Single-cell transcriptomics reveals maturation of transplanted stem cell-derived retinal pigment epithelial cells toward native state

Transplantation of stem cell-derived retinal pigment epithelial (RPE) cells is considered a viable therapeutic option for age-related macular degeneration (AMD). Several landmark Phase I/II clinical trials have demonstrated safety and tolerability of RPE transplants in AMD patients, albeit with limited efficacy. Currently, there is limited understanding of how the recipient retina regulates the survival, maturation, and fate specification of transplanted RPE cells. To address this, we transplanted stem cell-derived RPE into the subretinal space of immunocompetent rabbits for 1 mo and conducted single-cell RNA sequencing analyses on the explanted RPE monolayers, compared to their age-matched in vitro counterparts. We observed an unequivocal retention of RPE identity, and a trajectory-inferred survival of all in vitro RPE populations after transplantation. Furthermore, there was a unidirectional maturation toward the native adult human RPE state in all transplanted RPE, regardless of stem cell resource. Gene regulatory network analysis suggests that tripartite transcription factors (FOS, JUND, and MAFF) may be specifically activated in posttransplanted RPE cells, to regulate canonical RPE signature gene expression crucial for supporting host photoreceptor function, and to regulate prosurvival genes required for transplanted RPE's adaptation to the host subretinal microenvironment. These findings shed insights into the transcriptional landscape of RPE cells after subretinal transplantation, with important implications for cell-based therapy for AMD.

SRSF3 maintains transcriptome integrity in oocytes by regulation of alternative splicing and transposable elements

The RNA-binding protein SRSF3 (also known as SRp20) has critical roles in the regulation of pre-mRNA splicing. Zygotic knockout of Srsf3 results in embryo arrest at the blastocyst stage. However, SRSF3 is also present in oocytes, suggesting that it might be critical as a maternally inherited factor. Here we identify SRSF3 as an essential regulator of alternative splicing and of transposable elements to maintain transcriptome integrity in mouse oocyte. Using 3D time-lapse confocal live imaging, we show that conditional deletion of Srsf3 in fully grown germinal vesicle oocytes substantially compromises the capacity of germinal vesicle breakdown (GVBD), and consequently entry into meiosis. By combining single cell RNA-seq, and oocyte micromanipulation with steric blocking antisense oligonucleotides and RNAse-H inducing gapmers, we found that the GVBD defect in mutant oocytes is due to both aberrant alternative splicing and derepression of B2 SINE transposable elements. Together, our study highlights how control of transcriptional identity of the maternal transcriptome by the RNA-binding protein SRSF3 is essential to the development of fertilized-competent oocytes.

Early emergence of cortical interneuron diversity in the mouse embryo

GABAergic interneurons (GABA, γ-aminobutyric acid) regulate neural-circuit activity in the mammalian cerebral cortex. These cortical interneurons are structurally and functionally diverse. Here, we use single-cell transcriptomics to study the origins of this diversity in the mouse. We identify distinct types of progenitor cells and newborn neurons in the ganglionic eminences, the embryonic proliferative regions that give rise to cortical interneurons. These embryonic precursors show temporally and spatially restricted transcriptional patterns that lead to different classes of interneurons in the adult cerebral cortex. Our findings suggest that shortly after the interneurons become postmitotic, their diversity is already patent in their diverse transcriptional programs, which subsequently guide further differentiation in the developing cortex.

A case report of atypical nodular cutaneous lupus mucinosis

RATIONAL

Nodular cutaneous lupus mucinosis is regarded as a distinctive cutaneous mucinosis deposition with systemic lupus erythematosus(SLE). All typical cases occurred as asymptomatic cutaneous papules, nodules, or plaques on the trunk, upper and lower extremities, and face. Histopathology is mainly revealed abundant mucin deposits among splayed collagen bundles in the dermis. At the same time we can find A the typical clinical manifestations and biological evidence of SLE. Here, we report the first case of nodular cutaneous lupus mucinosis that did not present with any prior symptoms or history of SLE.

PATIENT CONCERNS

We report the first case of nodular cutaneous lupus mucinosis that did not present with any prior symptoms or history of SLE. The patient was 34 years old. One year before admission, nodules began to appear on the elbows, chest, and back, and 2 months before admission erythema occurred on the face. Other notable clinical symptoms were not observed and had no prior history of SLE.

