Apoptosis Evaluation in Circulating CD34+-Enriched Hematopoietic Stem and Progenitor Cells in Patients with Abnormally Increased Production of Endogenous Glucocorticoids in Course of Cushing's Syndrome.

Abnormalities in hematological parameters of peripheral blood have been noted in patients with endogenous Cushing's Syndrome (CS) in the corticotropin (ACTH)-dependent and ACTH-independent forms. Nevertheless, the exact mechanism of glucocorticoids (GCs) action on human hematopoiesis is still not entirely clear. The aim of the study was to determine whether endogenous excessive production of GCs could affect apoptosis of CD34+ cells enriched in hematopoietic stem and progenitor cells (HSPCs) collected from the peripheral blood of newly diagnosed CS patients. Flow cytometry, Annexin-V enzyme-linked immunosorbent assay, TUNEL assay, real-time quantitative PCR, and microarray RNA/miRNA techniques were used to characterize CS patients' HSPCs. We found that the glucocorticoid receptor (GR) protein expression levels in CS were higher than in healthy controls. A complex analysis of apoptotic status of CS patients' HSPC cells showed that GCs significantly augmented apoptosis in peripheral blood-derived CD34+ cells and results obtained using different methods to detect early and late apoptosis in analyzed cell population were consistent. CS was also associated with significant upregulation in several members of the BCL-2 superfamily and other genes associated with apoptosis control. Furthermore, global gene expression analysis revealed significantly higher expression of genes associated with programmed cell death control in HSPCs from CS patients. These findings suggest that human endogenous GCs have a direct pro-apoptotic activity in hematopoietic CD34+ cells derived from CS subjects before treatment.

Comparative Analysis of Global Gene Expression and Complement Components Levels in Umbilical Cord Blood from Preterm and Term Neonates: Implications for Significant Downregulation of Immune Response Pathways related to Prematurity.

Background: Preterm birth is the most frequent cause of neonatal death, but its aetiology remains unclear. It has been suggested that the imbalance of immunological mechanisms responsible for maintaining pregnancy is contributing to preterm birth pathogenesis. We aimed to investigate global gene expression and the levels of several complement system components in umbilical cord blood samples from preterm neonates and compare them to term newborns. We sought to examine how differentially expressed genes could affect various immune-related pathways that are believed to be crucial factors in preterm birth. Material and methods: We enrolled 27 preterm infants (<37 weeks GA) and 52 term infants (>37 weeks GA), from which umbilical cord blood samples were collected. From these samples, peripheral blood mononuclear cells were isolated and subsequent RNA isolation was performed. We used Affymetrix Human Gene 2.1 ST Array Strip for microarray experiment and DAVID resources for bioinformatics analysis of the obtained data. Concentrations of C2, C3a, C5/C5a, C9, FactorD, Properdin were measured in umbilical cord blood plasma samples using multiplex fluorescent bead-based immunoassays using Luminex technology. Results: The levels of C3a and C5/5a were significantly elevated in preterm neonates compared to term babies, whereas C9 concentration was evidently increased in term infants. The expression of 250 genes was upregulated at least 2-fold and 3781 genes were downregulated at least 2-fold in preterm neonates in comparison with term infants. Functional annotation analysis revealed that in preterm infants in comparison to term babies there was a significant downregulation of genes encoding several Toll-like receptors, interleukins and genes involved in major signalling pathways (e.g. NF-κB, MAPK, TNF, Notch, JAK) and vital cellular processes (e.g. intracellular signal transduction, protein ubiquitination, protein transport, RNA splicing, DNA-templated transcription). Conclusions: Preterm birth results in immediate and long-term complications. Our results indicate that infants born prematurely show significant differences in complement components concentration and a downregulation of over 3,000 genes, involved mainly in various immune-related pathways, including innate immune response, phagocytosis and TLR function, when compared to full-term babies. Further studies on larger cohorts are needed to elucidate the role of immunity in prematurity.

Differential Secretion of Angiopoietic Factors and Expression of MicroRNA in Umbilical Cord Blood from Healthy Appropriate-For-Gestational-Age Preterm and Term Newborns-in Search of Biomarkers of Angiogenesis-Related Processes in Preterm Birth.

