Macular vessel density in the superficial plexus is not associated to cerebrospinal fluid core biomarkers for Alzheimer's disease in individuals with mild cognitive impairment: The NORFACE cohort.

Background: Optical coherence tomography angiography (OCT-A) is a novel method in the dementia field that allows the detection of retinal vascular changes. The comparison of OCT-A measures with established Alzheimer's disease (AD)-related biomarkers is essential to validate the former as a marker of cerebrovascular impairment in the AD continuum. We aimed to investigate the association of macular vessel density (VD) in the superficial plexus quantified by OCT-A with the AT(N) classification based on cerebrospinal fluid (CSF) Aß1-42, p181-tau and t-tau measurements in individuals with mild cognitive impairment (MCI). Materials and methods: Clinical, demographic, ophthalmological, OCT-A and CSF core biomarkers for AD data from the Neuro-ophthalmology Research at Fundació ACE (NORFACE) project were analyzed. Differences in macular VD in four quadrants (superior, nasal, inferior, and temporal) among three AT(N) groups [Normal, Alzheimer and Suspected non-Alzheimer pathology (SNAP)] were assessed in a multivariate regression model, adjusted for age, APOE ε4 status, hypertension, diabetes mellitus, dyslipidemia, heart disease, chronic obstructive pulmonary disease and smoking habit, using the Normal AT(N) group as the reference category. Results: The study cohort comprised 144 MCI participants: 66 Normal AT(N), 45 Alzheimer AT(N) and 33 SNAP AT(N). Regression analysis showed no significant association of the AT(N) groups with any of the regional macular VD measures (all, p > 0.16). The interaction between sex and AT(N) groups had no effect on differentiating VD. Lastly, CSF Aß1-42, p181-tau and t-tau measures were not correlated to VD (all r < 0.13; p > 0.13). Discussion: Our study showed that macular VD measures were not associated with the AT(N) classification based on CSF biomarkers in patients with MCI, and did not differ between AD and other underlying causes of cognitive decline in our cohort.

The Synergic Effect of AT(N) Profiles and Depression on the Risk of Conversion to Dementia in Patients with Mild Cognitive Impairment.

Few studies have addressed the impact of the association between Alzheimer's disease (AD) biomarkers and NPSs in the conversion to dementia in patients with mild cognitive impairment (MCI), and no studies have been conducted on the interaction effect of these two risk factors. AT(N) profiles were created using AD-core biomarkers quantified in cerebrospinal fluid (CSF) (normal, brain amyloidosis, suspected non-Alzheimer pathology (SNAP) and prodromal AD). NPSs were assessed using the Neuropsychiatric Inventory Questionnaire (NPI-Q). A total of 500 individuals with MCI were followed-up yearly in a memory unit. Cox regression analysis was used to determine risk of conversion, considering additive and multiplicative interactions between AT(N) profile and NPSs on the conversion to dementia. A total of 224 participants (44.8%) converted to dementia during the 2-year follow-up study. Pathologic AT(N) groups (brain amyloidosis, prodromal AD and SNAP) and the presence of depression and apathy were associated with a higher risk of conversion to dementia. The additive combination of the AT(N) profile with depression exacerbates the risk of conversion to dementia. A synergic effect of prodromal AD profile with depressive symptoms is evidenced, identifying the most exposed individuals to conversion among MCI patients.

Diagnosis of Rapidly Progressive Dementia in a Referral Center in Argentina.

