Regulation of crucial lncRNAs in differentiation of chicken embryonic stem cells to spermatogonia stem cells

Production of viable chicken by allogeneic transplantation of primordial germ cells induced from somatic cells

The allogeneic transplantation of primordial germ cells (PGCs) derived from somatic cells overcomes the limitation of avian cloning. Here, we transdifferentiate chicken embryo fibroblasts (CEFs) from black feathered Langshan chickens to PGCs and transplant them into White Plymouth Rock chicken embryos to produce viable offspring with characteristics inherited from the donor. We express Oct4/Sox2/Nanog/Lin28A (OSNL) to reprogram CEFs to induced pluripotent stem cells (iPSCs), which are further induced to differentiate into PGCs by BMP4/BMP8b/EGF. DNA demethylation, histone acetylation and glycolytic activation elevate the iPSC induction efficiency, while histone acetylation and glycolytic inhibition facilitate PGCs formation. The induced PGCs (iPGCs) are transplanted into the recipients, which are self-crossed to produce 189/509 somatic cells derived chicken with the donor's characteristics. Microsatellite analysis and genome sequencing confirm the inheritance of genetic information from the donor. Thus, we demonstrate the feasibility of avian cloning from somatic cells.

Systematic screening of long intergenic noncoding RNAs expressed during chicken embryogenesis

Long noncoding RNAs (lncRNAs) have emerged as important regulators of many biological processes, including embryogenesis and development. To provide a systematic analysis of lncRNAs expressed during chicken embryogenesis, we used Iso-Seq and RNA-Seq to identify potential lncRNAs at embryonic stages from d 1 to d 8 of incubation: sequential stages covering gastrulation, somitogenesis, and organogenesis. The data characterized an expanded landscape of lncRNAs, yielding 45,410 distinct lncRNAs (31,282 genes). Amongst these, a set of 13,141 filtered intergenic lncRNAs (lincRNAs) transcribed from 9803 lincRNA gene loci, of which, 66.5% were novel, were further analyzed. These lincRNAs were found to share many characteristics with mammalian lincRNAs, including relatively short lengths, fewer exons, lower expression levels, and stage-specific expression patterns. Functional studies motivated by "guilt-by-association" associated individual lincRNAs with specific GO functions, providing an important resource for future studies of lincRNA function. Most importantly, a weighted gene co-expression network analysis suggested that genes of the brown module were specifically associated with the day 2 stage. LincRNAs within this module were co-expressed with proteins involved in hematopoiesis and lipid metabolism. This study presents the systematic identification of lincRNAs in developing chicken embryos and will serve as a powerful resource for the study of lincRNA functions.

JUN promotes chicken female differentiation by inhibiting Smad2

The sex determination and control of poultry is a key problem in production and scientific research despite few studies on regulatory factors, especially transcription factors in sex determination. In the early stage of this study, high-throughput sequencing was used to screen the differentially expressed gene JUN in male and female embryonic stem cells (ESCs) and primordial germ cells (PGCs). The qRT-PCR discovered that the JUN gene significantly increased from embryonic days (E) 2.5 later in chicken embryo development, and the female gonad expression was much higher than that of the male after E14.5. Lentivirus shRNA-JUN, shRNA-Smad2 interference, and OE-JUN overexpression vectors were successfully constructed. After interfering with JUN in vivo, male characteristics appeared in ZW embryonic gonads at E18.5. Meanwhile, the male-specific genes DMRT1 and Sox9 were upregulated, the female-specific genes FOXL2, ESR1, and CYP19A1 were downregulated, and the estradiol in the gonads was significantly decreased. The situation was reversed after the overexpression of JUN, ZZ chicken embryo developed into female sexual characteristics. The double luciferase report has found that the Smad2 promoter activity was significantly upregulated after interference with JUN, and significantly increased after the deletion of the JUN binding site. After the injection of the Smad2-shRNA vector into the blood vessel in vivo, it was discovered that DMRT1 and Sox9 of ZW embryos at E18.5 were downregulated, FOXL2 and CYP19A1 were significantly upregulated, and the gonads show femininity. In conclusion, this study proves that JUN is a key regulator in the process of chicken female sex differentiation, which can inhibit the transcription of Smad2 and promote the synthesis of estradiol, and participate in the process of chicken sex differentiation. This study lays a foundation for the analysis of the molecular mechanism of chicken sex determination and the development of poultry sex control technology.

