[Thymosin β4 inhibits pyroptosis in BV2 microglial cells: a mechanistic study <i>in vitro</i>].
Thymosin β4 appears to reduce cell death and inflammatory markers in BV2 microglial cells subjected to pyroptosis, but its clinical relevance in humans is not established.
Where it sits
this study against the rest of the thymosin alpha-1 corpusSummary and findings
This study investigated the effects of thymosin β4 (Tβ4) on pyroptosis in BV2 microglial cells, specifically looking at cell viability and inflammatory markers. BV2 cells were treated with lipopolysaccharide and nigericin, followed by Tβ4 treatment. The results indicated a decrease in cell death and inflammatory markers with Tβ4 treatment compared to the pyroptosis group.
Abstract
<h4>Objectives</h4>To investigate the protective effects and molecular mechanisms of thymosin β4 (Tβ4) on pyroptosis in BV2 microglial cells.<h4>Methods</h4>BV2 cells were divided into three groups: control group (no treatment), pyroptosis group [stimulated with 1 μg/mL lipopolysaccharide (LPS) for 12 hours, followed by 10 μmol/L nigericin (Nig) treatment for 1 hour], and Tβ4 treatment group (co-incubated with LPS and Nig, then treated with 1 μg/mL Tβ4 for 1 hour). An <i>in vitro</i> sepsis-associated encephalopathy model was established by LPS and Nig co-treatment. Viability of BV2 cells was assessed by CCK-8 assay. RT-qPCR was performed to detect mRNA expression of interleukin (IL)-1β, interferon-induced protein with tetratricopeptide repeats 1 (IFIT1), and interferon-β (IFN-β). IL-1β levels in cell supernatants were measured by ELISA. Protein expression of NLRP3, GSDMD-N, cleaved caspase-1, phosphorylated stimulator of interferon genes (p-STING), and phosphorylated interferon regulatory factor 3 (p-IRF3) was analyzed by Western blot. Cell death rate and mitochondrial reactive oxygen species (ROS) levels were detected by flow cytometry using propidium iodide staining and MitoSOX indicator, respectively.<h4>Results</h4>Compared with the pyroptosis group, Tβ4 treatment alleviated morphological damage caused by pyroptosis in BV2 cells. Intracellular mRNA expression of IL-1β, IFIT1, and IFN-β; IL-1β concentration in supernatant; protein expression of NLRP3, GSDMD-N, cleaved caspase-1, p-STING, and p-IRF3; cell death rate; and mitochondrial ROS levels were significantly decreased (<i>P</i>0.05).<h4>Conclusions</h4>Tβ4 protects BV2 microglial cells against LPS and Nig-induced pyroptosis by inhibiting oxidative stress and inflammatory responses, potentially through regulation of the cGAS-STING signaling pathway.
Background
The study addresses the role of thymosin β4 (Tβ4) in modulating pyroptosis, a form of programmed cell death associated with inflammation, in BV2 microglial cells. Prior research has indicated that pyroptosis contributes to neuroinflammation, and Tβ4 has been suggested to have protective effects in various cellular contexts. Understanding the mechanisms by which Tβ4 may mitigate pyroptosis could provide insights into potential therapeutic strategies for neuroinflammatory conditions.
Methods
The study utilized an in vitro model with BV2 microglial cells divided into three groups: a control group, a pyroptosis group treated with 1 μg/mL lipopolysaccharide (LPS) for 12 hours followed by 10 μmol/L nigericin for 1 hour, and a Tβ4 treatment group co-incubated with LPS and nigericin before receiving 1 μg/mL Tβ4 for 1 hour. Various assays were conducted to assess cell viability, mRNA expression, protein levels, and cell death.
Results
Tβ4 treatment resulted in a significant decrease in IL-1β concentration in the supernatant, protein expression of inflammatory markers, cell death rate, and mitochondrial ROS levels compared to the pyroptosis group, with all findings reported as statistically significant (P<0.05).
Interpretation
While the results indicate that Tβ4 may have a protective effect against pyroptosis in BV2 microglial cells, the clinical significance of these findings remains uncertain. The study's in vitro nature and lack of human data limits the applicability of the results to clinical practice. Additionally, the effect sizes, while statistically significant, may not translate to meaningful clinical outcomes without further research.
Key findings
- IL-1β concentration in supernatant significantly decreased, P<0.05.
- Protein expression of NLRP3, GSDMD-N, cleaved caspase-1, p-STING, and p-IRF3 significantly decreased, P<0.05.
- Cell death rate significantly decreased, P<0.05.
- Mitochondrial ROS levels significantly decreased, P<0.05.
Limitations
- In vitro study with BV2 microglial cells only.
- No human data reported.
- Lack of long-term follow-up.
- Statistical significance does not imply clinical relevance.