INTRODUCTION: Rapidly progressive dementia (RPD) is a broadly defined clinical syndrome. Our aim was to describe clinical and ancillary study findings in patients with RPD and evaluate their diagnostic performance for the identification of nonchronic neurodegenerative rapidly progressive dementia (ncnRPD). METHODS: We reviewed clinical records and ancillary methods of patients evaluated for RPD at our institution in Buenos Aires, Argentina from 2011 to 2017. We compared findings between chronic neurodegenerative RPD and ncnRPD and evaluated the diagnostic metrics using receiver operating characteristic curves. RESULTS: We included 104 patients with RPD, 29 of whom were chronic neurodegenerative RPD and 75 of whom were ncnRPD. The 6-month time to dementia cutpoint had a sensitivity of 89% and specificity of 100% for ncnRPD, with an area under the receiver operating characteristic curve of 0.965 (95% confidence interval=0.935-0.99; P<0.001). A decision tree that included time to dementia, brain magnetic resonance imaging, and cerebrospinal fluid analysis identified ncnRPD patients with a sensitivity of 100%, specificity of 79%, positive predictive value of 93%, and negative predictive value of 100% overall. DISCUSSION: RPD is a clinical syndrome that comprises different diagnoses, many of them for treatable diseases. Using the time to dementia, brain magnetic resonance imaging, and cerebrospinal fluid analysis when triaging these patients could help identify those diseases that need to be studied more aggressively.

Lung mesenchymal stem cells-derived extracellular vesicles attenuate the inflammatory profile of Cystic Fibrosis epithelial cells.

BACKGROUND: Mesenchymal stromal/stem cells (MSCs) are multi-potent non-hematopoietic stem cells, residing in most tissues including the lung. MSCs have been used in therapy of chronic inflammatory lung diseases such as Cystic Fibrosis (CF), asthma, and chronic obstructive pulmonary disease (COPD) but the main beneficial effects reside in the anti-inflammatory potential of the released extracellular vesicles (EVs). Recent reports demonstrate that EVs are effective in animal model of asthma, E.coli pneumonia, lung ischemia-reperfusion, and virus airway infection among others. Despite this growing literature, the EVs effects on CF are largely unexplored. METHODS: We treated IB3-1 cells, an in vitro human model of CF, with EVs derived from human lung MSCs under basal and inflammatory conditions (TNFα stimulation). RESULTS: We demonstrated here that treatment of IB3-1 CF cell line with EVs, down-regulates transcription and protein expression of pro-inflammatory cytokines such as IL-1ß, IL-8, IL-6 under TNFα - stimulated conditions. EVs treatment upregulates the mRNA expression of PPARγ, a transcription factor controlling anti-inflammatory and antioxidant mechanisms via NF-kB and HO-1. Accordingly, NF-kB nuclear translocation is reduced resulting in impairment of the downstream inflammation cascade. In addition, the mRNA of HO-1 is enhanced together with the antioxidant defensive response of the cells. CONCLUSIONS: We conclude that the anti-inflammatory and anti-oxidant efficacy of EVs derived from lung MSCs could be mediated by up-regulation of the PPARγ axis, whose down-stream effectors (NF-kB and HO-1) are well-known modulators of these pathways. GENERAL SIGNIFICANCE: EVs could be a novel strategy to control the hyper-inflamed condition in Cystic Fibrosis.

Principles and applications of the balanced steady-state free precession sequence in small animal low-field MRI.

Magnetic resonance imaging (MRI) in small animal practice is largely based on classic two-dimensional spin-echo, inversion recovery and gradient-echo sequences which are largely limited by low spatial resolution, especially in low-field (LF)-MRI scanners. Nowadays, however, the availability of volumetric sequences can open new perspectives and enhance the diagnostic potential of this imaging modality. Balanced steady-state free precession (bSSFP) is a three-dimensional gradient-echo sequence in which image contrast is given by the ratio of T2 and T1, resulting in low soft-tissue signal, poor cerebral grey/white matter distinction and a bright signal from free fluid and fat. Such properties, along with a high signal-to-noise ratio and a very high spatial resolution deriving from acquisition of contiguous blocks of data, make this sequence perfectly suited for morphologic imaging, particularly for fluid-containing structures. Although bSSFP is widely adopted in human medical imaging, the use of this sequence in veterinary radiology is limited to anatomic studies of the inner ear and quadrigeminal cistern. This review aims to discuss the technical background of the bSSFP sequence and its possible advantageous applications in small animal LF-MRI for different specific disorders of the spine (arachnoid diverticula, small disc herniation, facet joint synovial cysts), brain (supracollicular fluid accumulation, traumatic injuries) and ligaments (complete and partial tears).

