TSH inhibits eNOS expression in HMEC-1 cells through the TSHR/PI3K/AKT signaling pathway

Expression of functional thyroid-stimulating hormone receptor in microglia

OBJECTIVE

The purpose of the present study was to clarify the expression of thyroid-stimulating hormone receptor (TSHR) in microglial cells, and to explore its function.

MATERIALS AND METHODS

Expression of TSHR in microglia was determined by Western blot, immunocytofluorescence and double immunohistofluorescence. Cyclic adenosine 3',5'-monophosphate (cAMP) production was measured after thyrotropin receptor stimulating antibody (TSAb) treatment.

RESULTS

Results showed that TSHR protein was expressed and mainly located in the mouse microglia membrane. Moreover, TSAb stimulated cAMP production in mouse microglia (p<0.05).

CONCLUSIONS

This study demonstrated the presence of TSHR in microglial cells. Brain TSHR was able to respond specifically to TSAb stimulation, suggesting that TSHR expression is functional. As microglia are innate immune cells that maintain environmental stability in the central nervous system and play a key role in many neuroimmune diseases, expression of functional TSHR in microglia has important pathophysiological implications.

Oxidative stress and radioiodine treatment of differentiated thyroid cancer

It is hypothesized that the oxidative stress level in thyroid cancer patients is additionally upregulated by radioactive iodine (RAI) treatment, that may exert an important impact on future health concerns. In our study, we evaluated the oxidative stress level changes using the measurement of malondialdehyde (MDA) concentration in patients with differentiated thyroid cancer (DTC) undergoing RAI treatment. Considering the results obtained in the study group, the serum levels of MDA in DTC patients were significantly higher compared to the healthy subjects (p < 0.05). The MDA concentration was significantly higher on the third day after RAI (p < 0.001) and significantly lower one year after RAI (p < 0.05) in DTC patients compared to the baseline concentration. Moreover, the redox stabilization after RAI treatment in patients with DTC during a year-long observation was demonstrated. Accordingly, an increased oxidative stress impact on the related biochemical parameters reflecting the health conditions of the DTC patients was determined. Our study showed that increased oxidative stress reflected by MDA measurements in DTC patients is further enhanced by RAI, but this effect is no longer observed one year after the therapy.

Long non-coding RNA NEAT1 regulates endothelial functions in subclinical hypothyroidism through miR-126/TRAF7 pathway

Subclinical hypothyroidism (SCH) is associated with increased risks of endothelial dysfunction and atherosclerosis, but the mechanisms remain unclear. In our previous study, microRNA-126-3p was downregulated in SCH, but the role and regulatory mechanism of miR-126 in SCH has not been investigated. A SCH mouse model was established by feeding mice methimazole. Both primary endothelial cells (ECs) and HUVECs were cultured. The expression levels of key molecules were detected via quantitative RT-PCR, western blotting, and immunofluorescence. Wire myography was used to analyze the changes in vascular tones. A dual-luciferase assay was used to investigate the relationship between lncRNAs, microRNAs and target genes. In detail, it was shown that the expression levels of miR-126-3p were significantly decreased in both the SCH vasculature and HUVECs. MiR-126 supplementation suppressed HUVEC apoptosis and improved vascular function. Moreover, miR-126 could bind to the 3'-untranslated region of TRAF7, thus, regulating the C-FLIP pathway and endothelial apoptosis. Furthermore, lncRNA NEAT1 was upregulated upon TSH treatment and could function as a ceRNA and bind to miR-126, thus, modulating its expression level and vascular function. Finally, the NEAT1/miR-126/TRAF7 axis functions in response to TSH and regulates endothelial functions in SCH in vitro and in vivo. In conclusion, dysregulation of the NEAT1/miR-126/TRAF7 axis is responsible for impaired endothelial functions in SCH. Targeting this axis might become a promising treatment strategy or improving endothelial functions in SCH.