Related Experiment Video
Updated: Nov 17, 2025
Author Spotlight: Establishing a New Fluorescence-Based Protocol for In Vivo Mitochondrial Morphology Analysis in Parkinson's Disease
Published on: June 23, 2023
Changes in mitochondrial morphology modulate LPS-induced loss of calcium homeostasis in BV-2 microglial cells
O R Pereira1, V M Ramos1, J V Cabral-Costa2
1Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, São Paulo, SP, 05508-000, Brazil.
Abstract:
Microglial activation involves both fragmentation of the mitochondrial network and changes in cellular Ca2+ homeostasis, but possible modifications in mitochondrial calcium uptake have never been described in this context. Here we report that activated microglial BV-2 cells have impaired mitochondrial calcium uptake, including lower calcium retention capacity and calcium uptake rates. These changes were not dependent on altered expression of the mitochondrial calcium uniporter. Respiratory capacity and the inner membrane potential, key determinants of mitochondrial calcium uptake, are both decreased in activated microglial BV-2 cells. Modified mitochondrial calcium uptake correlates with impaired cellular calcium signaling, including reduced ER calcium stores, and decreased replenishment by store operated calcium entry (SOCE). Induction of mitochondrial fragmentation through Mfn2 knockdown in control cells mimicked this effect, while inhibiting LPS-induced mitochondrial fragmentation by a dominant negative form of Drp1 prevented it. Overall, our results show that mitochondrial fragmentation induced by LPS promotes altered Ca2+ homeostasis in microglial cells, a new aspect of microglial activation that could be a key feature in the inflammatory role of these cells.
Insights
Activated microglia show impaired mitochondrial calcium uptake due to fragmentation, affecting cellular calcium signaling and contributing to neuroinflammation. This study reveals a novel aspect of microglial activation.
Area of Science:
- Neuroscience
- Cell Biology
- Immunology
Background:
- Microglial activation is linked to mitochondrial fragmentation and altered cellular calcium (Ca2+) homeostasis.
- The specific impact on mitochondrial Ca2+ uptake during microglial activation remains unexplored.
Purpose of the Study:
- To investigate mitochondrial calcium uptake in activated microglial cells.
- To determine the relationship between mitochondrial fragmentation and calcium homeostasis in microglial activation.
Main Methods:
- Assessed mitochondrial calcium uptake, retention capacity, and rates in activated BV-2 microglial cells.
- Evaluated respiratory capacity, inner membrane potential, and endoplasmic reticulum (ER) calcium stores.
- Utilized Mfn2 knockdown and dominant-negative Drp1 to manipulate mitochondrial fragmentation.
Main Results:
- Activated microglial BV-2 cells exhibited impaired mitochondrial calcium uptake and reduced calcium retention capacity.
- Decreased respiratory capacity and inner membrane potential were observed in activated microglia.
- Mitochondrial fragmentation correlated with impaired cellular calcium signaling, including reduced ER calcium and store-operated calcium entry (SOCE).
- Inhibition of mitochondrial fragmentation prevented LPS-induced alterations in calcium homeostasis.
Conclusions:
- Microglial activation, induced by LPS, leads to mitochondrial fragmentation and subsequent alterations in cellular Ca2+ homeostasis.
- Impaired mitochondrial calcium uptake is a novel characteristic of activated microglia.
- These findings highlight a new mechanism linking microglial activation, mitochondrial dynamics, and neuroinflammation.