LncRNAs regulating stemness in aging

One of the most outstanding observations from next-generation sequencing approaches was that only 1.5% of our genes code for proteins. The biggest part is transcribed but give rise to different families of RNAs without coding potential. The functional relevance of these abundant transcripts remains far from elucidated. Among them are the long non-coding RNAs (lncRNAs), a relatively large and heterogeneous group of RNAs shown to be highly tissue-specific, indicating a prominent role in processes controlling cellular identity. In particular, lncRNAs have been linked to both stemness properties and detrimental pathways regulating the aging process, being novel players in the intricate network guiding tissue homeostasis. Here, we summarize the up-to-date information on the role of lncRNAs that affect stemness and hence impact upon aging, highlighting the likelihood that lncRNAs may represent an unexploited reservoir of potential therapeutic targets for reprogramming applications and aging-related diseases.

[ARTICLE WITHDRAWN] Long Noncoding RNA TUNAR Represses Growth, Migration, and Invasion of Human Glioma Cells Through Regulating miR-200a and Rac1

THIS ARTICLE WAS WITHDRAWN BY THE PUBLISHERS IN NOVEMBER 2020.

Long non-coding RNA THRIL promotes LPS-induced inflammatory injury by down-regulating microRNA-125b in ATDC5 cells

BACKGROUND

Osteoarthritis is an age-related disorder of bone-joint that causes pain and disability in middle and older people. This study aimed to investigate the potential effects of long non-coding RNA (lncRNA) THRIL on lipopolysaccharide (LPS)-induced osteoarthritis cell injury model (ATDC5 cell inflammatory injury), as well as the possible internal molecular mechanisms.

METHODS

Cell viability and apoptosis were assessed using CCK-8 assay and Guava Nexin assay, respectively. Cell transfection was conducted to change the expression of THRIL and microRNA-125b (miR-125b) in ATDC5 cells. qRT-PCR was performed to detect the expression of THRIL, miR-125b and pro-inflammatory cytokines IL-6, TNF-α and monocyte chemotactic protein 1 (MCP-1) in ATDC5 cells. ELISA was used to measure the concentrations of IL-6, TNF-α and MCP-1 in culture supernatant of ATDC5 cells. Finally, the protein expression of key factors involved in cell apoptosis, inflammatory response, JAK1/STAT3 and NF-κB pathways were evaluated using western blotting.

RESULTS

LPS significantly induced ATDC5 cell inflammatory injury and up-regulated the expression of THRIL. Overexpression of THRIL aggravated the LPS-induced ATDC5 cell inflammatory injury. Suppression of THRIL had opposite effects. Moreover, THRIL negatively regulated the expression of miR-125b in ATDC5 cells. miR-125b participated in the effects of THRIL overexpression on LPS-induced ATDC5 cell inflammatory injury. Furthermore, overexpression of THRIL enhanced the LPS-induced JAK1/STAT3 and NF-κB pathways activation by down-regulating miR-125b.

CONCLUSION

THRIL exerted pro-inflammatory roles in LPS-induced osteoarthritis cell injury model. Overexpression of THRIL promoted LPS-induced ATDC5 cell inflammatory injury by down-regulating miR-125b and then activating JAK1/STAT3 and NF-κB pathways.

Altered Expression of Differential Genes in Thoracic Spinal Cord Involved in Experimental Cholestatic Itch Mouse Model

The spinal origin of cholestatic itch in experimental obstructive jaundice mouse model remains poorly understood. In this study, the jaundice model was established by bile duct ligation (BDL) in mice, and differential gene expression patterns were analyzed in the lower thoracic spinal cord involved in cholestatic pruritus after BDL operation using high-throughput RNA sequencing. At 21st day after BDL, the expression levels of ENSRNOG00000060523, ENSRNOG00000058405 and ENSRNOG00000055193 mRNA were significantly up-regulated, and those of ENSRNOG00000042197, ENSRNOG00000008478, ENSRNOGOOOOOO19607, ENSRNOG00000020647, ENSRNOG00000046289, Gemin8, Serpina3n and Trim63 mRNA were significantly down-regulated in BDL group. The RNAseq data of selected mRNAs were validated by RT-qPCR. The expression levels of ENSRNOG00000042197, ENSRNOG00000008478, ENSRNOGOOOOOO 19607, ENSRNOG00000020647, ENSRNOG00000046289 and Serpina3n mRNA were significantly down-regulated in BDL group. This study suggested that cholestatic pruritus in experimental obstructive jaundice mouse model is related with in the changes of gene expression profiles in spinal cord.