Objectives: Premature birth, defined as less than 37 weeks gestation, affects approximately 12% of all live births around the world. Advances in neonatal care have resulted in the increased survival of infants born prematurely. Although prematurity is a known risk factor for different cardiovascular diseases, little is known about the pathophysiology of vasculature during premature gestation and angiopoietic factors network during premature birth. Aims: The objective of this study was to determine whether the profile of several pro-angiogenic and anti-angiogenic factors in umbilical cord blood (UCB) is different in healthy appropriate-for-gestational-age preterm newborns and normal term babies. The second aim of this study was to investigate the microRNA (miRNAs) expression profile in UCB from preterm labor and to detect miRNAs potentially taking part in control of angogenesis-related processes (Angio-MiRs). Methods: Using an immunobead Luminex assay, we simultaneously measured the concentration of Angiogenin, Angiopoietin-1, FGF-acidic, FGF-basic, PDGF-aa, PlGF, VEGF, VEGF-D, Endostatin, Thrombospondin-2, NGF, BDNF, GDNF, and NT-4 in UCB samples collected from the preterm (n = 27) and term (n = 52) delivery. In addition, the global microRNA expression in peripheral blood mononuclear cells (PBMCs) circulating in such UCB samples was examined in this study using microarray MiRNA technique. Results: The concentrations of five from eight measured pro-angiogenic factors (VEGF, Angiopoietin-1, PDGF-AA, FGF-a, and FGF-b) were significantly lower in UCB from preterm newborns. On the contrary, two angiostatic factors (Endostatin and Thrombospondin-2) were significantly up-regulated in preterm UCB. Among analyzed neurotrophins in preterm newborns, the elevated UCB concentration was found only in the case of GDNF, whereas BDNF was significantly reduced. Moreover, two angiopoietic factors, VEGF-D and PlGF, and two neurotrophins, NT4 and NGF, did not differ in concentration in preterm and term babies. We also discovered that among the significantly down-regulated miRNAs, there were several classical Angio-MiRs (inter alia MiR-125, MiR-126, MiR-145, MiR-150, or MiR155), which are involved in angiogenesis regulation in newborn after preterm delivery. Conclusions: This is the first report of simultaneous measurements of several angiopoietic factors in UCB collected from infants during preterm and term labor. Here, we observed that several pro-angiogenic factors were at lower concentration in UCB collected from preterm newborns than term babies. In contrast, the two measured angiostatic factors, Endostatin and Thrombospondin-2, were significantly higher in UCB from preterm babies. This can suggest that distinct pathophysiological contributions from differentially expressed various angiopoietic factors may determine the clinical outcomes after preterm birth. Especially, our angiogenesis-related molecules analysis indicates that preterm birth of healthy, appropriate-for-gestational-age newborns is an "anti-angiogenic state" that may provide an increased risk for improper development and function of cardiovascular system in the adulthood. This work also contributes to a better understanding of the role of miRNAs potentially involved in angiogenesis control in preterm newborns.

Safety and Feasibility of Lin- Cells Administration to ALS Patients: A Novel View on Humoral Factors and miRNA Profiles.

