Dystrophia retinae pigmentosa sine pigmento as a cause of early working disability

Prikazana su tri bolesnika (dva zaposlena na poslovima elektrovarioca, jedan na poslovima ljevača-talioca) kod kojih se radilo o nedijagnosticiranoj nasljednoj bolesti Dystrophia retinae pigmentosa sine pigmento prije zaposlenja, a kasnije je ta bolest bila razlog za promjenu poslova i radnih zadataka nakon kratkog radnog staža.Three cases of dystrophia retinae pigmentosa sine pigmento are described. In two welders and one founder the disease, which failed to be diagnosed at preemployment screening examination. appeared after a short period of work causing disability. The workers had to be removed from their workplaces and changed occupation

Patient-specific Alzheimer-like pathology in trisomy 21 cerebral organoids reveals BACE2 as a gene dose-sensitive AD suppressor in human brain

A population of >6 million people worldwide at high risk of Alzheimer’s disease (AD) are those with Down Syndrome (DS, caused by trisomy 21 (T21)), 70% of whom develop dementia during lifetime, caused by an extra copy of β-amyloid-(Aβ)-precursor-protein gene. We report AD-like pathology in cerebral organoids grown in vitro from non-invasively sampled strands of hair from 71% of DS donors. The pathology consisted of extracellular diffuse and fibrillar Aβ deposits, hyperphosphorylated/pathologically conformed Tau, and premature neuronal loss. Presence/absence of AD-like pathology was donor-specific (reproducible between individual organoids/iPSC lines/experiments). Pathology could be triggered in pathology-negative T21 organoids by CRISPR/Cas9-mediated elimination of the third copy of chromosome-21-gene BACE2, but prevented by combined chemical β and γ-secretase inhibition. We found that T21-organoids secrete increased proportions of Aβ-preventing (Aβ1-19) and Aβ-degradation products (Aβ1-20 and Aβ1-34). We show these profiles mirror in cerebrospinal fluid of people with DS. We demonstrate that this protective mechanism is mediated by BACE2-trisomy and cross-inhibited by clinically trialled BACE1-inhibitors. Combined, our data prove the physiological role of BACE2 as a dose-sensitive AD-suppressor gene, potentially explaining the dementia delay in ~30% of people with DS. We also show that DS cerebral organoids could be explored as pre-morbid AD-risk population detector and a system for hypothesis-free drug screens as well as identification of natural suppressor genes for neurodegenerative diseases

Dose imbalance of DYRK1A kinase causes systemic progeroid status in Down syndrome by increasing the un-repaired DNA damage and reducing LaminB1 levels.

BACKGROUND: People with Down syndrome (DS) show clinical signs of accelerated ageing. Causative mechanisms remain unknown and hypotheses range from the (essentially untreatable) amplified-chromosomal-instability explanation, to potential actions of individual supernumerary chromosome-21 genes. The latter explanation could open a route to therapeutic amelioration if the specific over-acting genes could be identified and their action toned-down. METHODS: Biological age was estimated through patterns of sugar molecules attached to plasma immunoglobulin-G (IgG-glycans, an established "biological-ageing-clock") in n = 246 individuals with DS from three European populations, clinically characterised for the presence of co-morbidities, and compared to n = 256 age-, sex- and demography-matched healthy controls. Isogenic human induced pluripotent stem cell (hiPSCs) models of full and partial trisomy-21 with CRISPR-Cas9 gene editing and two kinase inhibitors were studied prior and after differentiation to cerebral organoids. FINDINGS: Biological age in adults with DS is (on average) 18.4-19.1 years older than in chronological-age-matched controls independent of co-morbidities, and this shift remains constant throughout lifespan. Changes are detectable from early childhood, and do not require a supernumerary chromosome, but are seen in segmental duplication of only 31 genes, along with increased DNA damage and decreased levels of LaminB1 in nucleated blood cells. We demonstrate that these cell-autonomous phenotypes can be gene-dose-modelled and pharmacologically corrected in hiPSCs and derived cerebral organoids. Using isogenic hiPSC models we show that chromosome-21 gene DYRK1A overdose is sufficient and necessary to cause excess unrepaired DNA damage. INTERPRETATION: Explanation of hitherto observed accelerated ageing in DS as a developmental progeroid syndrome driven by DYRK1A overdose provides a target for early pharmacological preventative intervention strategies. FUNDING: Main funding came from the "Research Cooperability" Program of the Croatian Science Foundation funded by the European Union from the European Social Fund under the Operational Programme Efficient Human Resources 2014-2020, Project PZS-2019-02-4277, and the Wellcome Trust Grants 098330/Z/12/Z and 217199/Z/19/Z (UK). All other funding is described in details in the "Acknowledgements"

Distribution, differentiation, and survival of intravenously administered neural stem cells in a rat model of amyotrophic lateral sclerosis.

The transplantation of neural stem cells (NSCs) is a challenging therapeutic strategy for the treatment of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). To provide insight into the potential of the intravenous delivery of NSCs, we evaluated the delivery of NSCs marked with green fluorescent protein to the central nervous system (CNS) via intravenous tail vein injections in an ALS model. The injected cell fates were followed 1, 3, and 7 days after transplantation. The highest efficiency of cell delivery to the CNS was found in symptomatic ALS (up to 13%), moderate in presymptomatic ALS (up to 6%), and the lowest in wild-type animals (up to 0.3%). NSCs injected into ALS animals preferentially colonized the motor cortex, hippocampus, and spinal cord, and their differentiation was characterized by a decrease of nestin expression and the appearance of MAP2-, GFAP-, O4-, and CD68-positive cells. Tumor necrosis factor (TNF) administration increased the CNS delivery of transplanted cells in wild-type and presymptomatic, but not ALS symptomatic animals. Moreover, a TNF-related increase in NSC differentiation and survival was detected. Apoptosis was detected as the main cause of the loss of transplanted cells and it was influenced by TNF. Although 3 days after TNF treatment cell death was accelerated, TNF slowed down apoptosis after 7 days. This study provides elementary facts about the process occurring after NSCs leave the blood stream and enter the nervous tissue affected by inflammation/degeneration, which should help facilitate the planning of future bench-to-bedside translational projects.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe