Color, an important visual cue for survival, is encoded by comparing signals from photoreceptors with different spectral sensitivities. The mouse retina expresses a short wavelength-sensitive and a ...middle/long wavelength-sensitive opsin (S- and M-opsin), forming opposing, overlapping gradients along the dorsal-ventral axis. Here, we analyzed the distribution of all cone types across the entire retina for two commonly used mouse strains. We found, unexpectedly, that 'true S-cones' (S-opsin only) are highly concentrated (up to 30% of cones) in ventral retina. Moreover, S-cone bipolar cells (SCBCs) are also skewed towards ventral retina, with wiring patterns matching the distribution of true S-cones. In addition, true S-cones in the ventral retina form clusters, which may augment synaptic input to SCBCs. Such a unique true S-cone and SCBC connecting pattern forms a basis for mouse color vision, likely reflecting evolutionary adaptation to enhance color coding for the upper visual field suitable for mice's habitat and behavior.
In retinitis pigmentosa, loss of cone photoreceptors leads to blindness, and preservation of cone function is a major therapeutic goal. However, cone loss is thought to occur as a secondary event ...resulting from degeneration of rod photoreceptors. Here we report a genome editing approach in which adeno-associated virus (AAV)-mediated CRISPR/Cas9 delivery to postmitotic photoreceptors is used to target the Nrl gene, encoding for Neural retina-specific leucine zipper protein, a rod fate determinant during photoreceptor development. Following Nrl disruption, rods gain partial features of cones and present with improved survival in the presence of mutations in rod-specific genes, consequently preventing secondary cone degeneration. In three different mouse models of retinal degeneration, the treatment substantially improves rod survival and preserves cone function. Our data suggest that CRISPR/Cas9-mediated NRL disruption in rods may be a promising treatment option for patients with retinitis pigmentosa.
SP7/Osterix is a transcription factor critical for osteoblast maturation and bone formation. Homozygous loss-of-function mutations in SP7 cause osteogenesis imperfecta type XII, but neomorphic ...(gain-of-new-function) mutations of SP7 have not been reported in humans. Here we describe a de novo dominant neomorphic missense variant (c.926 C > G:p.S309W) in SP7 in a patient with craniosynostosis, cranial hyperostosis, and long bone fragility. Histomorphometry shows increased osteoblasts but decreased bone mineralization. Mice with the corresponding variant also show a complex skeletal phenotype distinct from that of Sp7-null mice. The mutation alters the binding specificity of SP7 from AT-rich motifs to a GC-consensus sequence (typical of other SP family members) and produces an aberrant gene expression profile, including increased expression of Col1a1 and endogenous Sp7, but decreased expression of genes involved in matrix mineralization. Our study identifies a pathogenic mechanism in which a mutation in a transcription factor shifts DNA binding specificity and provides important in vivo evidence that the affinity of SP7 for AT-rich motifs, unique among SP proteins, is critical for normal osteoblast differentiation.
With the increasing incidence of papillary thyroid carcinoma (PTC), PTC continues to garner attention worldwide; however its pathogenesis remains to be elucidated. The purpose of this study was to ...explore key biomarkers and potential new therapeutic targets for, PTC. GEO2R and Venn online software were used for screening of differentially expressed genes. Hub genes were screened via STRING and Cytoscape, followed by Gene Ontology and KEGG enrichment analysis. Finally, survival analysis and expression validation were performed using the UALCAN online software and immunohistochemistry. We identified 334 consistently differentially expressed genes (DEGs) comprising 136 upregulated and 198 downregulated genes. Gene Ontology enrichment analysis results suggested that the DEGs were mainly enriched in cancer-related pathways and functions. PPI network visualization was performed and 17 upregulated and 13 downregulated DEGs were selected. Finally, the expression verification and overall survival analysis conducted using the Gene Expression Profiling Interactive Analysis Tool (GEPIA) and UALCAN showed that LPAR5, TFPI, and ENTPD1 were associated with the development of PTC and the prognosis of PTC patients, and the expression of LPAR5, TFPI and ENTPD1 was verified using a tissue chip. In summary, the hub genes and pathways identified in the present study not only provide information for the development of new biomarkers for PTC but will also be useful for elucidation of the pathogenesis of PTC.
Defects in cilia centrosomal genes cause pleiotropic clinical phenotypes, collectively called ciliopathies. Cilia biogenesis is initiated by the interaction of positive and negative regulators. ...Centriolar coiled coil protein 110 (CP110) caps the distal end of the mother centriole and is known to act as a suppressor to control the timing of ciliogenesis. Here, we demonstrate that CP110 promotes cilia formation in vivo, in contrast to findings in cultured cells. Cp110(-/-) mice die shortly after birth owing to organogenesis defects as in ciliopathies. Shh signaling is impaired in null embryos and primary cilia are reduced in multiple tissues. We show that CP110 is required for anchoring of basal bodies to the membrane during cilia formation. CP110 loss resulted in an abnormal distribution of core components of subdistal appendages (SDAs) and of recycling endosomes, which may be associated with premature extension of axonemal microtubules. Our data implicate CP110 in SDA assembly and ciliary vesicle docking, two requisite early steps in cilia formation. We suggest that CP110 has unique context-dependent functions, acting as both a suppressor and a promoter of ciliogenesis.