Therapeutic options for amyotrophic lateral sclerosis (ALS) are still limited. Great hopes, however, are placed in growth factors that show neuroprotective abilities (e.g., nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor (VEGF)) and in the immune modulating features, in particular, the anti-inflammatory effects. In our study we aimed to investigate whether a bone marrow-derived lineage-negative (Lin-) cells population, after autologous application into cerebrospinal fluid (CSF), is able to produce noticeable concentrations of trophic factors and inflammatory-related proteins and thus influence the clinical course of ALS. To our knowledge, the evaluation of Lin- cells transplantation for ALS treatment has not been previously reported. Early hematopoietic Lin- cells were isolated from twelve ALS patients’ bone marrow, and later, the suspension of cells was administered into the subarachnoid space by lumbar puncture. Concentrations of selected proteins in the CSF and plasma were quantified by multiplex fluorescent bead-based immunoassays at different timepoints post-transplantation. We also chose microRNAs (miRNAs) related to muscle biology (miRNA-1, miRNA-133a, and miRNA-206) and angiogenesis and inflammation (miRNA-155 and miRNA-378) and tested, for the first time, their expression profiles in the CSF and plasma of ALS patients after Lin- cells transplantation. The injection of bone marrow cells resulted in decreased concentration of selected inflammatory proteins (C3) after Lin- cells injection, particularly in patients who had a better clinical outcome. Moreover, several analyzed miRNAs have changed expression levels in the CSF and plasma of ALS patients subsequent to Lin- cells administration. Interestingly, the expression of miR-206 increased in ALS patients, while miR-378 decreased both in the CSF and plasma one month after the cells’ injection. We propose that autologous lineage-negative early hematopoietic cells injected intrathecally may be a safe and feasible source of material for transplantations to the central nervous system (CNS) environment aimed at anti-inflammatory support provision for ALS adjuvant treatment strategies. Further research is needed to evaluate whether the observed effects could significantly influence the ALS progression.

The effect of intravitreal ranibizumab on apoptosis induction in rat retinal tissue.

Purpose: Despite the rapidly accumulating knowledge on pharmacokinetic properties and dosage of ranibizumab, the influence of this vascular endothelial growth factor inhibitor on retinal cell survival/apoptosis homeostasis remains unclear. The aim of this study was to investigate the biological effects of a single intravitreal injection of ranibizumab on retinal tissue with a focus on apoptosis-related signaling pathways in the rat retina. Material and methods: Male Wistar rats were treated with an intravitreal injection of ranibizumab or anti-rat vascular endothelial growth factor antibody in the right eye. The left eyes were injected with the same volume of physiological saline. On the 3rd and 7th day post-injection, the eyes were enucleated, and the retinas were isolated for further molecular analysis of the expression of selected apoptosis-related molecules at mRNA (BAX, BCL-2) and protein (caspase-3) levels using quantitative RT-PCR and western blot techniques, respectively. Results: Following a 3-day-exposure to ranibizumab at the established concentration, the BAX/BCL-2 mRNA expression ratio was significantly increased compared to the saline-treated controls and the healthy control eyes. Furthermore, on day 3. post ranibizumab injection, caspase-3 cleavage, detected qualitatively using western blotting, confirmed potential activation of the ir­reversible phase of apoptosis. In contrast, on day 7. post-injection, there were no significant differences in the BAX/BCL-2 mRNA expression ratios or caspase-3 cleavage between different groups. Conclusions: Intravitreal administration of ranibizumab leads to a transient induction of apoptosis in retinal cells, with an onset directly after the vascular endothelial growth factor inhibitor administration and apparent down-regulation shortly afterwards. These results must be considered when intravitreal injections of ranibizumab are administered to treat retinal diseases.

Circulating hematopoietic stem cell count is a valuable predictor of prematurity complications in preterm newborns.

