Display omitted
Neurotrauma, stroke, and neurodegenerative disease may result in widespread loss of neural cells as well as the complex interconnectivity necessary for proper central nervous system ...function, generally resulting in permanent functional deficits. Potential regenerative strategies involve the recruitment of endogenous neural stem cells and/or directed axonal regeneration through the use of tissue engineered “living scaffolds” built to mimic features of three-dimensional (3-D) in vivo migratory or guidance pathways. Accordingly, we devised a novel biomaterial encasement scheme using tubular hydrogel-collagen micro-columns that facilitated the self-assembly of seeded astrocytes into 3-D living scaffolds consisting of long, cable-like aligned astrocytic networks. Here, robust astrocyte alignment was achieved within a micro-column inner diameter (ID) of 180μm or 300–350μm but not 1.0mm, suggesting that radius of curvature dictated the extent of alignment. Moreover, within small ID micro-columns, >70% of the astrocytes assumed a bi-polar morphology, versus ∼10% in larger micro-columns or planar surfaces. Cell–cell interactions also influenced the aligned architecture, as extensive astrocyte-collagen contraction was achieved at high (9–12×105cells/mL) but not lower (2–6×105cells/mL) seeding densities. This high density micro-column seeding led to the formation of ultra-dense 3-D “bundles” of aligned bi-polar astrocytes within collagen measuring up to 150μm in diameter yet extending to a remarkable length of over 2.5cm. Importantly, co-seeded neurons extended neurites directly along the aligned astrocytic bundles, demonstrating permissive cues for neurite extension. These transplantable cable-like astrocytic networks structurally mimic the glial tube that guides neuronal progenitor migration in vivo along the rostral migratory stream, and therefore may be useful to guide progenitor cells to repopulate sites of widespread neurodegeneration.
This manuscript details our development of novel micro-tissue engineering techniques to generate robust networks of longitudinally aligned astrocytes within transplantable micro-column hydrogels. We report a novel biomaterial encasement scheme that facilitated the self-assembly of seeded astrocytes into long, aligned regenerative pathways. These miniature “living scaffold” constructs physically emulate the glial tube – a pathway in the brain consisting of aligned astrocytes that guide the migration of neuronal progenitor cells – and therefore may facilitate directed neuronal migration for central nervous system repair. The small size and self-contained design of these aligned astrocyte constructs will permit minimally invasive transplantation in models of central nervous system injury in future studies.
Electrocochleography (ECochG) patterns observed during cochlear implant (CI) electrode insertion may provide information about scalar location of the electrode array.
Conventional CI surgery is ...performed without actively monitoring auditory function and potential damage to intracochlear structures. The central hypothesis of this study was that ECochG obtained directly through the CI may be used to estimate intracochlear electrode position and, ultimately, residual hearing preservation.
Intracochlear ECochG was performed on 32 patients across 3 different implant centers. During electrode insertion, a 50-ms tone burst stimulus (500 Hz) was delivered at 110 dB SPL. The ECochG response was monitored from the apical-most electrode. The amplitude and phase changes of the first harmonic were imported into an algorithm in an attempt to predict the intracochlear electrode location (scala tympani ST, translocation from ST to scala vestibuli SV, or interaction with basilar membrane). Anatomic electrode position was verified using postoperative computed tomography (CT) with image processing.
CT analysis confirmed 25 electrodes with ST position and 7 electrode arrays translocating from ST into SV. The ECochG algorithm correctly estimated electrode position in 26 (82%) of 32 subjects while 6 (18%) electrodes were wrongly identified as translocated (sensitivity = 100%, specificity = 77%, positive predictive value = 54%, and a negative predictive value = 100%). Greater hearing loss was observed postoperatively in participants with translocated electrode arrays (36 ± 15 dB) when compared with isolated ST insertions (28 ± 20 dB HL). This result, however, was not significant (p = 0.789).
Intracochlear ECochG may provide information about CI electrode location and hearing preservation.
The Ecoresponsive Genome of "Daphnia pulex" Colbourne, John K.; Pfrender, Michael E.; Gilbert, Donald ...
Science (American Association for the Advancement of Science),
02/2011, Letnik:
331, Številka:
6017
Journal Article
Recenzirano
Odprti dostop
We describe the draft genome of the microcrustacean Daphnia pulex, which is only 200 megabases and contains at least 30,907 genes. The high gene count is a consequence of an elevated rate of gene ...duplication resulting in tandem gene clusters. More than a third of Daphnia's genes have no detectable homologs in any other available proteome, and the most amplified gene families are specific to the Daphnia lineage. The coexpansion of gene families interacting within metabolic pathways suggests that the maintenance of duplicated genes is not random, and the analysis of gene expression under different environmental conditions reveals that numerous paralogs acquire divergent expression patterns soon after duplication. Daphnia-specific genes, including many additional loci within sequenced regions that are otherwise devoid of annotations, are the most responsive genes to ecological challenges.
