Prevalence and genetic analysis of triplicated α-globin gene in Ganzhou region using high-throughput sequencing.

α-globin gene triplication carriers were not anemic in general, while some studies found that α-globin gene triplication coinherited with heterozygous ß-thalassemia may cause adverse clinical symptoms, which yet lacks sufficient evidence in large populations. In this study, we investigated the prevalence and distribution of α-globin gene triplication as well as the phenotypic characteristics of α-globin gene triplication coinherited with heterozygous ß-thalassemia in Ganzhou city, southern China. During 2021-2022, a total of 73,967 random individuals who received routine health examinations before marriage were genotyped for globin gene mutations by high-throughput sequencing. Among them, 1,443 were α-globin gene triplication carriers, with a carrier rate of 1.95%. The most prevalent mutation was αααanti3.7/αα (43.10%), followed by αααanti4.2/αα (38.12%). 42 individuals had coinherited α-globin gene triplication and heterozygous ß-thalassemia. However, they did not differ from the individuals with heterozygous ß-thalassemia and normal α-globin (αα/αα) in terms of mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) levels. In addition, heterogenous clinical phenotypes were found in two individuals with the same genotype. Our study established a database of Ganzhou α-globin gene triplication and provided practical advice for the clinical diagnosis of α-globin gene triplication.

Cortical Deficits are Correlated with Impaired Stereopsis in Patients with Strabismus.

In this study, we explored the neural mechanism underlying impaired stereopsis and possible functional plasticity after strabismus surgery. We enrolled 18 stereo-deficient patients with intermittent exotropia before and after surgery, along with 18 healthy controls. Functional magnetic resonance imaging data were collected when participants viewed three-dimensional stimuli. Compared with controls, preoperative patients showed hypoactivation in higher-level dorsal (visual and parietal) areas and ventral visual areas. Pre- and postoperative activation did not significantly differ in patients overall; patients with improved stereopsis showed stronger postoperative activation than preoperative activation in the right V3A and left intraparietal sulcus. Worse stereopsis and fusional control were correlated with preoperative hypoactivation, suggesting that cortical deficits along the two streams might reflect impaired stereopsis in intermittent exotropia. The correlation between improved stereopsis and activation in the right V3A after surgery indicates that functional plasticity may underlie the improvement of stereopsis. Thus, additional postoperative strategies are needed to promote functional plasticity and enhance the recovery of stereopsis.

Augmented-Dose Unilateral Recession-Resection Procedure in Acute Acquired Comitant Esotropia.

PURPOSE: To compare the surgical amount of unilateral medial rectus recession and lateral rectus resection (RR) in patients with acute acquired comitant esotropia (AACE) versus common forms of esotropia and to provide dose-response reference for surgical planning in AACE. DESIGN: Retrospective study. PARTICIPANTS: Consecutive patients who underwent unilateral RR for AACE or common forms of esotropia correction from January 2018 to January 2022. Only patients who achieved motor and sensory success with a minimum follow-up of 3 months were analyzed. METHODS: Group differences in the amount of medial rectus (MR) recession and lateral rectus (LR) resection were analyzed using multivariate regression models. Surgical dose responses in AACE were analyzed using multivariable regression models. Regression models were performed with and without adjustment for clinical confounders. Piecewise analysis was used to detect segmented results. MAIN OUTCOME MEASURES: Group difference in surgical amount and dose responses of unilateral RR in AACE. RESULTS: Fifty-four patients with AACE and 98 patients with common forms of esotropia were included. To correct comparable deviations, surgical amount performed was significant larger in AACE patients, with the adjusted group differences of 0.49 mm (95% confidence interval [CI], 0.34-0.65 mm; P < 0.001) in MR recession and 1.68 mm (95% CI, 1.25-2.11 mm; P < 0.001) in LR resection in patients with deviation < 40 prism diopters (Δ) and with a group difference of 1.22 mm (95% CI, 0.76-1.68 mm; P < 0.001) in LR resection in those with deviation ≥ 40 Δ. In AACE patients, in the adjusted model taking into account the intercept, dose responses of MR recession and LR resection in patients with deviation < 30 Δ were 5.11 Δ/mm (95% CI, 0.98-9.23 Δ/mm; P = 0.02) and 2.51 Δ/mm (95% CI, 0.57-4.45 Δ/mm; P = 0.02), respectively, and for those with deviation ≥ 30 Δ, the dose response of additional LR resection was 5.48 Δ/mm (95% CI, 4.56-6.40 Δ/mm; P < 0.001) to correct remaining deviation beyond 30 Δ. CONCLUSIONS: These findings provide quantitative evidence that augmented-dose unilateral RR should be performed in AACE for favorable surgical outcomes. The new surgical dose calculation proposed provides reference for surgical planning. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Quantitative assessment of eye movements using a binocular paradigm: comparison among amblyopic, recovered amblyopic and normal children.