BACKGROUND: The frequency of preterm labour has risen over the last few years. Hence, there is growing interest in the identification of markers that may facilitate prediction and prevention of premature birth complications. Here, we studied the association of the number of circulating stem cell populations with the incidence of complications typical of prematurity. METHODS: The study groups consisted of 90 preterm (23-36 weeks of gestational age) and 52 full-term (37-41 weeks) infants. Non-hematopoietic stem cells (non-HSCs; CD45-lin-CD184+), enriched in very small embryonic-like stem cells (VSELs), expressing pluripotent (Oct-4, Nanog), early neural (ß-III-tubulin), and oligodendrocyte lineage (Olig-1) genes as well as hematopoietic stem cells (HSCs; CD45+lin-CD184+), and circulating stem/progenitor cells (CSPCs; CD133+CD34+; CD133-CD34+) in association with characteristics of prematurity and preterm morbidity were analyzed in cord blood (CB) and peripheral blood (PB) until the sixth week after delivery. Phenotype analysis was performed using flow cytometry methods. Clonogenic assays suitable for detection of human hematopoietic progenitor cells were also applied. The quantitative parameters were compared between groups by the Mann-Whitney test and between time points by the Friedman test. Fisher's exact test was used for qualitative variables. RESULTS: We found that the number of CB non-HSCs/VSELs is inversely associated with the birth weight of preterm infants. More notably, a high number of CB HSCs is strongly associated with a lower risk of prematurity complications including intraventricular hemorrhage, respiratory distress syndrome, infections, and anemia. The number of HSCs remains stable for the first six weeks of postnatal life. Besides, the number of CSPCs in CB is significantly higher in preterm infants than in full-term neonates (p < 0.0001) and extensively decreases in preterm babies during next six weeks after birth. Finally, the growth of burst-forming unit of erythrocytes (BFU-E) and colony-forming units of granulocyte-macrophage (CFU-GM) obtained from CB of premature neonates is higher than those obtained from CB of full-term infants and strongly correlates with the number of CB-derived CSPCs. CONCLUSION: We conclude that CB HSCs are markedly associated with the development of premature birth complications. Thus, HSCs ought to be considered as the potential target for further research as they may be relevant for predicting and controlling the morbidity of premature infants. Moreover, the observed levels of non-HSCs/VSELs circulating in CB are inversely associated with the birth weight of preterm infants, suggesting non-HSCs/VSELs might be involved in the maturation of fetal organism.

Long-Term Effects of Adjuvant Intravitreal Treatment with Autologous Bone Marrow-Derived Lineage-Negative Cells in Retinitis Pigmentosa.

BACKGROUND: Autologous bone marrow-derived lineage-negative (Lin-) cells present antiapoptotic and neuroprotective activity. The aim of the study was to evaluate the safety and efficacy of novel autologous Lin- cell therapy during a 12-month follow-up period. METHODS: Intravitreal injection of Lin- cells in 30 eyes with retinitis pigmentosa (RP) was performed. The fellow eyes (FEs) were considered control eyes. Functional and morphological eye examinations were performed before and 1, 3, 6, 9, and 12 months after the injection. RESULTS: Patients whose symptoms started less than 10 years ago gained 14 ± 10 letters, while those with a longer disease duration gained 2.86 ± 8.54 letters compared to baseline at the 12-month follow-up (p = 0.021). There were significantly higher differences in response densities of P1-wave amplitudes in the first ring of multifocal ERGs in treated eyes than FE recordings in all follow-up points were detected. Accordingly, the mean deviation in 10-2 static perimetry improved significantly in the treated eyes compared with fellow eyes 12 months after the procedure. The QoL scores improved significantly and lasted until the 9-month visit. CONCLUSION: Lin- cell-based therapy is safe and effective, especially for a well-selected group of RP patients who still maintained good function of the foveal cones.

Impact of Carotid Endarterectomy on Choroidal Thickness and Volume in Enhanced Depth Optical Coherence Tomography Imaging.

PURPOSE: Carotid endarterectomy (CEA) is considered an effective therapeutic method for improving ocular circulation. The choroid is a predominantly vascular tissue; thus, systemic and local vascular alterations may influence its morphology and function. The aim of the current study was to analyse changes in choroidal thickness and volume in patients with significant internal carotid artery stenosis (ICAS) before and after unilateral CEA. METHODS: The 42 eyes of the 21 asymptomatic patients included in the study were divided into two groups: those ipsilateral (EIE) and those contralateral (ECE) to CEA. All participants underwent a complete ophthalmologic examination, including enhanced depth imaging-optical coherence tomography (EDI-OCT). A comparative analysis of subfoveal thickness (CT) and choroidal volume (CV) measured in nine Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields at baseline, on the 2nd day after CEA, and in the 3rd month after CEA was performed. RESULTS: In the EIE and ECE groups, no significant differences in either CT or CV values before and on the 2nd day after the CEA were observed. In the EIE group, a significant increase in CT and CV in the 3rd month after CEA compared to baseline was noted in the specific ETDRS region. Changes in CT and CV after surgery were positively correlated with the participants' physical activity status and diastolic blood pressure and negatively correlated with the participants' age and smoking status. Additionally, the analysis of changes in CV after CEA showed a positive correlation between the EIE and ECE groups. CONCLUSIONS: CT and CV fluctuations in the central and perifoveal areas visualized with EDI-OCT enabled the observation of the processes of tissue adaptation to variable blood flow conditions.

