Retinoic acid-pretreated Wharton's jelly mesenchymal stem cells in combination with triiodothyronine improve expression of neurotrophic factors in the subventricular zone of the rat ischemic brain injury

Abstract

Stroke is the consequence of limited blood flow to the brain with no established treatment to reduce the neurological deficits. Focusing on therapeutic protocols in targeting subventricular zone (SVZ) neurogenesis has been investigated recently. This study was designed to evaluate the effects of retinoic acid (RA)-pretreated Wharton's jelly mesenchymal stem cells (WJ-MSCs) in combination with triiodothyronine (T3) in the ischemia stroke model. Male Wistar rats were used to induce focal cerebral ischemia by middle cerebral artery occlusion (MCAO). There were seven groups of six animals: Sham, Ischemic, WJ-MSCs, RA-pretreated WJ-MSCs, T3, WJ-MSCs +T3, and RA-pretreated WJ-MSCs + T3. The treatment was performed at 24 h after ischemia, and animals were sacrificed one week later for assessments of retinoid X receptor β (RXRβ), brain-derived neurotrophic factor (BDNF), Sox2 and nestin in the SVZ. Pro-inflammatory cytokines in sera were measured at days four and seven after ischemia. RXRβ, BDNF, Sox2 and nestin had the significant expressions in gene and protein levels in the treatment groups, compared with the ischemic group, which were more vivid in the RA-pretreated WJ-MSCs + T3 (p ≤ 0.05). The same trend was also resulted for the levels of TNF-α and IL-6 at four days after ischemia (p ≤ 0.05). In conclusion, application of RA-pretreated WJ-MSCs + T3 could be beneficial in exerting better neurotrophic function probably via modulation of pro-inflammatory cytokines.

Keywords: Ischemia; Neurogenesis; Retinoic acid; Triiodothyronine; Wharton’s jelly mesenchymal stem cells.