The clearness of the cornea is essential for visual acuity and is guaranteed by limbal stem cell regeneration of the outer specialized epithelium and by the integrity of the inner corneal endothelium.

Limbal Stem Cell Deficiency (LSCD) leads to multiple corneal abnormalities including visual loss. Autologous Cultivated Limbal Stem Cell Transplantation is the first stem cell treatment for LSCD, approved at EU level. Here we present the results from the first EU multicenter clinical trial on EU citizens and a following step for the future restoration of other corneal areas, specifically the corneal endothelium.

The modified phenanthridine PJ34 blocks the post-translational modifications of specific proteins highly expressed in human malignant cells. This exclusively arrested mitosis in human malignant cells by inserting flaws in their mitotic spindle structure. Cancer cells were efficiently eradicated by Mitotic catastrophe cell death, while similarly treated healthy proliferating cells are spared and continue to proliferate as untreated cells. This cytotoxic effect was examined in a variety of human epithelial cancer cells in tissue culture and in xenografts. Three affected proteins were identified out of all tested proteins implicated in mitosis in epithelial malignant cells compared to healthy epithelial cells. Two kinesins, KifC1/HSET and Kif18A, and NuMA were identified. The identified kinesins are already examined for their potential cancer therapy. Blocking the post-translational modifications of NuMA exclusively prevented the protein binding capacity of NuMA in cancer cells. This prevented its clustering in the spindle poles, which stabilizes the spindles and enables the alignment of chromosomes in the spindle mid-zone. Unaligned chromosomes and dispersed NuMA and centrosomes were detected in distorted spindles of human cancer cells treated with PJ34. Mitosis was arrested in the anaphase and this lead to cell death via cytochrome-c release activating caspase cascades. Thus, the cytotoxic activity of PJ34 unveiled a new mechanism causing self-eradication of human cancer cells, including cancer cells that are not responsive to current therapies.

Cohen-Armon, Drug Discovery Today, 27; 1205-1209, 2022

The effect of the toxic amino acid homocysteine on both: mother and embryo causes disruption of placental blood flow and can lead to disturbances of the brain formation in offspring. The molecular and cellular mechanisms of these effects are poorly studied. The effects of maternal hyperhomocysteinemia (mHHC) on the neuronal migration, neural tissue maturation and expression of some neuronal genes were analyzed. mHHC was induced in female rats by per os administration of 0.15% aqueous methionine solution from the 4th day of pregnancy until delivery. Ultrastructure of both cortical and hippocampus tissue in mHHC pups demonstrated the developmental delay, accompanied by a retardation in motor development and body weight. The absence of synaptic glomeruli in hippocampus tissue of P20 mHHC pups suggested more essential delay in development compared to the cortical tissue. Neuronal cells labeled on E14 or E18 showed decreased number and disturbed positioning, indicating mHHC disrupted both generation and radial migration of the neuroblasts into the cortical plate. In E14 mHHC fetus brain there were decreased expression of the Kdr gene (an angiogenesis system component) and increased content of SEMA3E and the MMP-2 activity level. On E20 the level of Bdnf gene expression was increased in mHHC group. The increase in proBDNF/mBDNF ratio might affect neuronal cell viability, positioning and maturation in mHHC pups. The decrease in the level of procaspase-8 with Caspase-3 activation in the brain of E20 mHHC fetuses may indicate the development of apoptosis. It can be concluded that mHHC disturbs the mechanisms of early brain development leading to the delay in brain tissue maturation in neocortex and hippocampus of pups during the first month of their postnatal ontogenesis.

More than 30% of all human malignancies are brought about by mutation in RAS proto-oncogenes (HRAS, KRAS, and NRAS) that are greatly conserved in yeast (RAS1 and RAS2). This makes yeast an efficient single-celled eukaryotic model organism to study their functions. In this current investigation, the null mutation of RAS2 gene was analyzed to find out its deleterious consequences in yeast cells based on their ability to utilize glycerol as its respiratory substrate, mtDNA mutation rate, mtDNA abundance and distribution pattern. Mutant cells grown in YPEG plates demonstrated slight respiratory deficiency than the wild type. Erythromycin-resistant assay was carried out to analyze the spontaneous mitochondrial DNA mutation rate in ras2 mutant and was found greater than the wild type. In addition, the mitochondrial DNA of both strains was also visualized under a fluorescence microscope using DAPI fluorescent stain. It was observed that mtDNA abundance was much lower than that of the wild type. Thus, the present investigation revealed that the deletion of RAS2 gene resulted in mtDNA mutation and depletion.

One of the hallmarks of microgravity-induced alterations in several cell models is an alteration of oxidative balance. Notably, also male germ cells, sensible to oxidative stress, have been shown susceptible to changes of gravitational force. To gain more insights into the mechanisms of male germ cell response to altered gravity, a 3D cell culture model was established from TCam2 cells, a seminoma cell line, and the only available in-vitro model to study mitotically active human male germ cells. TCam2 spheroids were cultured for 24 hours under unitary gravity (UG) or simulated microgravity conditions (SM), which were obtained using the Random Positioning Machine (RPM). Apoptosis and necrosis analyses performed on UG and SM exposed samples, revealed no significant differences of all the cell death markers. Notably, Mitosox assay revealed a significant oxidation of mitochondria, after microgravity exposure, at least at this culture time. In SM treated samples, gene expression levels (evaluated by Real-time PCR) of the main enzymes of the antioxidant barrier, GPX1 and NCF1, are reduced indicating an influence of SM on mitochondria function. Notably, the expression of HMOX, involved in the heme catabolism of mitochondria cytochromes, is increased. SOD, XDH, CYBA, NCF-2, TXN and TXNRD genes were not affected. The ultrastructural analysis by Transmission Electron Microscopy revealed that SM significantly altered TCam2 spheroid mitochondria, which appeared swollen and, in some cases, disrupted. Indeed, mitophagy, or mitochondrial autophagy, appears to be more represented in samples exposed to simulated microgravity. This result seems to be in line with the increase, mediated by the simulated microgravity, of the enzyme HMOX1. All together, these preliminary data demonstrate TCam2 spheroids sensitivity to acute SM exposure, strongly indicating a microgravity-dependent modulation of mitochondria morphology and activity and encourage to perform further investigations on chronical exposure to SM of TCam2 spheroids.