Comparing the potential efficacy of stromal vascular fraction and adipose mesenchymal stem cell-derived exosomes in a rat model of chromium-induced thyroid dysfunction.

BACKGROUND

Occupational exposure to toxic heavy metals may render industrial workers susceptible to thyroid-related problems. Chromium (Cr) in its hexavalent form is highly toxic and a known carcinogen. This research is the first experimental study to investigate the possible protective role of adipose mesenchymal stem cell (MSC)-derived exosomes (ADMSCs-E) versus stromal vascular fraction (SVF) exosomes in a rat model of Cr-induced thyrotoxicity, using behavioral, histological, immunohistochemical, and biochemical studies, with correlation assessed using morphometric and statistical methods.

METHODS

Forty-two male rats were randomly assigned to a donor group (n = 10) for preparation of ADMSCs-E and SVF and four experimental groups (n = 8 each): control, Chromium-treated (60 μg/kg I.P), Exosomes-treated, and SVF-treated groups. Behavioral changes were assessed through the open field and elevated plus maze (EPM) tests. Blood samples were collected to measure T3, T4, TSH, tumor necrosis factor-alpha (TNF-α), and malondialdehyde (MDA) in serum. Thyroid tissues were then subjected to histological, immunohistochemical, ultrastructural, and morphometric analyses. Additionally, Pax3 mRNA expression was evaluated using qRT-PCR.

RESULTS

Following exposure to potassium dichromate, the thyroid histological and ultrastructural architecture was significantly disrupted, leading to altered thyroid function, oxidative stress, and inflammatory responses. This was indicated by changes in thyroid hormone levels, increased MDA and TNF-α, upregulated PAX3 expression, and greater collagen fiber deposition. Immunohistochemistry revealed that the diseased group showed strong Ki67 expression and weak BCL2 expression, while the treatment groups exhibited the opposite pattern, indicating a protective effect against cellular stress and apoptosis.

CONCLUSION

Both SVF and exosomes effectively reduced Cr-induced thyroid toxicity, with no significant difference between them.