Question

Which receptor does SDF-1 activate to induce migration of NPC? a. \(\mathrm{CCR} 2\) b. \(\mathrm{CCR} 4\) c. CXCR4 d. CX3CRl

Short answer

Answer: c. CXCR4

Step-by-step solution

Understand SDF-1 and NPC

SDF-1, also known as Stromal cell-derived factor 1 or CXCL12, is a chemokine molecule that plays a role in various biological processes, including cell migration and immune responses. NPC stands for Neural Progenitor Cells, which are precursor cells that can develop into different types of neurons and glial cells.

Identify the receptor activated by SDF-1

The receptor activated by SDF-1 to induce migration of NPC is known as CXCR4. CXCR4 is a G-protein-coupled receptor that plays a role in various cellular processes, including cell migration and immune responses.

Choose the correct answer among the options

The correct answer is the one that corresponds to CXCR4. In the given options: a. CCR2 b. CCR4 c. CXCR4 d. CX3CR1 The correct answer is option c, which is CXCR4.

Key concepts

SDF-1 (CXCL12)

SDF-1, or Stromal cell-derived factor 1, is also referred to as CXCL12. It is a chemokine, a type of signaling protein, which is essential in guiding the movement of cells. Its main role revolves around orchestrating cell migration, essentially aiding cells in moving to where they are needed in the body.

SDF-1 has broad implications in many physiological processes, including blood cell formation and tissue repair. It operates by binding to specific receptors on the surface of cells. This binding event prompts the cells to move, contributing to various processes such as immune defense and development of the nervous system.

Understanding how SDF-1 works can shed light on how our body manages cell positioning, and how malfunctions in this process can lead to diseases.

Cell Migration

Cell migration is the process that allows cells to move from one location to another. It is a critical phenomenon in numerous biological functions, such as wound healing, immune response, and embryonic development.

During cell migration, cells undergo a series of changes:

• They extend structures known as pseudopodia to probe their environment.
• Once they find the right direction, cells contract to "pull" themselves forward.

The movement is guided by changes in the cytoskeleton, a network within the cell that affords cell shape and movement.

Chemical signals, like chemokines (SDF-1 being an example), can act as cues directing cells to their appropriate location. This process is not only significant in regular body functions but also in understanding how cancer spreads, as tumor cells often exploit normal migratory mechanisms to metastasize.

CXCR4 Receptor

The CXCR4 receptor is a G-protein-coupled receptor. This type of receptor is common in transmitting signals from outside the cell to its interior, prompting specific responses.

CXCR4 is crucial in multiple cellular processes, particularly in cell migration, where it is activated by the chemokine SDF-1. When SDF-1 binds to CXCR4, it triggers cascades of signals that result in cells moving towards higher concentrations of SDF-1. This is often seen in the body's immune response, where cells need to rapidly move to sites of infection or injury.

Importantly, the CXCR4-SDF-1 axis is also implicated in cancer metastasis. Some cancer cells hijack this system to spread to other parts of the body, making CXCR4 a target for therapeutic interventions. Understanding CXCR4's role offers insights not only into developmental processes but also into devising strategies to combat diseases linked to abnormal cell migration.