Sequential morphological and functional features of retinal damage in mice exposed to different doses (40 vs. 20 mg/kg) of sodium iodate (NaIO3) were analyzed. Retinal morphology, apoptosis (TUNEL assay), and function (electroretinography; ERG) were examined at several time points after NaIO3 administration. The higher dose of NaIO3 caused progressive degeneration of the whole retinal area and total suppression of scotopic and photopic ERG. In contrast, the lower dose induced much less severe degeneration in peripheral part of retina along with a moderate decline of b- and a-wave amplitudes in ERG, corroborating the presence of regions within retina that retain their function. The peak of photoreceptor apoptosis was found on the 3rd day, but the lower dose induced more intense reaction within the central retina than in its peripheral region. In conclusion, these results indicate that peripheral area of the retina reveals better resistance to NaIO3 injury than its central part.

Aim: Recent findings suggest that chronic inflammatory processes play a role in the progression of age-related macular degeneration (AMD). Here we asked whether the development of different forms of AMD is connected with the elevation of plasma C3a-desArg concentration. Methods: We recruited 30 subjects with a clinical diagnosis of exudative AMD with newly diagnosed choroidal neovascularization (CNV), 30 subjects with dry AMD and 30 age- and sex-matched volunteers without AMD. The concentration of C3a-desArg complement compound was measured in the subjects’ peripheral blood. We evaluated the association between the level of C3a-desArg and age, sex, smoking, atherosclerosis, and hypertension. Results: We found that the levels of C3a-desArg were significantly elevated in patients with exudative AMD compared to the control group. The concentrations of C3a-desArg in patients with dry AMD were similar to those of controls. Additionally, patients and controls with documented atherosclerosis (AS) displayed significantly higher levels of C3a-desArg compared to subjects without AS. Conclusions: Our results suggest an association between systemic complement activation and the development of CNV. Moreover, we found an association of complement activation with atherosclerosis and confirmed the hypothesis that AMD can be a local manifestation of systemic disease.

Stem cells (SCs) maintain the balance among somatic cell populations in various tissues and are responsible for organ regeneration. The remarkable progress of regenerative medicine in the last few years indicates promise for the use of SCs in ophthalmic disorder treatment. This review describes the current view on hierarchy in the SC compartment and presents the latest attempts to use adult SCs in the regeneration of the retina. Research performed primarily in animal models gives hope for using similar strategies in humans. However, the search for the optimal source of SCs for cell therapy continues. We briefly discuss various potential sources of adult SCs that could be employed in regenerative medicine, particularly focusing on recently identified, very small embryonic-like SCs (VSEL-SCs). These cells are even present in the bone marrow and adult tissues of older patients and could be harvested from cord blood. We believe that VSEL-SCs, after the establishment of ex vivo expansion and differentiation protocols, could be harnessed for retina regeneration.

These findings suggest that circulating endothelial cells, together with high ET-1 content, may contribute to the development of AMD. Further prospective investigations on the mechanism involved may be relevant to the potential treatment of this disease.

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