Acquired collateral venous pathways in a dog with cranial vena cava obstruction.

An 8-year-old neutered female Yorkshire terrier with mediastinal neoplasm and subsequent cranial vena cava invasion developed multiple venous collaterals from the brachiocephalic venous trunks to the caudal vena cava. Collateral venous pathways have been described in dogs with obstruction or increased blood flow resistance of the caudal vena cava but cranial vena cava collaterals have not been reported until now in veterinary patients. In this report, the CTA characteristics of such peculiar vascular routes are described and compared to similar findings reported in human medical literature. The recognition of such ancillary CT finding could help radiologists to reach a more accurate diagnosis of superior vena cava syndrome.

Image diagnosis of zoonotic onchocercosis by Onchocerca lupi.

Onchocerca lupi, a zoonotic nematode infecting the eyes of carnivores, has been increasingly reported in dogs from Europe and the USA. In order to improve the current status of knowledge on this neglected filarioid, diagnostic imaging tools (i.e., ultrasound scan, computed tomography and magnetic resonance imaging) are herein used to diagnose canine onchocercosis in two dogs, which scored positive for O. lupi microfilariae at the skin snip test and to assess the anatomical location of the nematode within the ocular apparatus. Results indicate that ultrasound tools are useful to address the diagnosis of O. lupi in dogs and to evaluate the localization of nodules or cysts containing the adult nematode.

c-Kit-positive cardiac stem cells nested in hypoxic niches are activated by stem cell factor reversing the aging myopathy.

RATIONALE: Hypoxia favors stem cell quiescence, whereas normoxia is required for stem cell activation, but whether cardiac stem cell (CSC) function is regulated by the hypoxic/normoxic state of the cell is currently unknown. OBJECTIVE: A balance between hypoxic and normoxic CSCs may be present in the young heart, although this homeostatic control may be disrupted with aging. Defects in tissue oxygenation occur in the old myocardium, and this phenomenon may expand the pool of hypoxic CSCs, which are no longer involved in myocyte renewal. METHODS AND RESULTS: Here, we show that the senescent heart is characterized by an increased number of quiescent CSCs with intact telomeres that cannot re-enter the cell cycle and form a differentiated progeny. Conversely, myocyte replacement is controlled only by frequently dividing CSCs with shortened telomeres; these CSCs generate a myocyte population that is chronologically young but phenotypically old. Telomere dysfunction dictates their actual age and mechanical behavior. However, the residual subset of quiescent young CSCs can be stimulated in situ by stem cell factor reversing the aging myopathy. CONCLUSIONS: Our findings support the notion that strategies targeting CSC activation and growth interfere with the manifestations of myocardial aging in an animal model. Although caution has to be exercised in the translation of animal studies to human beings, our data strongly suggest that a pool of functionally competent CSCs persists in the senescent heart and that this stem cell compartment can promote myocyte regeneration effectively, partly correcting the aging myopathy.

Comparative study of immune regulatory properties of stem cells derived from different tissues.

Allogeneic stem cell (SC)-based therapy is a promising tool for the treatment of a range of human degenerative and inflammatory diseases. Many reports highlighted the immune modulatory properties of some SC types, such as mesenchymal stromal cells (MSCs), but a comparative study with SCs of different origin, to assess whether immune regulation is a general SC property, is still lacking. To this aim, we applied highly standardized methods employed for MSC characterization to compare the immunological properties of bone marrow-MSCs, olfactory ectomesenchymal SCs, leptomeningeal SCs, and three different c-Kit-positive SC types, that is, amniotic fluid SCs, cardiac SCs, and lung SCs. We found that all the analyzed human SCs share a common pattern of immunological features, in terms of expression of activation markers ICAM-1, VCAM-1, HLA-ABC, and HLA-DR, modulatory activity toward purified T, B, and NK cells, lower immunogenicity of inflammatory-primed SCs as compared to resting SCs, and indoleamine-2,3-dioxygenase-activation as molecular inhibitory pathways, with some SC type-related peculiarities. Moreover, the SC types analyzed exert an anti-apoptotic effect toward not-activated immune effector cells (IECs). In addition, we found that the inhibitory behavior is not a constitutive property of SCs, but is acquired as a consequence of IEC activation, as previously described for MSCs. Thus, immune regulation is a general property of SCs and the characterization of this phenomenon may be useful for a proper therapeutic use of SCs.