Plasma soluble prorenin receptor (sPRR) displays sexual dimorphism and is higher in women with type 2 diabetes mellitus (T2DM). However, the contribution of plasma sPRR to the development of vascular ...complications in T2DM remains unclear. We investigated if plasma sPRR contributes to sex differences in the activation of the systemic renin-angiotensin-aldosterone system (RAAS) and vascular damage in a model of high-fat diet (HFD)-induced T2DM. Male and female C57BL/6J mice were fed either a normal fat diet (NFD) or an HFD for 28 wk to assess changes in blood pressure, cardiometabolic phenotype, plasma prorenin/renin, sPRR, and ANG II. After completing dietary protocols, tissues were collected from males to assess vascular reactivity and aortic reactive oxygen species (ROS). A cohort of male mice was used to determine the direct contribution of increased systemic sPRR by infusion. To investigate the role of ovarian hormones, ovariectomy (OVX) was performed at 32 wk in females fed either an NFD or HFD. Significant sex differences were found after 28 wk of HFD, where only males developed T2DM and increased plasma prorenin/renin, sPRR, and ANG II. T2DM in males was accompanied by nondipping hypertension, carotid artery stiffening, and aortic ROS. sPRR infusion in males induced vascular thickening instead of material stiffening caused by HFD-induced T2DM. While intact females were less prone to T2DM, OVX increased plasma prorenin/renin, sPRR, and systolic blood pressure. These data suggest that sPRR is a novel indicator of systemic RAAS activation and reflects the onset of vascular complications during T2DM regulated by sex.
High-fat diet (HFD) for 28 wk leads to type 2 diabetes mellitus (T2DM) phenotype, concomitant with increased plasma soluble prorenin receptor (sPRR), nondipping blood pressure, and vascular stiffness in male mice. HFD-fed female mice exhibiting a preserved cardiometabolic phenotype until ovariectomy revealed increased plasma sPRR and blood pressure. Plasma sPRR may indicate the status of systemic renin-angiotensin-aldosterone system (RAAS) activation and the onset of vascular complications during T2DM in a sex-dependent manner.
Electrocochleography (ECochG) recorded during cochlear implant (CI) insertion from the apical electrode in conjunction with postinsertion ECochG can identify electrophysiologic differences that exist ...between groups with and without a translocation of the array from the scala tympani (ST) into the scala vestibuli (SV).
Translocation of the CI electrode from ST into SV can limit performance postoperatively. ECochG markers of trauma may be able to aid in the ability to detect electrode array-induced trauma/scalar translocation intraoperatively.
Twenty-one adult CI patients were included. Subjects were postoperatively parsed into two groups based on analysis of postoperative imaging: 1) ST (n = 14) insertion; 2) SV (n = 7) insertion, indicating translocation of the electrode. The ECochG response elicited from a 500 Hz acoustic stimulus was recorded from the lead electrode during insertion when the distal electrode marker was at the round window, and was compared to the response recorded from a basal electrode (e13) after complete insertion.
No statistically significant change in mean ECochG magnitude was found in either group between recording intervals. There was a mean loss of preoperative pure-tone average of 52% for the nontranslocation group and 94% for the translocation group.
Intraoperative intracochlear ECochG through the CI array provides a unique opportunity to explore the impact of the CI electrode on the inner ear. Specifically, a translocation of the array from ST to SV does not seem to change the biomechanics of the cochlear region that lies basal to the area of translocation in the acute period.
Despite substantial morbidity and mortality, no therapeutic agents exist for treatment of dengue or Zika, and the currently available dengue vaccine is only recommended for dengue virus (DENV)-immune ...individuals. Thus, development of therapeutic and/or preventive drugs is urgently needed. DENV and Zika virus (ZIKV) nonstructural protein 1 (NS1) can directly trigger endothelial barrier dysfunction and induce inflammatory responses, contributing to vascular leak in vivo. Here we evaluated the efficacy of the (1–6,1-3)-β-D-glucan isolated from Agaricus subrufescens fruiting bodies (FR) and its sulfated derivative (FR-S) against DENV-2 and ZIKV infection and NS1-mediated pathogenesis. FR-S, but not FR, significantly inhibited DENV-2 and ZIKV replication in human monocytic cells (EC50 = 36.5 and 188.7 μg/mL, respectively) when added simultaneously with viral infection. No inhibitory effect was observed when FR or FR-S were added post-infection, suggesting inhibition of viral entry as a mechanism of action. In an in vitro model of endothelial permeability using human pulmonary microvascular endothelial cells (HPMECs), FR and FR-S (0.12 μg/mL) inhibited DENV-2 NS1- and ZIKV NS1-induced hyperpermeability by 50% and 100%, respectively, as measured by Trans-Endothelial Electrical Resistance. Treatment with 0.25 μg/mL of FR and FR-S inhibited DENV-2 NS1 binding to HPMECs. Further, FR-S significantly reduced intradermal hyperpermeability induced by DENV-2 NS1 in C57BL/6 mice and protected against DENV-induced morbidity and mortality in a murine model of dengue vascular leak syndrome. Thus, we demonstrate efficacy of FR-S against DENV and ZIKV infection and NS1-induced endothelial permeability in vitro and in vivo. These findings encourage further exploration of FR-S and other glycan candidates for flavivirus treatment alone or in combination with compounds with different mechanisms of action.