Retinal vessel dynamic functionality in the eyes of asymptomatic patients with significant internal carotid artery stenosis.

BACKGROUND: The goal of this study was to assess the retinal microvascular function in asymptomatic patients with hemodynamically significant internal carotid artery stenosis (ICAS) and to assess the potential efficacy of carotid endarterectomy (CEA) for the improvement of vessel functionality. METHODS: Retinal vessel caliber and reactions to flicker stimulation were assessed in both eyes of 65 asymptomatic patients with unilateral hemodynamically significant ICAS and 34 healthy subjects. Subsequently, the recruited ICAS patients were referred for standard unilateral CEA procedure. The full ophthalmologic examination of both eyes and vessel analysis were performed 1 day before and 3 months after CEA. RESULTS: The venous responses to flicker stimulation were significantly lower in the EIS (eyes ipsilateral to stenosis) and ECS (eyes contralateral to stenosis) compared with those in the controls (P<0.0001 and P<0.0001, respectively). No changes were identified in retinal vascular flicker responses after CEA in both groups of eyes compared with the baseline values. We observed a decrease in CRVE (central retinal venular equivalent) after the CEA both in eyes ipsilateral (P=0.01) and contralateral (P=0.04) to CEA. Likewise, a decrease in CRAE (central retinal arteriolar equivalent) was identified in the eyes ipsilateral to CEA (P<0.001). CONCLUSIONS: This outcome strongly indicates that microvascular dysfunction is long-lasting despite the recovery of the flow in the carotid artery.

Expression of selected angiogenesis-related small microRNAs in patients with abnormally increased secretion of glucocorticoids.

INTRODUCTION: Higher cortisol levels are associated with cardiovascular morbidity and mortality in the elderly, partially resulting from biologic effects of glucocorticoids (GCs) on endothelial cells observed in an experimental setting. These features are replicated in patients with endogenous GC excess (Cushing's syndrome) or with exogenous hypercortisolism due to excessive pharmacological application of GCs. Both groups present also an increased cardiovascular disease event rate. GCs may also adversely influence recovery after myocardial infarction. Recently it was proposed that microRNAs (miRNAs) - small noncoding RNAs functioning as antisense regulators of gene expression by targeting mRNA - may have a central role in regulating endothelial function through multiple mechanisms. Thus, the purpose of this study was to evaluate the effects of chronic GC excess on the expression of selected endothelium-controlling miRNAs expressed in nucleated cells circulating in peripheral blood (PBNCs) of patients with endogenous hypercortisolism either due to corticotrophin-independent or corticotrophin-dependent Cushing's syndrome (CS). MATERIAL AND METHODS: Peripheral blood nuclear cells were collected from 35 healthy subjects and 31 patients with endogenous hypercortisolism as a source of miRNAs. A self-validated individual quantitative RT-PCR study was then performed to evaluate the expression levels of selected miRNAs in PBNCs. Additionally, endothelin-1 (ET-1) expression in peripheral blood was assessed with respect to endothelial dysfunction using Western blotting. RESULTS: The ET-1 expression levels in CS were higher than in controls, confirming endothelial dysfunction in the CS group. Furthermore, miRNA analysis revealed a significantly decreased intracellular expression of selected endothelium-related miRNAs in patients with endogenous hypercortisolism, including miRNA-17-5p, miRNA-126-3p, and miRNA-126-5p, compared to controls. In contrast, two other angiogenic miRNAs, miRNA-150-5p and miRNA-223-3p, were significantly upregulated compared to controls. CONCLUSIONS: Cardiovascular events related to hypercortisolism remain a challenging problem in medical practice. This study has demonstrated that the chronic excess of GCs in endogenous CS might induce significant dysregulation of selected miRNAs involved in the control of endothelium biology. However, the lack of knowledge about specific miRNA expression postpones the full understanding of the biological roles of such miRNAs in hypercortisolism. Moreover, dysregulated miRNAs seem to be promising targets for further research, especially to search for potential therapies for several GC-induced cardiovascular complications.

