Background: This prospective clinical case series aimed to investigate the safety of subretinal adipose tissue-derived mesenchymal stem cell (ADMSC) implantation in advanced stage retinitis pigmentosa (RP). Methods: This study included 11 patients with end-stage RP who received subretinal implantation of ADMSCs. All patients had a total visual field defect and five of them only had light perception. The best corrected visual acuity (BCVA) in the study was 20/2000. All patients had undetectable electroretinography (ERG). The worst eye of the patient was operated on and, after total vitrectomy with a 23 gauge, ADMSCs were injected subretinally. Patients were evaluated at day 1, at weeks 1–4, and then once a month for 6 months, postoperatively. BCVA, anterior segment and fundus examination, color photography, and optical coherence tomography (OCT) were carried out at each visit. Fundus fluorescein angiography (FFA), perimetry, and ERG recordings were performed before treatment and at the end of month 6, and anytime if necessary during the follow-up. Results: All 11 patients completed the 6-month follow-up. None of them had systemic complications. Five patients had no ocular complications. One of the patients experienced choroidal neovascular membrane (CNM) at the implantation site and received an intravitreal anti-vascular endothelial growth factor drug once. Five patients had epiretinal membrane around the transplantation area and at the periphery, and received a second vitrectomy and silicon oil injection. There was no statistically significant difference in BCVA and ERG recordings from baseline. Only one patient experienced an improvement in visual acuity (from 20/2000 to 20/200), visual field, and ERG. Three patients mentioned that the light and some colors were brighter than before and there was a slight improvement in BCVA. The remaining seven patients had no BCVA improvement (five of them only had light perception before surgery). Conclusions: Stem cell treatment with subretinal implantation of ADMSCs seems to have some ocular complications and should be applied with caution. The results of this study provide the first evidence of the short-term safety of ADMSCs in humans, and clarifies the complications of the therapy which would be beneficial for future studies. To optimize the cell delivery technique and to evaluate the effects of this therapy on visual acuity and the quality of life of these patients, future studies with a larger number of cases will be necessary.

Autism spectrum disorder (ASD) is a group of developmental pathologies that impair social communication and cause repetitive behaviors. The suggested roles of noncoding RNAs in pathology led us to perform a comparative analysis of the microRNAs expressed in the serum of human ASD patients. The analysis of a cohort of 45 children with ASD revealed that six microRNAs (miR-19a-3p, miR-361-5p, miR-3613-3p, miR-150-5p, miR-126-3p, and miR-499a-5p) were expressed at low to very low levels compared to those in healthy controls. A similar but less pronounced decrease was registered in the clinically unaffected parents of the sick children and in their siblings but never in any genetically unrelated control. Results consistent with these observations were obtained in the blood, hypothalamus and sperm of two of the established mouse models of ASD: valproic acid-treated animals and Cc2d1a^+/− heterozygotes. In both instances, the same characteristic miRNA profile was evidenced in the affected individuals and inherited together with disease symptoms in the progeny of crosses with healthy animals. The consistent association of these genetic regulatory changes with the disease provides a starting point for evaluating the changes in the activity of the target genes and, thus, the underlying mechanism(s). From the applied societal and medical perspectives, once properly confirmed in large cohorts, these observations provide tools for the very early identification of affected children and progenitors.