Clinical-grade mesenchymal stromal cells produced under various good manufacturing practice processes differ in their immunomodulatory properties: standardization of immune quality controls.

Clinical-grade mesenchymal stromal cells (MSCs) are usually expanded from bone marrow (BMMSCs) or adipose tissue (ADSCs) using processes mainly differing in the use of fetal calf serum (FCS) or human platelet lysate (PL). We aimed to compare immune modulatory properties of clinical-grade MSCs using a combination of fully standardized in vitro assays. BMMSCs expanded with FCS (BMMSC-FCS) or PL (BMMSC-PL), and ADSC-PL were analyzed in quantitative phenotypic and functional experiments, including their capacity to inhibit the proliferation of T, B, and NK cells. The molecular mechanisms supporting T-cell inhibition were investigated. These parameters were also evaluated after pre-stimulation of MSCs with inflammatory cytokines. BMMSC-FCS, BMMSC-PL, and ADSC-PL displayed significant differences in expression of immunosuppressive and adhesion molecules. Standardized functional assays revealed that resting MSCs inhibited proliferation of T and NK cells, but not B cells. ADSC-PL were the most potent in inhibiting T-cell growth, a property ascribed to interferon-γ-dependent indoleamine 2,3-dioxygenase activity. MSCs did not stimulate allogeneic T cell proliferation but were efficiently lysed by activated NK cells. The systematic use of quantitative and reproducible validation techniques highlights differences in immunological properties of MSCs produced using various clinical-grade processes. ADSC-PL emerge as a promising candidate for future clinical trials.

Imaging diagnosis-bilateral abnormal ossification of the supraglenoid tubercle and cranial glenoid cavity in an English Setter.

An 8-month-old intact male English Setter was presented with bilateral shoulder lameness. Radiographic and CT examinations demonstrated bilateral irregular margination and separation of the supraglenoid tubercle from the scapula, with involvement of the cranial articular surface of the glenoid cavity. After 30 days of cage rest, complete fusion of proximal portions of both supraglenoid tubercles and persistent un-united cranial portions of both glenoid cavities were evident. Histopathologic findings from biopsies of glenoid cavity defects were consistent with osteochondrosis or focal chondrodysplasia.

Comparison of epithelial differentiation and immune regulatory properties of mesenchymal stromal cells derived from human lung and bone marrow.

Mesenchymal stromal cells (MSCs) reside in many organs including lung, as shown by their isolation from fetal lung tissues, bronchial stromal compartment, bronchial-alveolar lavage and transplanted lung tissues. It is still controversial whether lung MSCs can undergo mesenchymal-to-epithelial-transition (MET) and possess immune regulatory properties. To this aim, we isolated, expanded and characterized MSCs from normal adult human lung (lung-hMSCs) and compared with human bone marrow-derived MSCs (BM-hMSCs). Our results show that lung-MSCs reside at the perivascular level and do not significantly differ from BM-hMSCs in terms of immunophenotype, stemness gene profile, mesodermal differentiation potential and modulation of T, B and NK cells. However, lung-hMSCs express higher basal level of the stemness-related marker nestin and show, following in vitro treatment with retinoic acid, higher epithelial cell polarization, which is anyway partial when compared to a control epithelial bronchial cell line. Although these results question the real capability of acquiring epithelial functions by MSCs and the feasibility of MSC-based therapeutic approaches to regenerate damaged lung tissues, the characterization of this lung-hMSC population may be useful to study the involvement of stromal cell compartment in lung diseases in which MET plays a role, such as in chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis.