Depletion of the Third Complement Component Ameliorates Age-Dependent Oxidative Stress and Positively Modulates Autophagic Activity in Aged Retinas in a Mouse Model.

The aim of the study was to investigate the influence of complement component C3 global depletion on the biological structure and function of the aged retina. In vivo morphology (OCT), electrophysiological function (ERG), and the expression of selected oxidative stress-, apoptosis-, and autophagy-related proteins were assessed in retinas of 12-month-old C3-deficient and WT mice. Moreover, global gene expression in retinas was analyzed by RNA arrays. We found that the absence of active C3 was associated with (1) alleviation of the age-dependent decrease in retinal thickness and gradual deterioration of retinal bioelectrical function, (2) significantly higher levels of antioxidant enzymes (catalase and glutathione reductase) and the antiapoptotic survivin and Mcl-1/Bak dimer, (3) lower expression of the cellular oxidative stress marker-4HNE-and decreased activity of proapoptotic caspase-3, (4) ameliorated retinal autophagic activity with localization of ubiquitinated protein conjugates commonly along the retinal pigment epithelium (RPE) layer, and (5) significantly increased expression of several gene sets associated with maintenance of the physiological functions of the neural retina. Our findings shed light on mechanisms of age-related retinal alterations by identifying C3 as a potential therapeutic target for retinal aging.

Development of Endothelial-Specific Single Inducible Lentiviral Vectors for Genetic Engineering of Endothelial Progenitor Cells.

Endothelial progenitor cells (EPC) are able to migrate to tumor vasculature. These cells, if genetically modified, can be used as vehicles to deliver toxic material to, or express anticancer proteins in tumor. To test this hypothesis, we developed several single, endothelial-specific, and doxycycline-inducible self-inactivating (SIN) lentiviral vectors. Two distinct expression cassettes were inserted into a SIN-vector: one controlled by an endothelial lineage-specific, murine vascular endothelial cadherin (mVEcad) promoter for the expression of a transactivator, rtTA2S-M2; and the other driven by an inducible promoter, TREalb, for a firefly luciferase reporter gene. We compared the expression levels of luciferase in different vector constructs, containing either the same or opposite orientation with respect to the vector sequence. The results showed that the vector with these two expression cassettes placed in opposite directions was optimal, characterized by a robust induction of the transgene expression (17.7- to 73-fold) in the presence of doxycycline in several endothelial cell lines, but without leakiness when uninduced. In conclusion, an endothelial lineage-specific single inducible SIN lentiviral vector has been developed. Such a lentiviral vector can be used to endow endothelial progenitor cells with anti-tumor properties.

Neuroprotective and antiapoptotic activity of lineage-negative bone marrow cells after intravitreal injection in a mouse model of acute retinal injury.

We investigated effects of bone marrow-derived, lineage-negative cell (Lin(-)BMC) transplantation in acute retinal injury. Lin(-)BMCs were intravitreally injected into murine eyes at 24 h after NaIO3-induced injury. Morphology, function, and expression of apoptosis-related genes, including brain-derived neurotrophic factor (BDNF) and its receptor, were assessed in retinas at 7 days, 28 days, and 3 months after transplantation. Moreover, global gene expression at day 7 was analyzed by RNA arrays. We observed that Lin(-)BMCs integrated into outer retinal layers improving morphological retinal structure and induced molecular changes such as downregulation of proapoptotic caspase-3 gene, a decrease in BAX/BCL-2 gene ratio, and significant elevation of BDNF expression. Furthermore, transplanted Lin(-)BMCs differentiated locally into cells with a macrophage-like phenotype. Finally, Lin(-)BMCs treatment was associated with generation of two distinct transcriptomic patterns. The first relates to downregulated genes associated with regulation of neuron cell death and apoptosis, response to oxidative stress/hypoxia and external stimuli, and negative regulation of cell proliferation. The second relates to upregulated genes associated with neurological system processes and sensory perception. Collectively, our data demonstrate that transplanted Lin(-)BMCs exert neuroprotective function against acute retinal injury and this effect may be associated with their antiapoptotic properties and ability to express neurotrophic factors.

