New Avenues to Explore in SARS-CoV-2 Infection: Both TRIM25 and TRIM56 Positively Correlate with VEGF, GAS6, and sAXL in COVID-19 Patients.

The ongoing COVID-19 pandemic poses a significant threat to human health. Many hypotheses regarding pathogenesis have been proposed and are being tried to be clarified by experimental and clinical studies. This study aimed to reveal the roles of the innate immune system modulator GAS6/sAXL pathway, endothelial dysfunction markers vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF)-1α, and antiviral effective TRIM25 and TRIM56 proteins in pathogenesis of COVID-19. The study included 55 patients with COVID-19 and 25 healthy individuals. The serum levels of GAS6, sAXL, VEGF, HIF-1α, TRIM25, and TRIM56 were measured using commercial ELISA kits and differences between COVID-19 patients and healthy controls, and the relationship to severity and prognosis were evaluated. GAS6, sAXL, TRIM56, and VEGF were found to be higher, while TRIM25 was lower in patients. There were strong positive correlations between GAS6, sAXL, TRIM25, TRIM56, and VEGF. None of the research parameters other than HIF-1α was associated with severity or prognosis. However, HIF-1α was positively correlated with APACHE II. We speculate that the antiviral effective TRIM25 and TRIM56 proteins, as well as the GAS6/sAXL pathway, act together as a defense mechanism in COVID-19. We hope that our study will contribute to further studies to elucidate the molecular mechanism associated with TRIM56, TRIM25, GAS6, sAXL, and VEGF in COVID-19 patients.

The effect of erythropoietin and umbilical cord-derived mesenchymal stem cells on nerve regeneration in rats with sciatic nerve injury.

OBJECTIVE: We aimed to investigate the effects of umbilical cord-derived mesenchymal stem cells and erythropoietin on nerve regeneration in the sciatic nerve 'crush injury' in a rat model. METHODS: Experimental animals were randomly divided into 5 groups: Crush Injury, Sham, Crush Injury + Erythropoietin, Crush Injury + Mesenchymal Stem Cell, Crush Injury + Erythropoietin + Mesenchymal Stem Cell groups. Crush injury made with bulldog clamp. Mesencyhmal stem cells delivered by enjection locally. Erythropoietin administered by intraperitoneally. On the 0th, 14th and 28th days, all groups underwent a sciatic functional index test. On 28th day, sciatic nerves were harvested and histopathological appearance, axon number and axon diameter of the sciatic nerves were evaluated with Oil Red O staining. Immunoreactivity of nerve growth factor, neurofilament-H and caspase-3 were determined by immunofluorescence staining in nerve tissue. RESULTS: In histopathological examination, axons and nerve bundles exhibiting normal nerve architecture in the Sham group. Crush Injury + Mesenchymal Stem Cell group has similar histological appearance to the Sham group. The number of axons were higher in the Mesenchymal Stem Cell groups compared to the Crush Injury group. Nerve growth factor immunoreactivity intensity was significantly lower in Crush Injury + Mesenchymal Stem Cell group compared to Crush Injury group. Neurofilament-H density was higher in the treatment groups when compared to the Crush Injury group. CONCLUSIONS: In this study, it was found that umbilical cord-derived mesenchymal stem cells and erythropoietin treatments effects positively regeneration of crush injury caused by bulldog clamp in the sciatic nerve of rats.