DIAGNOSES

Initially, this patient was misdiagnosed by other clinics as having eczema. After histopathological assessment of skin biopsy and examination of antinuclear antibody signals, the patient was correctly diagnosed with nodular cutaneous lupus mucinosis.

INTERVENTIONS

Followed administration of systemic steroids and hydroxychloroquine.

OUTCOMES

the eruptions quickly disappeared and laboratory indicators improved.

LESSONS

This case highlights the need for diagnostic vigilance in cases involving papules and nodules initially developing on the chest and elbows in the absence of obvious lupoid symptoms. We recommend a lower threshold for performing histopathological analysis and examination of antinuclear antibody signals in view of the rare but serious possibility of nodular cutaneous lupus mucinosis.

Parallel single-cell sequencing links transcriptional and epigenetic heterogeneity

We report scM&T-seq, a method for parallel single-cell genome-wide methylome and transcriptome sequencing, allowing discovery of associations between transcriptional and epigenetic variation. Profiling of 61 mouse embryonic stem cells confirmed known links between DNA methylation and transcription. Notably, the method reveals novel associations between heterogeneously methylated distal regulatory elements and transcription of key pluripotency genes.

Defining the three cell lineages of the human blastocyst by single-cell RNA-seq

There were errors published in Development 142, 3151-3165.In the issue published online on 22 September 2015, Fig. 3 was mislabelled: panels A, B, C and D should have been B, C, D and A, respectively. In the legend, the text prior to ‘(A) Cytoscape enrichment map…’ should not have been included. The correct version of the figure and legend now appear online and in print.We apologise to the authors and readers for this mistake.

Defining the three cell lineages of the human blastocyst by single-cell RNA-seq

Here, we provide fundamental insights into early human development by single-cell RNA-sequencing of human and mouse preimplantation embryos. We elucidate conserved transcriptional programs along with those that are human specific. Importantly, we validate our RNA-sequencing findings at the protein level, which further reveals differences in human and mouse embryo gene expression. For example, we identify several genes exclusively expressed in the human pluripotent epiblast, including the transcription factor KLF17. Key components of the TGF-β signalling pathway, including NODAL, GDF3, TGFBR1/ALK5, LEFTY1, SMAD2, SMAD4 and TDGF1, are also enriched in the human epiblast. Intriguingly, inhibition of TGF-β signalling abrogates NANOG expression in human epiblast cells, consistent with a requirement for this pathway in pluripotency. Although the key trophectoderm factors Id2, Elf5 and Eomes are exclusively localized to this lineage in the mouse, the human orthologues are either absent or expressed in alternative lineages. Importantly, we also identify genes with conserved expression dynamics, including Foxa2/FOXA2, which we show is restricted to the primitive endoderm in both human and mouse embryos. Comparison of the human epiblast to existing embryonic stem cells (hESCs) reveals conservation of pluripotency but also additional pathways more enriched in hESCs. Our analysis highlights significant differences in human preimplantation development compared with mouse and provides a molecular blueprint to understand human embryogenesis and its relationship to stem cells.

Summary: Single-cell RNA-sequencing of human and mouse embryos reveals conserved and human-specific transcriptional programmes as well as a functional requirement for TGFβ signalling in human embryos.

[Artificial reconstituted pulmonary surfactant used for prevention and treatment of adult respiratory distress syndrome. II. Bioluminescence method for optimizing formulation]

Based on optimizing the formulations of artificial reconstituted pulmonary surfactant (APS) used for the prevention and treatment of adult respiratory distress syndrome (ARDS) by a surface chemical method, a quartz lung animal model to obtain active alveolar macrophages (AMs) was established, using a bioluminescence technique to optimize APS's formulation according to the free-radical-scavenging abilities of APS. An optimal formulation was obtained, which showed good surface properties and free-radical-scavenging abilities. The APS preparation will be used in ARDS animal model test.

Pneumoconiosis: the changes of peripheral airways

Ultrathin bronchofiberscope (Olympus BF-1.8T) was applied to the observation of the peripheral airways of total 87 cases, including 73 cases of quartz-exposed and asbestos-exposed workers with/without pneumoconiosis (exposure groups), and 14 cases of controls. The changes of peripheral airways in exposure group of non-smokers was found, mainly to be pigmentation, elevation, irregularity and lustlessness on the surface of the bronchiole walls, and predominantly stenosis and ectasis of the lumen. The detectable rate was higher in peripheral airways than in central airways. Some changes existed in early stage and some had a tendency of increasing detectable rate with category progressing. Some factors such as smoking could influence the results of analysis.