BACKGROUND: To investigate the eye movement functions in children with amblyopia and recovered amblyopia by a binocular eye-tracking paradigm. METHODS: Eye movements of 135 pediatric subjects (age range: 4-14 years), including 45 amblyopic children, 45 recovered amblyopic children and 45 age-similar normal controls, were recorded under binocular viewing with corrected refractive errors (if any). The deviation of gaze positions relative to the target location was recorded as the mean from both eyes. Main outcome measures included fixation deviations (degree) along horizontal and vertical axes in the sustained fixation test (Fix-X, Fix-Y) and visually guided saccade test (Sac-X, Sac-Y), which were compared across the three groups and between each two groups. RESULTS: All the four deviations were significantly larger in the amblyopia group compared to the other two groups, indicating increased inaccuracy of sustained and post-saccadic fixations in amblyopia. However, there was no significant difference in deviations between recovered amblyopic children and normal controls. Repeated measures showed similar results overall and within each group. Mild to moderate amblyopes and severe amblyopes did not differ in the four deviations. No significant interaction was found between subject groups and clinical characteristics (age, refractive status, and anisometropia). CONCLUSION: Amblyopic children have poor eye movement functions with increased inaccuracy of sustained and post-saccadic fixations, which appear to be restored in children with recovered amblyopia. Binocular assessment of eye movements provides valuable indicators of functional recovery in amblyopia.

Paracetamol degradation via electrocatalysis with B and N co-doped reduced graphene oxide: Insight into the mechanism on catalyst surface and in solution.

This paper presents the use of B and N co-doped reduced graphene oxide (BN-GN) as an electrode for paracetamol electrochemical degradation. The reaction mechanism, focused on active sites in the atom level and dominant radical species generated through the reaction, was analyzed by characterization, density functional theory (DFT) calculation, quenching experiments, and electron paramagnetic resonance analysis. The characterization results indicated that the introduction of N and B functionalities into GN improved catalytic activity due to the generation of new surface defects, active sites, and improvement of conductivity. Results of experiments and DFT showed that co-doping of B and N greatly improved the catalytic activity, and the B atoms in C-N-B groups were identified as main active sites. The main active substances of BN-GN generated in the electrocatalytic oxidation of paracetamol in the solution were O2•- and active chlorine. The influence of O2•- and active chlorine on the efficiency/path of catalytic oxidation and the proposed mechanism were also determined for paracetamol degradation. This study provides an in-depth understanding of the mechanism of BN-GN catalysis and suggests possibilities for practical applications.

Catalytic performance and mechanism of graphene electrode doped with S and N heteroatoms for N-(4-hydroxyphenyl)ethanamide electrochemical degradation.

As operation performance of electro-oxidation is strongly influenced by feature of anode materials, apparently oriented preparation of electrode materials to maximize stable degradation efficiency would be top-priority consideration for system optimization. Recently, heteroatoms hybrid graphene is well known as one of major matrices popularly constructed onto anode modification due to its excellent electronic properties and long-term operation stability. The novelty focused on the first proposed competitive interactions between N and S species on graphene edges for improving operation efficiency. Due to the complicated characteristics of heteroatoms hybrid graphene, the mechanism of synergistic or antagonistic interactions of different heteroatoms was still open to be explored. To clarify the functions of S and N heteroatoms on graphene electrode, N and S co-doped graphene were prepared by hydrothermal method. Analyses upon characterization of materials, dominant radical species reacted through reaction, density functional theory (DFT) calculation, N-(4-hydroxyphenyl)ethanamide degradation pathway and the influence of heteroatom species on the efficiency/path of electrocatalytic oxidation and proposed mechanism were determined. The findings indicated that S doped graphene had more promising electrocatalytic activity than N, and that the co-existence of S and N converted the N species from pyrrolic N (the N species with the highest activity) into graphitic N (the N species with the least activity). Apparently, the activity of S was also repressed. With S and N co-doping, active sites for direct electrocatalytic oxidation was possibly properly placed at carbon atoms with S or hydroxyl group. Moreover, the S species and hydroxyl groups are more favorable for indirect electrocatalytic oxidation via HO• and active chlorine species generation. The analysis in-depth with the proposed mechanism was suggested as guideline for optimal design of functional electrodes.

