction (TESE). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): We surveyed for pain perception complication rates and satisfaction scores. RESULT(S): Of the 85 patients who replied, 21 underwent retrieval for nonobstructive causes, 37 following failed reversal of vasectomy, and 27 for other obstructive causes. Retrieval was successful in 100% of obstructive causes and in 61% for nonobstructive azoospermia. Epididymal retrieval was successful in 23 patients, 30 patients underwent TESE after failed PESA, and 23 had TESE only. There were significant increases in pain perception scores and reported complications with TESE over PESA (31 vs. 16; and 21 out of 63 vs. 2 out of 22, respectively), but no difference in satisfaction rate. The cause of azoospermia did not affect pain perception or satisfaction in TESE. Complication rates were increased in larger testes (3 out of 22 vs. 24 out of 63). Unsuccessful sperm retrieval did not significantly affect patients' pain perception or satisfaction. Surgical sperm retrieval was rated as significantly less painful than both vasectomy and reversal (21% vs. 42% vs. 57%, respectively) and was associated with significantly fewer days absent from work (3.0 vs. 8.5). CONCLUSION(S): Surgical sperm retrieval by PESA or TESE is a safe procedure with only minor complications that is tolerated well by patients.


Asunto(s)
Dolor , Satisfacción del Paciente , Complicaciones Posoperatorias , Espermatozoides , Recolección de Tejidos y Órganos/métodos , Adulto , Epidídimo/citología , Femenino , Humanos , Masculino , Oligospermia/terapia , Embarazo , Inyecciones de Esperma Intracitoplasmáticas , Succión , Encuestas y Cuestionarios , Testículo/citología , Recolección de Tejidos y Órganos/efectos adversos , Vasectomía , Vasovasostomía
20.
Fertil Steril ; 81(2): 349-54, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14967372

RESUMEN

OBJECTIVE: To examine the relationship between sperm reactive oxygen species (ROS) production and sperm morphology in a group of infertile men and healthy fertile donors. DESIGN: A prospective clinical study. SETTING: Male infertility clinic, Glickman Urological Institute, The Cleveland Clinic Foundation, Cleveland, Ohio, and the Reproductive Medicine Unit, Liverpool Women's Hospital, United Kingdom PATIENT(S): Thirty-nine infertile men and 13 healthy fertile donors (control). INTERVENTION(S): Standard semen analysis, seminal leukocyte concentration, assessment of sperm morphology, and measurement of sperm ROS production. MAIN OUTCOME MEASURE(S): Levels of sperm ROS production, percentages of different sperm morphological abnormalities, and the sperm deformity index (SDI) scores. RESULT(S): A significant negative correlation was observed between sperm ROS production and the proportion of sperm with normal morphology and borderline morphology. Reactive oxygen species production was positively correlated with the proportion of sperm with amorphous heads, damaged acrosomes, midpiece defects, cytoplasmic droplets, tail defects, and SDI scores. Logistic regression analysis identified a two-variable model including SDI and percentage sperm motility, which correctly identified 84% of individuals with high seminal ROS and 85% of individuals with low seminal ROS. The model had an overall accuracy of 85%. CONCLUSION(S): The standard semen analysis to assess sperm motility, sperm morphology, and the SDI scores is a useful tool in identifying infertile men with high seminal ROS in infertility clinics where facilities for measuring levels of seminal ROS are not available.


Asunto(s)
Especies Reactivas de Oxígeno/efectos adversos , Espermatozoides/anomalías , Espermatozoides/fisiología , Femenino , Humanos , Infertilidad/fisiopatología , Infertilidad Masculina/fisiopatología , Leucocitos/citología , Masculino , Peroxidasa/análisis , Embarazo , Estudios Prospectivos , Valores de Referencia , Semen/citología , Motilidad Espermática , Espermatozoides/patología
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