Mitochondria transmit signals in the immune system and nervous system

Protects against bacteria and viruses

Certain cytokines and intracellular pathogens, such as viruses and some bacteria, activate the transcription factor NF-κB, which regulates the expression
of various genes.
Konstanze Winklhofer explains: "Depending on the stimulus and cell type, NF-κB activation prevents cell death and increases the protein synthesis
needed to eliminate bacteria or viruses.
" However, once activated excessively and for a long time, this basic protective pathway can lead to chronic inflammation
.
"Therefore, fine-tuning these signaling processes is medically important to prevent pathophysiological conditions
caused by insufficient or excessive NF-κB activation.
"

Mitochondria have two advantages: one is mobile, and the other is large surface area

New research shows that mitochondria play a crucial role
in regulating the NF-κB signaling pathway.
Within minutes of pathway activation, the signaling platform assembles the outer mitochondrial membrane, resulting in NF-κB activation
.
Konstanze Winklhofer said: "This allows signal amplification, based on the large surface
of mitochondria.
" "In addition, mitochondria have the ability to make them organelles for signal transduction: they are mobile and can dock on
motor proteins in cells.
" The team observed that mitochondria escort activated transcription factor NF-κB to the nuclear membrane, thereby facilitating the translocation
of NF-κB into the nucleus.

However, mitochondria are not only involved in the efficient activation of the NF-κB signaling pathway; They also help with inactivation, thereby modulating the signal
.
This is done by an enzyme located in the outer mitochondrial membrane, which counteracts ubiquitination, a post-translational modification
required for NF-κB activation.

Why people with Parkinson's disease are more susceptible to certain infections

Two genes associated with Parkinson's disease are involved in mitochondrial regulation of the NF-κB signaling pathway: PINK1 and Parkin
.
Konstanze Winklhofer noted: "Our findings explain why mutations that cause loss of function in PINK1 or Parkin promote neuronal cell death
under stress conditions.
" "Notably, our findings suggest that Parkinson's disease patients with mutations in the PINK1 or Parkin genes have increased
vulnerability to various infections caused by intracellular pathogens.
" Therefore, our research also contributes to a better understanding of the interface between the nervous system and the
immune system.
”