Question

Alzheimer's disease (AD) is the most common neurodegenerative disease in which a particular set of neurons undergoes apoptotic cell death. Identify a signaling pathway that may attenuate neuronal apoptosis in patients with AD. a. JNK signaling b. p38 MAP kinase signaling c. bcl 2 signaling d. Rho kinase signaling e. Ceramide signaling

Short answer

Answer: c. bcl 2 signaling

Step-by-step solution

JNK signaling

JNK (c-Jun N-terminal kinase) signaling is a stress-activated protein kinase, involved in multiple cellular functions, including cell differentiation, cell survival, and apoptosis. In Alzheimer's disease, JNK activation is typically associated with increased neuronal death.

p38 MAP kinase signaling

p38 MAP kinase signaling is also a stress-activated kinase, primarily involved in inflammation and cell-cycle regulation. However, it has also been implicated in promoting cell death in neurodegenerative diseases, including Alzheimer's.

bcl 2 signaling

The bcl 2 (B-cell lymphoma 2) family proteins are central regulators of apoptosis. They include both pro-apoptotic (cell death-promoting) and anti-apoptotic (cell survival-promoting) proteins. In neuronal cells, the upregulation of anti-apoptotic bcl 2 proteins leads to reduced apoptosis and increased cell survival.

Rho kinase signaling

Rho kinase signaling is involved in various cellular processes, including actin cytoskeleton organization, cell adhesion, and cell migration. However, excessive Rho kinase activation has been associated with neuronal apoptosis in neurodegenerative diseases.

Ceramide signaling

Ceramides are lipid signaling molecules that have been implicated in various cellular processes, including cell growth, cell differentiation, and cell death. Increased ceramide levels have been reported in the brains of Alzheimer's disease patients and are thought to contribute to neuronal apoptosis.

Identify the signaling pathway

From the brief descriptions of the given signaling pathways, it becomes evident that the bcl 2 signaling pathway is the one associated with reducing neuronal apoptosis and promoting cell survival. The other signaling pathways are more likely to contribute to or promote apoptosis in neurodegenerative diseases. Thus, the correct answer is: c. bcl 2 signaling