Proper spatial differentiation of retinal cell types is necessary for normal human vision. Many retinal diseases, such as Best disease and male germ cell associated kinase (MAK)-associated retinitis pigmentosa, preferentially affect distinct topographic regions of the retina. While much is known about the distribution of cell-types in the retina, the distribution of molecular components across the posterior pole of the eye has not been well-studied. To investigate regional difference in molecular composition of ocular tissues, we assessed differential gene expression across the temporal, macular, and nasal retina and retinal pigment epithelium (RPE)/choroid of human eyes using RNA-Seq. RNA from temporal, macular, and nasal retina and RPE/choroid from four human donor eyes was extracted, poly-A selected, fragmented, and sequenced as 100 bp read pairs. Digital read files were mapped to the human genome and analyzed for differential expression using the Tuxedo software suite. Retina and RPE/choroid samples were clearly distinguishable at the transcriptome level. Numerous transcription factors were differentially expressed between regions of the retina and RPE/choroid. Photoreceptor-specific genes were enriched in the peripheral samples, while ganglion cell and amacrine cell genes were enriched in the macula. Within the RPE/choroid, RPE-specific genes were upregulated at the periphery while endothelium associated genes were upregulated in the macula. Consistent with previous studies, BEST1 expression was lower in macular than extramacular regions. The MAK gene was expressed at lower levels in macula than in extramacular regions, but did not exhibit a significant difference between nasal and temporal retina. The regional molecular distinction is greatest between macula and periphery and decreases between different peripheral regions within a tissue. Datasets such as these can be used to prioritize candidate genes for possible involvement in retinal diseases with regional phenotypes.

Central serous chorioretinopathy (CSC) is characterized by leakage of fluid from the choroid into the subretinal space and, consequently, loss of central vision. The disease is triggered by endogenous and exogenous corticosteroid imbalance and psychosocial stress and is much more prevalent in men. We studied the association of genetic variation in 44 genes from stress response and corticosteroid metabolism pathways with the CSC phenotype in two independent cohorts of 400 CSC cases and 1,400 matched controls. The expression of cadherin 5 (CDH5), the major cell–cell adhesion molecule in vascular endothelium, was downregulated by corticosteroids which may increase permeability of choroidal vasculature, leading to fluid leakage under the retina. We found a significant association of four common CDH5 SNPs with CSC in male patients in both cohorts. Two common intronic variants, rs7499886:A>G and rs1073584:C>T, exhibit strongly significant associations with CSC; P = 0.00012; odds ratio (OR) = 1.5; 95%CI [1.2;1.8], and P = 0.0014; OR = 0.70; 95%CI [0.57;0.87], respectively. A common haplotype was present in 25.4% male CSC cases and in 35.8% controls (P = 0.0002; OR = 0.61, 95% CI [0.47–0.79]). We propose that genetically predetermined variation in CDH5, when combined with triggering events such as corticosteroid treatment or severe hormonal imbalance, underlie a substantial proportion of CSC in the male population.

Age-related macular degeneration (AMD) is a common, blinding disease of the elderly in which macular photoreceptor cells, retinal pigment epithelium, and choriocapillaris endothelial cells ultimately degenerate. Recent studies have found that degeneration of the choriocapillaris occurs early in this disease and that this endothelial cell dropout is concomitant with increased deposition of the complement membrane attack complex (MAC) at the choroidal endothelium. However, the impact of MAC injury to choroidal endothelial cells is poorly understood. To model this event in vitro, and to study the downstream consequences of MAC injury, endothelial cells were exposed to complement from human serum, compared to heat inactivated serum which lacks complement components. Cells exposed to complement components in human serum showed increased labeling with antibodies directed against the MAC, time and dose dependent cell death as assessed by lactate dehydrogenase assay, and increased permeability. RNA-Seq analysis following complement injury revealed increased expression of genes associated with angiogenesis including matrix metalloproteases (MMPs) 3 and 9, and VEGF-A. The MAC-induced increase in MMP9 RNA expression was validated using C5 depleted serum compared to C5 reconstituted serum. Increased levels of MMP9 were also determined using Western blot and zymography. These data suggest that, in addition to cell lysis, complement attack on choroidal endothelial cells promotes an angiogenic phenotype in surviving cells.