Defective CFTR expression and function are detectable in blood monocytes: development of a new blood test for cystic fibrosis.

BACKGROUND: Evaluation of cystic fibrosis transmembrane conductance regulator (CFTR) functional activity to assess new therapies and define diagnosis of cystic fibrosis (CF) is cumbersome. It is known that leukocytes express detectable levels of CFTR but the molecule has not been characterized in these cells. In this study we aim at setting up and validating a blood test to evaluate CFTR expression and function in leukocytes. DESCRIPTION: Western blot, PCR, immunofluorescence and cell membrane depolarization analysis by single-cell fluorescence imaging, using the potential-sensitive DiSBAC(2)(3) probe were utilized. Expression of PKA phosphorylated, cell membrane-localized CFTR was detected in non-CF monocytes, being undetectable or present in truncated form in monocytes derived from CF patients presenting with nonsense mutations. CFTR agonist administration induced membrane depolarization in monocytes isolated from non-CF donors (31 subjects) and, to a lesser extent, obligate CFTR heterozygous carriers (HTZ: 15 subjects), but it failed in monocytes from CF patients (44 subjects). We propose an index, which values in CF patients are significantly (p<0.001) lower than in the other two groups. Nasal Potential Difference, measured in selected subjects had concordant results with monocytes assay (Kappa statistic 0.93, 95%CI: 0.80-1.00). RESULTS AND SIGNIFICANCE: CFTR is detectable and is functional in human monocytes. We also showed that CFTR-associated activity can be evaluated in 5 ml of peripheral blood and devise an index potentially applicable for diagnostic purposes and both basic and translational research: from drug development to evaluation of functional outcomes in clinical trials.

Notch-3 and Notch-4 signaling rescue from apoptosis human B-ALL cells in contact with human bone marrow-derived mesenchymal stromal cells.

Although many literature data are available on the role of Notch signaling in T-cell acute lymphoblastic leukemia (ALL) biology, the importance of this molecular pathway in the development of B-lineage ALL (B-ALL) cells in the BM microenvironment is unknown so far. In this study, we used anti-Notch molecules neutralizing Abs and γ-secretase inhibitor (GSI) XII to investigate the role of the Notch signaling pathway in the promotion of human B-ALL cell survival in presence of stromal cell support. The treatment with combinations of anti-Notch molecule neutralizing Abs resulted in the decrease of B-ALL cell survival, either cultured alone or cocultured in presence of stromal cells from normal donors and B-ALL patients. Interestingly, the inhibition of Notch-3 and -4 or Jagged-1/-2 and DLL-1 resulted in a dramatic increase of apoptotic B-ALL cells by 3 days, similar to what is obtained by blocking all Notch signaling with the GSI XII. Our data suggest that the stromal cell-mediated antiapoptotic effect on B- ALL cells is mediated by Notch-3 and -4 or Jagged-1/-2 and DLL-1 in a synergistic manner.

Down syndrome fibroblasts and mouse Prep1-overexpressing cells display increased sensitivity to genotoxic stress.

PREP1 (PKNOX1) maps in the Down syndrome (DS) critical region of chromosome 21, is overexpressed in some DS tissues and might be involved in the DS phenotype. By using fibroblasts from DS patients and by overexpressing Prep1 in F9 teratocarcinoma and Prep1(i/i) MEF to single out the role of the protein, we report that excess Prep1 increases the sensitivity of cells to genotoxic stress and the extent of the apoptosis directly correlates with the level of Prep1. The apoptotic response of Prep1-overexpressing cells is mediated by the pro-apoptotic p53 protein that we show is a direct target of Prep1, as its depletion reverts the apoptotic phenotype. The induction of p53 overcomes the anti-apoptotic role of Bcl-X(L), previously shown to be also a Prep1 target, the levels of which are increased in Prep1-overexpressing cells as well. Our results provide a rationale for the involvement of PREP1 in the apoptotic phenotype of DS tissues and indicate that differences in Prep1 level can have drastic effects.