Hydrogen peroxide-induced Ca2+ responses in CNS pericytes

Area of Science:

• Neuroscience
• Cell Biology
• Biochemistry

Background:

• Central nervous system (CNS) pericytes play crucial roles in regulating neurovascular function.
• Reactive oxygen species (ROS) are implicated in various physiological and pathological processes within the CNS.
• The interplay between ROS and intracellular calcium (Ca2+) signaling in CNS pericytes remains incompletely understood.

Purpose of the Study:

• To investigate the interaction between reactive oxygen species (ROS) and Ca2+ signaling in cultured CNS pericytes.
• To determine the source of Ca2+ influx in response to hydrogen peroxide (H2O2) in CNS pericytes.
• To explore the potential role of tyrosine kinases in mediating H2O2-induced Ca2+ responses.

Main Methods:

• Cultured CNS pericytes were utilized for experimental analysis.
• Intracellular Ca2+ concentrations were measured using the fluorescent indicator fura-2.
• Various agents were employed, including hydrogen peroxide, catalase, nicardipine, thapsigargin, genistein, and tyrphostin A47.

Main Results:

• Hydrogen peroxide induced a dose-dependent increase in cytosolic Ca2+, which was fully inhibited by catalase.
• The Ca2+ response to H2O2 was largely independent of external Ca2+ and unaffected by depletion of intracellular Ca2+ stores.
• Pretreatment with tyrosine kinase inhibitors (genistein, tyrphostin A47) significantly attenuated the H2O2-evoked Ca2+ increase.

Conclusions:

• Hydrogen peroxide stimulates Ca2+ release predominantly from intracellular stores in CNS pericytes.
• This intracellular Ca2+ mobilization appears to be modulated by tyrosine kinase signaling pathways.
• The findings shed light on the mechanisms of ROS-induced Ca2+ signaling in CNS pericytes, relevant to neurovascular regulation.