Background: Cultured epidermal stem cells (Epi-SCs) and skin-derived precursors (SKPs) were capable of reconstituting functional hair follicles after implantation, while the signaling pathways that regulate neogenic hair follicle formation are poorly investigated. In this study, we aimed to understand the interactions between Epi-SCs and SKPs during skin organoid formation and to uncover key signal pathways crucial for de novo hair follicle regeneration. Methods: To track their fate after transplantation, Epi-SCs derived from neonatal C57BL/6 mice were labeled with tdTomato, and SKPs were isolated from neonatal C57BL/6/GFP mice. A mixture of Epi-SCs-tdTomato and SKPs-EGFP in Matrigel was observed under two-photon microscope in culture and after implantation into excisional wounds in nude mice, to observe dynamic migrations of the cells during hair follicle morphogenesis. Signaling communications between the two cell populations were examined by RNA-Seq analysis. Potential signaling pathways revealed by the analysis were validated by targeting the pathways using specific inhibitors to observe a functional loss in de novo hair follicle formation. Results: Two-photon microscopy analysis indicated that when Epi-SCs and SKPs were mixed in Matrigel and cultured, they underwent dynamic migrations resulting in the formation of a bilayer skin-like structure (skin organoid), where Epi-SCs positioned themselves in the outer layer; when the mixture of Epi-SCs and SKPs was grafted into excisional wounds in nude mice, a bilayer structure resembling the epidermis and the dermis formed at the 5th day, and de novo hair follicles generated subsequently. RNA-Seq analysis of the two cell types after incubation in mixture revealed dramatic alterations in gene transcriptome, where PI3K-Akt signaling pathway in Epi-SCs was significantly upregulated; meanwhile, elevated expressions of several growth factors and cytokine potentially activating PI3K were found in SKPs, suggesting active reciprocal communications between them. In addition, inhibition of PI3K or Akt by specific inhibitors markedly suppressed the hair follicle regeneration mediated by Epi-SCs and SKPs. Conclusions: Our data indicate that the PI3K-Akt signaling pathway plays a crucial role in de novo hair follicle regeneration, and the finding may suggest potential therapeutic applications in enhancing hair regeneration.

Panicle length (PL) is an important trait for improving panicle architecture and grain yield in rice (Oryza sativa L.). Three populations were used to identify QTLs and candidate genes associated with PL. Four QTLs for PL were detected on chromosomes 4, 6, and 9 through linkage mapping in the recombinant inbred line population derived from a cross between the cultivars Xiushui79 (short panicle) and C-bao (long panicle). Ten SSR markers associated with PL were detected on chromosomes 2, 3, 5, 6, 8, 9, and 10 in the natural population consisting of 540 accessions collected from East and Southeast Asia. A major locus on chromosome 9 with the largest effect was identified via both linkage and association mapping. LONG PANICLE 1 (LP1) locus was delimited to a 90-kb region of the long arm of chromosome 9 through fine mapping using a single segment segregating F2 population. Two single nucleotide polymorphisms (SNPs) leading to amino acid changes were detected in the third and fifth exons of LP1. LP1 encodes a Remorin_C-containing protein of unknown function with homologs in a variety of species. Sequencing analysis of LP1 in two parents and 103 rice accessions indicated that SNP1 is associated with panicle length. The LP1 allele of Xiushui79 leads to reduced panicle length, whereas the allele of C-bao relieves the suppression of panicle length. LP1 and the elite alleles can be used to improve panicle length in rice.

The activity and survival of retinal photoreceptors depend on support functions performed by the retinal pigment epithelium (RPE) and on oxygen and nutrients delivered by blood vessels in the underlying choroid. By combining single-cell and bulk RNA sequencing, we categorized mouse RPE/choroid cell types and characterized the tissue-specific transcriptomic features of choroidal endothelial cells. We found that choroidal endothelium adjacent to the RPE expresses high levels of Indian Hedgehog and identified its downstream target as stromal GLI1+ mesenchymal stem cell–like cells. In vivo genetic impairment of Hedgehog signaling induced significant loss of choroidal mast cells, as well as an altered inflammatory response and exacerbated visual function defects after retinal damage. Our studies reveal the cellular and molecular landscape of adult RPE/choroid and uncover a Hedgehog-regulated choroidal immunomodulatory signaling circuit. These results open new avenues for the study and treatment of retinal vascular diseases and choroid-related inflammatory blinding disorders.

4D printing deforms a 2D foldable structure to another shape evolve over time by using heterogeneous material. The deformation of the 2D foldable structure is stimulated by actuators that are fabricated by shape memory materials or bilayer structures. Therefore, the deformation programming method of actuators is a critical technology in 4D printing. This paper proposes a method for programming the deformation of a temperature-driven bilayer structure actuator in 4D printing. The thermo-mechanical mechanism of the bilayer structure actuator is analyzed and three kinds of deformation behavior are modeled. Then a constitutive model with five main deformation programming parameters including the line width, the print height, the print temperature, the filled form, and the stimulation temperature is fitted by the orthogonal experiment and response surface method. The permanent deformation of the bilayer structure actuator results from the programmed parameters and time evolution of the 3D printed structure upon heating. A typical temperature shape memory material polylactic acid is used as a case study to illustrate the methodology and a desired programmed deformation is achieved.

Treatment with AREDS MVS and zinc may affect both angiogenesis and endothelial-macrophage interactions. These results suggest that AREDS vitamins and zinc ions may slow the progression of AMD, in part through the attenuation of EC activation.