Altered brain function and structure pre- and post- COVID-19 infection: a longitudinal study

BACKGROUND

Evidence indicates that the SARS-CoV-2 virus can infect the brain, resulting in central nervous system symptoms. However, there is a lack of a longitudinal imaging study investigating the impact of Coronavirus disease 2019 (COVID-19) infection on brain function. Consequently, this study aimed to fill this knowledge gap using functional magnetic resonance imaging (fMRI).

METHODS

Twenty-one participants underwent two resting-state fMRI scans before and after infection. The amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) were assessed to identify the brain function changes. Additionally, voxel-based morphometry (VBM) was utilized to assess changes in brain structure. Subsequently, brain regions that showed significant differences were identified as regions of interest (ROI) in functional connectivity analysis (FC).

RESULTS

After infection, ALFF was increased in the bilateral paracentral lobe and postcentral gyrus while decreased in the bilateral precuneus. Moreover, ReHo was decreased in the cerebellar vermis, accompanied by a decrease in FC with the bilateral postcentral gyrus. Furthermore, gray matter volume (GMV) reduction was observed in the left thalamus. The results of the correlation analysis revealed a negative correlation between ALFF values in the bilateral precuneus and scores on the self-rating anxiety scale (SAS) in pre- and post-infection datasets.

CONCLUSION

Neuroimaging alterations may occur before the manifestation of clinical symptoms, indicating that the functioning of the motor and sensory systems, as well as their connection, might be affected following infection. This alteration can potentially increase the potential of maladaptive responses to environmental stimuli. Furthermore, patients may be susceptible to future emotional disorders.

Exploring the therapeutic mechanisms of Sijunzi decoction in the treatment of sarcopenia: Key targets and signaling pathways

Sarcopenia, an age-associated condition, negatively impacts the quality of life. This study investigates the mechanism of Sijunzi decoction (SJZD), a traditional Chinese formula, against sarcopenia. Active compounds and potential targets of SJZD for sarcopenia were gathered from databases. Hub targets were identified using protein-protein interaction networks, with GO and KEGG analyses suggesting potential pathways. Molecular docking was used to assess compound-target affinity. A lipopolysaccharide-induced sarcopenia rat model was used to verify the targets. Sijunzi decoction contains 92 compounds and 47 targets for sarcopenia. The top 10 hub targets comprise AKT1, ALB, INS, IL6, TNF, TP53, VEGFA, SIRT1, CAT and FOS. GO and KEGG analyses indicate involvement in steroid hormone response, vesicle lumen, receptor agonist activity, and FoxO and HIF-1 signaling pathways. Validation experiments showed that SJZD alleviates sarcopenia by downregulating SIRT1, IL-6, TNF and AKT1. Sijunzi decoction treats sarcopenia by targeting SIRT1, IL-6, TNF and AKT1, potentially involving FoxO and HIF-1 signaling pathways. This highlights SJZD's potential for sarcopenia treatment.