•The A. subrufescens β-glucan FR and its sulfated derivative FR-S were evaluated for anti-DENV-2, -ZIKV, and -NS1 activities.•FR-S significantly inhibited DENV-2 and ZIKV replication in human monocytic cells.•FR and FR-S inhibited DENV-2 NS1- and ZIKV NS1-induced hyperpermeability in vitro.•FR-S protected against DENV-2 NS1-induced dermal vascular leak in mice.•FR-S oral treatment reduced morbidity and mortality of mice infected with DENV-2.
Objective
Currently, there are no reliable biomarkers for predicting therapeutic response in patients with rheumatoid arthritis (RA). The synovium may unlock critical information for determining ...efficacy, since a reduction in the numbers of sublining synovial macrophages remains the most reproducible biomarker. Thus, a clinically actionable method for the collection of synovial tissue, which can be analyzed using high‐throughput strategies, must become a reality. This study was undertaken to assess the feasibility of utilizing synovial biopsies as a precision medicine‐based approach for patients with RA.
Methods
Rheumatologists at 6 US academic sites were trained in minimally invasive ultrasound‐guided synovial tissue biopsy. Biopsy specimens obtained from patients with RA and synovial tissue from patients with osteoarthritis (OA) were subjected to histologic analysis, fluorescence‐activated cell sorting, and RNA sequencing (RNA‐seq). An optimized protocol for digesting synovial tissue was developed to generate high‐quality RNA‐seq libraries from isolated macrophage populations. Associations were determined between macrophage transcriptional profiles and clinical parameters in RA patients.
Results
Patients with RA reported minimal adverse effects in response to synovial biopsy. Comparable RNA quality was observed from synovial tissue and isolated macrophages between patients with RA and patients with OA. Whole tissue samples from patients with RA demonstrated a high degree of transcriptional heterogeneity. In contrast, the transcriptional profile of isolated RA synovial macrophages highlighted different subpopulations of patients and identified 6 novel transcriptional modules that were associated with disease activity and therapy.
Conclusion
Performance of synovial tissue biopsies by rheumatologists in the US is feasible and generates high‐quality samples for research. Through the use of cutting‐edge technologies to analyze synovial biopsy specimens in conjunction with corresponding clinical information, a precision medicine–based approach for patients with RA is attainable.
We tested whether DNA-methylation profiles account for inter-individual variation in body mass index (BMI) and height and whether they predict these phenotypes over and above genetic factors. Genetic ...predictors were derived from published summary results from the largest genome-wide association studies on BMI (n ∼ 350,000) and height (n ∼ 250,000) to date. We derived methylation predictors by estimating probe-trait effects in discovery samples and tested them in external samples. Methylation profiles associated with BMI in older individuals from the Lothian Birth Cohorts (LBCs, n = 1,366) explained 4.9% of the variation in BMI in Dutch adults from the LifeLines DEEP study (n = 750) but did not account for any BMI variation in adolescents from the Brisbane Systems Genetic Study (BSGS, n = 403). Methylation profiles based on the Dutch sample explained 4.9% and 3.6% of the variation in BMI in the LBCs and BSGS, respectively. Methylation profiles predicted BMI independently of genetic profiles in an additive manner: 7%, 8%, and 14% of variance of BMI in the LBCs were explained by the methylation predictor, the genetic predictor, and a model containing both, respectively. The corresponding percentages for LifeLines DEEP were 5%, 9%, and 13%, respectively, suggesting that the methylation profiles represent environmental effects. The differential effects of the BMI methylation profiles by age support previous observations of age modulation of genetic contributions. In contrast, methylation profiles accounted for almost no variation in height, consistent with a mainly genetic contribution to inter-individual variation. The BMI results suggest that combining genetic and epigenetic information might have greater utility for complex-trait prediction.
PDF