Complement system in pathogenesis of AMD: dual player in degeneration and protection of retinal tissue.

Age-related macular degeneration (AMD) is the most common cause of blindness among the elderly, especially in Western countries. Although the prevalence, risk factors, and clinical course of the disease are well described, its pathogenesis is not entirely elucidated. AMD is associated with a variety of biochemical abnormalities, including complement components deposition in the retinal pigment epithelium-Bruch's membrane-choriocapillaris complex. Although the complement system (CS) is increasingly recognized as mediating important roles in retinal biology, its particular role in AMD pathogenesis has not been precisely defined. Unrestricted activation of the CS following injury may directly damage retinal tissue and recruit immune cells to the vicinity of active complement cascades, therefore detrimentally causing bystander damage to surrounding cells and tissues. On the other hand, recent evidence supports the notion that an active complement pathway is a necessity for the normal maintenance of the neurosensory retina. In this scenario, complement activation appears to have beneficial effect as it promotes cell survival and tissue remodeling by facilitating the rapid removal of dying cells and resulting cellular debris, thus demonstrating anti-inflammatory and neuroprotective activities. In this review, we discuss both the beneficial and detrimental roles of CS in degenerative retina, focusing on the diverse aspects of CS functions that may promote or inhibit macular disease.

Complement system activation and endothelial dysfunction in patients with age-related macular degeneration (AMD): possible relationship between AMD and atherosclerosis.

Age-related macular degeneration (AMD) shares several pathological and epidemiological similarities with systemic atherosclerosis (AS). First, an association between AS and AMD is apparent from the analyses of the histological and biochemical structure of atherosclerotic plaques in the vascular walls and retinal drusen, the hallmark of AMD. Second, there is considerable evidence implicating endothelial dysfunction in the pathogenesis of both disorders, and cellular oxidative stress appears to be a common denominator underlying this process. Moreover, there are observations that the complement system (CS) triggering inflammatory response contributes to the onset and advancement of both diseases. The CS plays a role in the generation of drusen and neovascularization in AMD as well as in vascular endothelium activation, cell damage and ultimately atherosclerotic plaque formation in the course of systemic arteriosclerosis. It is widely recognized that both AMD and AS are not only related to local stimulation of the CS, but also result in its systemic activation. In addition, a specific Y402H polymorphism of the complement inhibitor factor H has been found to be associated with the incidence of both AMD and AS. Here, we propose a linking hypothesis between CS activation, endothelial dysfunction and the pathogenesis of two common and age-related pathological processes, AS and AMD. We also discuss the potential therapeutic value of pharmacological modulation of CS activation in these disorders.

Bone marrow of multiorgan donors underutilized: implications for improvement of accessibility of hematopoietic cells for transplantations.

BACKGROUND: The demand for human hematopoietic stem and progenitor cells (HSPCs) for transplantation is increasing. Thus, effective alternative sources of HSPCs are required. Consequently, we sought to expand the accessibility of hematopoietic cells for clinical purposes by the investigation of hematopoietic reconstitution after transplantation of human HSPCs harvested from the bone marrow (BM) of heparinized deceased organ donors (HDODs). METHODS: For multipart research comparison, human BM HDODs-, healthy donor-derived, umbilical cord blood nuclear cells, or CD34(+) cells were transplanted into sublethally irradiated NOD/SCID mice. Twenty-eight days after transplantation nuclear cells were isolated from the murine BM, spleen, and peripheral blood and were used to quantitatively detect human CD45 antigen by quantitative real-time reverse transcriptase-polymerase chain reaction and flow cytometry. The clonogenic growth of human colony-forming units was also investigated. RESULTS: We found that umbilical cord blood-derived HSPCs showed the greatest transplantation potential in our in vivo model. Interestingly, the transplantation potential of HSPCs collected from the BM of HDODs was of the same quality as cells obtained from healthy BM donors. CONCLUSION: Based on these results, we conclude that HDODs are a strongly underappreciated source of HSPCs that are ready to use for clinical purposes.