Correlation of microstructure and intergranular stress corrosion cracking (IGSCC) susceptibility for the SA508-52M-316L dissimilar metal weld joint in primary water was investigated by the ...interrupted slow strain rate tension test following a microstructure characterization. The susceptibility to IGSCC in various regions of the dissimilar metal weld joint was observed to follow the order of Alloy 52Mb> the heat affected zone of 316L> the dilution zone of Alloy 52Mw> Alloy 52Mw weld metal. The chromium-depletion at the grain boundary is the dominant factor causing the high IGSCC susceptibility of Alloy 52Mb. However, IGSCC initiation in the heat affected zone of 316L is attributed to the increase of residual strain adjacent to the grain boundary. In addition, the decrease of chromium content and increase of residual strain adjacent to the grain boundary increase the IGSCC susceptibility of the dilution zone of Alloy 52Mw.
Ag-27.5Cu–1Ni-0.5Li foil was employed to realize transient liquid phase (TLP) diffusion bonding of C/C composite and Ti3Al alloy successfully. C/C composite|Ti3Al alloy joints without obvious defects ...were obtained under 870 °C, 10min due to sufficient element diffusion and reactions between the interlayer and parent materials. According to the analysis results of the interface structure and element distribution in joints, AgCuNiLi alloy can spread and fill the joint presenting good wettability and chemical compatibility with parent materials, as well as Ti can diffuse from Ti3Al alloy into interlayer and react with C in interfacial layer adjacent C/C composite to form reaction layer during the bonding process. As a result, the joints with gradational structure, i.e. C/C| TiC + C| Ag (s, s) |Ag (s, s) + Ti–Cu intermetallics | diffusion layer|Ti3Al can be formed, which can improve the mechanical properties of the joints effectively, and the average shear strength of the joints can reach 33.78 ± 2.84 MPa. The shear fracture surface mainly occurs in reaction layer adjacent C/C composite extending into interlayer and presents rugged morphology, which can attribute to the permeation of liquid phase in C/C composite and ragged interface.
•C/C.|Ti3Al joint was prepared by TLP diffusion bonding successfully with AgCuNiLi as interlayer.•Gradational joint can be formed due to sufficient element diffusion and reactions.•The shear strength of joints can reach 33.78 ± 2.84 MPa.•The forming process of C/C.|Ti3Al joint during TLP diffusion bonding is clarified.
Interleukin-27 is constitutively secreted by microglia in the retina or brain, and upregulation of IL-27 during neuroinflammation suppresses encephalomyelitis and autoimmune uveitis. However, while ...IL-35 is structurally and functionally similar to IL-27, the intrinsic roles of IL-35 in CNS tissues are unknown. Thus, we generated IL-35/YFP-knock-in reporter mice (p35-KI) and demonstrated that photoreceptor neurons constitutively secrete IL-35, which might protect the retina from persistent low-grade inflammation that can impair photoreceptor functions. Furthermore, the p35-KI mouse, which is hemizygous at the il12a locus, develops more severe uveitis because of reduced IL-35 expression. Interestingly, onset and exacerbation of uveitis in p35-KI mice caused by extravasation of proinflammatory Th1/Th17 lymphocytes into the retina were preceded by a dramatic decrease of IL-35, attributable to massive death of photoreceptor cells. Thus, while inflammation-induced death of photoreceptors and loss of protective effects of IL-35 exacerbated uveitis, our data also suggest that constitutive production of IL-35 in the retina might have housekeeping functions that promote sterilization immunity in the neuroretina and maintain ocular immune privilege.
Photoreceptor cells express the patatin-like phospholipase domain-containing 2 (PNPLA2) gene that codes for pigment epithelium-derived factor receptor (PEDF-R) (also known as ATGL). PEDF-R exhibits ...phospholipase activity that mediates the neurotrophic action of its ligand PEDF. Because phospholipids are the most abundant lipid class in the retina, we investigated the role of PEDF-R in photoreceptors by generating CRISPR Pnpla2 knock-out mouse lines in a retinal degeneration-free background. Pnpla2−/− mice had undetectable retinal Pnpla2 gene expression and PEDF-R protein levels as assayed by RT-PCR and immunofluorescence, respectively. The photoreceptors of mice deficient in PEDF-R had deformities as examined by histology and transmission electron microscopy. Pnpla2 knockdown diminished the PLA2 enzymatic activity of PEDF-R in the retina. Lipidomic analyses revealed the accumulation of lysophosphatidyl choline-DHA and lysophosphatidyl ethanolamine-DHA in PEDF-R-deficient retinas, suggesting a possible causal link to photoreceptor dysfunction. Loss of PEDF-R decreased levels of rhodopsin, opsin, PKCα, and synaptophysin relative to controls. Pnpla2−/− photoreceptors had surface-exposed phosphatidylserine, and their nuclei were TUNEL positive and condensed, revealing an apoptotic onset. Paralleling its structural defects, PEDF-R deficiency compromised photoreceptor function in vivo as indicated by the attenuation of photoreceptor a- and b-waves in Pnpla2−/− and Pnpla2+/− mice relative to controls as determined by electroretinography. In conclusion, ablation of PEDF-R in mice caused alteration in phospholipid composition associated with malformation and malperformance of photoreceptors. These findings identify PEDF-R as an important component for photoreceptor structure and function, highlighting its role in phospholipid metabolism for retinal survival and its consequences.
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