Cholesterol-induced conformational changes in the sterol-sensing domain of the Scap protein suggest feedback mechanism to control cholesterol synthesis.

Scap is a polytopic protein of endoplasmic reticulum (ER) membranes that transports sterol regulatory element-binding proteins to the Golgi complex for proteolytic activation. Cholesterol accumulation in ER membranes prevents Scap transport and decreases cholesterol synthesis. Previously, we provided evidence that cholesterol inhibition is initiated when cholesterol binds to loop 1 of Scap, which projects into the ER lumen. Within cells, this binding causes loop 1 to dissociate from loop 7, another luminal Scap loop. However, we have been unable to demonstrate this dissociation when we added cholesterol to isolated complexes of loops 1 and 7. We therefore speculated that the dissociation requires a conformational change in the intervening polytopic sequence separating loops 1 and 7. Here we demonstrate such a change using a protease protection assay in sealed membrane vesicles. In the absence of cholesterol, trypsin or proteinase K cleaved cytosolic loop 4, generating a protected fragment that we visualized with a monoclonal antibody against loop 1. When cholesterol was added to these membranes, cleavage in loop 4 was abolished. Because loop 4 is part of the so-called sterol-sensing domain separating loops 1 and 7, these results support the hypothesis that cholesterol binding to loop 1 alters the conformation of the sterol-sensing domain. They also suggest that this conformational change helps transmit the cholesterol signal from loop 1 to loop 7, thereby allowing separation of the loops and facilitating the feedback inhibition of cholesterol synthesis. These insights suggest a new structural model for cholesterol-mediated regulation of Scap activity.

Sox7, Sox17, and Sox18 Cooperatively Regulate Vascular Development in the Mouse Retina.

Vascular development and maintenance are controlled by a complex transcriptional program, which integrates both extracellular and intracellular signals in endothelial cells. Here we study the roles of three closely related SoxF family transcription factors-Sox7, Sox17, and Sox18 -in the developing and mature mouse vasculature using targeted gene deletion on a mixed C57/129/CD1 genetic background. In the retinal vasculature, each SoxF gene exhibits a distinctive pattern of expression in different classes of blood vessels. On a mixed genetic background, vascular endothelial-specific deletion of individual SoxF genes has little or no effect on vascular architecture or differentiation, a result that can be explained by overlapping function and by reciprocal regulation of gene expression between Sox7 and Sox17. By contrast, combined deletion of Sox7, Sox17, and Sox18 at the onset of retinal angiogenesis leads to a dense capillary plexus with a nearly complete loss of radial arteries and veins, whereas the presence of a single Sox17 allele largely restores arterial identity, as determined by vascular smooth muscle cell coverage. In the developing retina, expression of all three SoxF genes is reduced in the absence of Norrin/Frizzled4-mediated canonical Wnt signaling, but SoxF gene expression is unaffected by reduced VEGF signaling in response to deletion of Neuropilin1 (Npn1). In adulthood, Sox7, Sox17, and Sox18 act in a largely redundant manner to maintain blood vessel function, as adult onset vascular endothelial-specific deletion of all three SoxF genes leads to massive edema despite nearly normal vascular architecture. These data reveal critical and partially redundant roles for Sox7, Sox17 and Sox18 in vascular growth, differentiation, and maintenance.

Tip cell-specific requirement for an atypical Gpr124- and Reck-dependent Wnt/ß-catenin pathway during brain angiogenesis.

Despite the critical role of endothelial Wnt/ß-catenin signaling during central nervous system (CNS) vascularization, how endothelial cells sense and respond to specific Wnt ligands and what aspects of the multistep process of intra-cerebral blood vessel morphogenesis are controlled by these angiogenic signals remain poorly understood. We addressed these questions at single-cell resolution in zebrafish embryos. We identify the GPI-anchored MMP inhibitor Reck and the adhesion GPCR Gpr124 as integral components of a Wnt7a/Wnt7b-specific signaling complex required for brain angiogenesis and dorsal root ganglia neurogenesis. We further show that this atypical Wnt/ß-catenin signaling pathway selectively controls endothelial tip cell function and hence, that mosaic restoration of single wild-type tip cells in Wnt/ß-catenin-deficient perineural vessels is sufficient to initiate the formation of CNS vessels. Our results identify molecular determinants of ligand specificity of Wnt/ß-catenin signaling and provide evidence for organ-specific control of vascular invasion through tight modulation of tip cell function.

Gpr124 controls CNS angiogenesis and blood-brain barrier integrity by promoting ligand-specific canonical wnt signaling.

