Video Experimental Relacionado
Updated: May 5, 2026
13:21
In Vivo Biosensor Tracks Non-apoptotic Caspase Activity in Drosophila
Published on: November 27, 2016
8.6K
Requisito diferencial para la caspasa 9 en las vías apoptóticas in vivo
1Amgen Institute, Toronto, Ontario, Canada.
Cell
|August 26, 1998
Resumen
Las mutaciones de Caspase 9 (Casp9) causan letalidad embrionaria y deterioro del desarrollo cerebral al bloquear la apoptosis. Los estudios revelan que Casp9 actúa aguas abajo del citocromo c, destacando al menos cuatro vías distintas de apoptosis celular en mamíferos.
Área de la Ciencia:
- Biología celular Biología celular.
- Biología del desarrollo Biología del desarrollo.
- Biología Molecular Biología Molecular
Sus antecedentes:
- La caspasa 9 (Casp9) es crucial para la apoptosis, un proceso de muerte celular programada.
- La deficiencia de Casp9 conduce a la letalidad embrionaria y a defectos de desarrollo, particularmente en el cerebro.
- Comprender el papel de Casp9 es vital para descifrar las vías apoptóticas y su impacto en el desarrollo.
Objetivo del estudio:
- Para investigar el papel preciso de la caspasa 9 en varios estímulos apoptóticos.
- Determinar la posición de Casp9 dentro de la cascada apoptótica, específicamente en relación con el citocromo c.
- Para dilucidar la diversidad de las vías apoptóticas en las células de mamíferos.
Principales métodos:
- Utilizado Caspase 9 knockout (Casp9-/-) células madre embrionarias, fibroblastos y timocitos.
- Las células mutantes expuestas a varios inductores apoptóticos como la irradiación UV, la irradiación gamma, la dexametasona y el anticuerpo anti-CD95.
- Se evaluó la resistencia a la apoptosis, el potencial de la membrana mitocondrial, la liberación del citocromo c y el procesamiento de la caspasa.
Principales resultados:
- Las células Casp9-/- exhibieron resistencia a los rayos UV, la irradiación gamma y la apoptosis inducida por la dexametasona, pero sensibilidad al anti-CD95.5.
- El potencial de la membrana mitocondrial se mantuvo en las células Casp9-/- y el citocromo c se translocó al citosol tras la estimulación UV.
- El procesamiento de la caspasa fue inhibido en las células Casp9-/-ES, lo que indica que Casp9 actúa aguas abajo del citocromo c.
- Respuestas apoptóticas distintas en diferentes tipos de células sugirieron múltiples vías.
Conclusiones:
- La caspasa 9 juega un papel crítico en múltiples vías apoptóticas, actuando aguas abajo del citocromo c.
- El estudio identificó al menos cuatro vías apoptóticas distintas en células de mamíferos basadas en los requisitos de Casp9 y Casp3.
- Estos hallazgos profundizan nuestra comprensión de la regulación de la apoptosis y sus implicaciones en el desarrollo y la enfermedad.
Videos de Conceptos Relacionados
01:30Overview of Cell Death
7.7K
Cell death is an essential process where the body gets rid of old or damaged cells. Cell proliferation and death need to be balanced, as an imbalance between the two may lead to cancer or autoimmune diseases.
Cell death was observed in the early 19th century, but there was no experimental evidence to prove it. In 1842, Carl Vogt first discovered cell death in a metamorphic toad; however, it was not termed ‘cell death.’ Scientists discovered different cell death pathways only in the...
Cell death was observed in the early 19th century, but there was no experimental evidence to prove it. In 1842, Carl Vogt first discovered cell death in a metamorphic toad; however, it was not termed ‘cell death.’ Scientists discovered different cell death pathways only in the...
7.7K
01:30Apoptosis
12.2K
Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size...
12.2K
01:24Caspases
8.7K
Caspase, a family of cysteine proteases, serve as effectors in apoptosis. The ced3 gene in C.elegans was first identified to be involved in apoptosis. This gene encodes the ced-3 caspase that is similar to the interleukin-1-beta converting enzyme or ICE in mammals. In addition to apoptosis, caspases also function in the inflammatory response. Inflammatory caspases are essential in activating pro-inflammatory cytokines that recruit immune cells and block the replication of pathogens inside...
8.7K
01:17The Extrinsic Apoptotic Pathway
6.2K
The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
6.2K
01:31The Intrinsic Apoptotic Pathway
6.2K
Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
6.2K
01:22Cellular Injury V: Apoptosis and Autophagy
121
Cells respond to damage and stress through highly coordinated processes that decide whether they survive or undergo controlled self-destruction. Two major pathways involved in this regulation are apoptosis, a type of programmed cell death, and autophagy, a survival mechanism that helps cells adapt to adverse conditions.ApoptosisApoptosis removes aged or injured cells to maintain tissue balance. During this process, the cell shrinks, chromatin condenses and fragments, and membrane-bound...
121