Altered olfactory function in the MRL model of CNS lupus

Area of Science:

• Neuroimmunology
• Autoimmune Diseases
• Neuroscience

Background:

• Systemic lupus erythematosus (SLE) is a chronic autoimmune disease affecting multiple organs, including the central nervous system (CNS).
• CNS involvement in SLE can lead to brain atrophy and neuropsychiatric symptoms.
• Olfactory deficits have been anecdotally reported in SLE patients with CNS complications.

Purpose of the Study:

• To investigate olfactory dysfunction in MRL/lpr mice, a model for spontaneous lupus-like disease.
• To determine if autoimmune processes in SLE impact odor-guided behaviors and olfactory system neurogenesis.

Main Methods:

• Utilized a battery of odor-guided behavioral paradigms to assess olfactory function in lupus-prone MRL/lpr mice.
• Examined the distribution of Doublecortin-positive (DCX+) cells, a marker for neuronal precursor cells, in the rostral migratory stream (RMS).

Main Results:

• Lupus-prone male mice exhibited reduced exploration of unfamiliar conspecifics.
• Mice showed age-dependent deficits in discriminating low concentrations of odors.
• Olfactory changes correlated with altered DCX+ cell distribution in the RMS, indicating disrupted neurogenesis.

Conclusions:

• The findings support the hypothesis that SLE-like conditions affect periventricular brain regions, including the RMS.
• Disrupted migration of neuronal precursor cells may underlie olfactory deficits in autoimmune disease.
• Hyposmia and olfactory memory deficits could be early indicators of CNS damage in SLE.