Canonical Wnt signaling in endothelial cells (ECs) is required for vascularization of the central nervous system (CNS) and for formation and maintenance of barrier properties unique to CNS vasculature. Gpr124 is an orphan member of the adhesion G protein-coupled receptor family that is expressed in ECs and is essential for CNS angiogenesis and barrier formation via an unknown mechanism. Using canonical Wnt signaling assays in cell culture and genetic loss- and gain-of-function experiments in mice, we show that Gpr124 functions as a coactivator of Wnt7a- and Wnt7b-stimulated canonical Wnt signaling via a Frizzled receptor and Lrp coreceptor and that Gpr124-stimulated signaling functions in concert with Norrin/Frizzled4 signaling to control CNS vascular development. These experiments identify Gpr124 as a ligand-specific coactivator of canonical Wnt signaling.

The role of the hypoxia response in shaping retinal vascular development in the absence of Norrin/Frizzled4 signaling.

PURPOSE: To define the role of hypoxia and vascular endothelial growth factor (VEGF) in modifying the pattern, density, and permeability of the retinal vasculature in mouse models in which Norrin/Frizzled4 signaling is impaired. METHODS: Retinal vascular structure was analyzed in mice with mutation of Ndp (the gene coding for Norrin) or Frizzle4 (Fz4) with or without three additional perturbations: (1) retinal hyperoxia and reduction of VEGF, (2) reduced induction of VEGF in response to hypoxia, or (3) reduced responsiveness of vascular endothelial cells (ECs) to VEGF. These perturbations were produced, respectively, by (1) genetic ablation of rod photoreceptors in the retinal degeneration 1 (rd1) mutant background, (2) conditional deletion of the gene coding for hypoxia-inducible factor (HIF)-2alpha either in all neural retina cells or specifically in Müller glia, and (3) conditional deletion of the VEGF coreceptor neuropilin1 (NRP1) in ECs. RESULTS: All three conditions reduced vascular proliferation. Eliminating HIF2-alpha in Müller glia blocked VEGF induction in the inner nuclear layer, identifying HIF2-alpha as the transcription factor responsible for the hypoxia response in these cells. When Norrin/Frizzled4 signaling was eliminated, a secondary elevation in VEGF levels was required to compromise the barrier to transendothelial movement of high molecular weight compounds. CONCLUSIONS: In the absence of Norrin or Frizzled4, the vascular phenotype is determined by the primary defect in Norrin/Frizzled4 signaling (i.e., canonical Wnt signaling) and compensatory responses resulting from hypoxia. This work may be useful in guiding therapeutic strategies for the treatment of familial exudative vitreoretinopathy (FEVR).

Canonical WNT signaling components in vascular development and barrier formation.

Canonical WNT signaling is required for proper vascularization of the CNS during embryonic development. Here, we used mice with targeted mutations in genes encoding canonical WNT pathway members to evaluate the exact contribution of these components in CNS vascular development and in specification of the blood-brain barrier (BBB) and blood-retina barrier (BRB). We determined that vasculature in various CNS regions is differentially sensitive to perturbations in canonical WNT signaling. The closely related WNT signaling coreceptors LDL receptor-related protein 5 (LRP5) and LRP6 had redundant functions in brain vascular development and barrier maintenance; however, loss of LRP5 alone dramatically altered development of the retinal vasculature. The BBB in the cerebellum and pons/interpeduncular nuclei was highly sensitive to decrements in canonical WNT signaling, and WNT signaling was required to maintain plasticity of barrier properties in mature CNS vasculature. Brain and retinal vascular defects resulting from ablation of Norrin/Frizzled4 signaling were ameliorated by stabilizing ß-catenin, while inhibition of ß-catenin-dependent transcription recapitulated the vascular development and barrier defects associated with loss of receptor, coreceptor, or ligand, indicating that Norrin/Frizzled4 signaling acts predominantly through ß-catenin-dependent transcriptional regulation. Together, these data strongly support a model in which identical or nearly identical canonical WNT signaling mechanisms mediate neural tube and retinal vascularization and maintain the BBB and BRB.

Neuroprotection against Aß25-35-induced apoptosis by Salvia miltiorrhiza extract in SH-SY5Y cells.

The neurotoxicity of ß-amyloid protein (Aß) contributes significantly to the pathogenesis of Alzheimer's disease (AD), and hence the attractive therapeutic strategies focusing on the modulation of Aß-induced neurotoxicity are warranted. The present study aims to investigate the neuroprotection and underlying mechanisms by which Salvia miltiorrhiza Bunge (Lamiaceae) extract (SME) protects against Aß25-35-induced apoptosis in SH-SY5Y cells. 2h Pre-treatment of SH-SY5Y cells with SME (0.01, 0.1 or 0.2mg raw herb/ml) concentration-dependently attenuated Aß25-35-induced cell death, as evidenced by the increase in cell viability and decrease in neuronal apoptosis. In addition, SME suppressed the increased intracellular reactive oxygen species levels, decreased the protein expression of cleaved caspase-3, cytosolic cytochrome c, and Bax/Bcl-2 ratio. These findings taken together suggest that SME provides substantial neuroprotection against Aß25-35-induced neurotoxicity in SH-SY5Y cells, at least in part, via inhibiting oxidative stress and attenuating the mitochondria-dependent apoptotic pathway. The approach used in this study may also be useful for the screening of therapeutic agents for AD and other related neurodegenerative disease.

Norrin/Frizzled4 signaling in retinal vascular development and blood brain barrier plasticity.

Norrin/Frizzled4 (Fz4) signaling activates the canonical Wnt pathway to control retinal vascular development. Using genetically engineered mice, we show that precocious Norrin production leads to premature retinal vascular invasion and delayed Norrin production leads to characteristic defects in intraretinal vascular architecture. In genetic mosaics, wild-type endothelial cells (ECs) instruct neighboring Fz4(-/-) ECs to produce an architecturally normal mosaic vasculature, a cell nonautonomous effect. However, over the ensuing weeks, Fz4(-/-) ECs are selectively eliminated from the mosaic vasculature, implying the existence of a quality control program that targets defective ECs. In the adult retina and cerebellum, gain or loss of Norrin/Fz4 signaling results in a cell-autonomous gain or loss, respectively, of blood retina barrier and blood brain barrier function, indicating an ongoing requirement for Frizzled signaling in barrier maintenance and substantial plasticity in mature CNS vascular structure.

Retrotransposon Ty1 integration targets specifically positioned asymmetric nucleosomal DNA segments in tRNA hotspots.

The Saccharomyces cerevisiae genome contains about 35 copies of dispersed retrotransposons called Ty1 elements. Ty1 elements target regions upstream of tRNA genes and other Pol III-transcribed genes when retrotransposing to new sites. We used deep sequencing of Ty1-flanking sequence amplicons to characterize Ty1 integration. Surprisingly, some insertions were found in mitochondrial DNA sequences, presumably reflecting insertion into mitochondrial DNA segments that had migrated to the nucleus. The overwhelming majority of insertions were associated with the 5' regions of Pol III transcribed genes; alignment of Ty1 insertion sites revealed a strong sequence motif centered on but extending beyond the target site duplication. A strong sequence-independent preference for nucleosomal integration sites was observed, in distinction to the preferences of the Hermes DNA transposon engineered to jump in yeast and the Tf1 retrotransposon of Schizosaccharomyces pombe, both of which prefer nucleosome free regions. Remarkably, an exquisitely specific relationship between Ty1 integration and nucleosomal position was revealed by alignment of hotspot Ty1 insertion position regions to peak nucleosome positions, geographically implicating nucleosomal DNA segments at specific positions on the nucleosome lateral surface as targets, near the "bottom" of the nucleosome. The specificity is observed in the three tRNA 5'-proximal nucleosomes, with insertion frequency dropping off sharply 5' of the tRNA gene. The sites are disposed asymmetrically on the nucleosome relative to its dyad axis, ruling out several simple molecular models for Ty1 targeting, and instead suggesting association with a dynamic or directional process such as nucleosome remodeling associated with these regions.

Crystal structure of the Caenorhabditis elegans apoptosome reveals an octameric assembly of CED-4.

The CED-4 homo-oligomer or apoptosome is required for initiation of programmed cell death in Caenorhabditis elegans by facilitating autocatalytic activation of the CED-3 caspase zymogen. How the CED-4 apoptosome assembles and activates CED-3 remains enigmatic. Here we report the crystal structure of the complete CED-4 apoptosome and show that it consists of eight CED-4 molecules, organized as a tetramer of an asymmetric dimer via a previously unreported interface among AAA(+) ATPases. These eight CED-4 molecules form a funnel-shaped structure. The mature CED-3 protease is monomeric in solution and forms an active holoenzyme with the CED-4 apoptosome, within which the protease activity of CED-3 is markedly stimulated. Unexpectedly, the octameric CED-4 apoptosome appears to bind only two, not eight, molecules of mature CED-3. The structure of the CED-4 apoptosome reveals shared principles for the NB-ARC family of AAA(+) ATPases and suggests a mechanism for the activation of CED-3.