Nanos2 promotes differentiation of chicken (Gallus gallus) embryonic stem cells to male germ cells

Nanos2 is an evolutionarily conserved RNA-binding protein containing 2 CCHC-type zinc finger motives. Here, we report that Nanos2 is strongly expressed in the testis compared to other tissues in chicken (Gallus gallus). Overexpression and knockout plasmid vectors were constructed, and in-vitro Cas9/gRNA digestion and T7 endonuclease I (T7E1) assay indicated that Nanos2-g1 possessed the highest knockout activity. In vitro and in vivo, Nanos2 overexpression accelerated the production of embryoid bodies (EBs) and SSC-like cells and promoted cvh, c-kit, and integrin α6 expression. Immunofluorescence staining, periodic acid schiff (PAS) and flow cytometry (FCM) assay showed that primordial germ cells (PGCs) and spermatogonial stem cells (SSCs) formation were significantly promoted. On the contrary, Nanos2 knockout delayed the production of EBs and SSC-like cells and correspondingly reduced cvh, c-kit, and integrin α6 expression. Simultaneously, the quantity of PGCs and SSCs was blocked. Collectively, these results uncovered a novel function of Nanos2 involved in chicken male germ cell differentiation, where it acts as a facilitator.

Altered expression of differential gene and lncRNA in the lower thoracic spinal cord on different time courses of experimental obstructive jaundice model accompanied with altered peripheral nociception in rats

The spinal origin of jaundice-induced altered peripheral nociceptive response poorly understood. In the current study, we aimed to first validate rats with bile duct ligation (BDL) as a jaundice model accompanied by altered peripheral nociceptive response, and then to analyze differential gene and lncRNA expression patterns in the lower thoracic spinal cord on different time courses after BDL operation by using high-throughput RNA sequencing. The differentially expressed genes (DEGs) identified using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis, followed by clustering analysis, Gene Ontology analysis and pathway analysis. As a result, a total of 2033 lncRNAs were differentially expressed 28d after BDL, in which 1545 probe sets were up-regulated and 488 probe sets were down-regulated, whereas a total of 2800 mRNAs were differentially expressed, in which 1548 probe sets were up-regulated and 1252 probe sets were down-regulated. The RNAseq data of select mRNAs and lncRNAs was validated by RT-qPCR. 28d after BDL, the expressions of lncRNA NONRATT002335 and NONRATT018085 were significantly up-regulated whereas the expression of lncRNA NONRATT025415, NONRATT025388 and NONRATT025409 was significantly down-regulated. 14d after BDL, the expressions of lncRNA NONRATT002335 and NONRATT018085 were significantly up-regulated; the expression of lncRNA NONRATT025415, NONRATT025388 and NONRATT025409 was significantly down-regulated. In conclusion, the present study showed that jaundice accompanied with decreased peripheral nociception involved in the changes of gene and lncRNA expression profiles in spinal cord. These findings extend current understanding of spinal mechanism for obstructive jaundice accompanied by decreased peripheral nociception.

Long noncoding RNA CASC2 predicts the prognosis of glioma patients and functions as a suppressor for gliomas by suppressing Wnt/β-catenin signaling pathway

BACKGROUND

Previous studies have demonstrated that long noncoding RNA cancer susceptibility candidate 2 (lncRNA CASC2) is frequently downregulated in several types of tumors and functions as a tumor-suppressive factor. However, the clinical significance and function of CASC2 in human glioma remain largely unknown. The purpose of this study was to identify the clinical values of CASC2, as well as investigate the potential molecular mechanisms in glioma.

METHODS

This retrospective study first analyzed the expression levels of CASC2 using quantitative real-time polymerase chain reaction. Then, CASC2 expression levels were associated with various clinicopathologic characteristics and the survival rate of patients with glioma. Finally, the function and underlying molecular mechanisms of CASC2 in human glioma were investigated in U251 cell line.

RESULTS

By quantitative real-time polymerase chain reaction analysis, our data showed that CASC2 expression was significantly downregulated in glioma tissues and cell lines (U87 and U251) compared to adjacent normal brain tissues or normal human astrocytes. Moreover, its expression negatively correlated with tumor grade in glioma patients. Furthermore, Kaplan-Meier curves with log-rank analysis revealed a close correlation between downregulated CASC2 and shorter survival time in glioma patients. In addition, Cox regression analysis indicated that CASC2 could be considered as an independent risk factor for poor prognosis. Finally, in vitro experiment demonstrated that CASC2 overexpression remarkably suppressed glioma cell proliferation, migration, and invasion through suppressing Wnt/β-catenin signaling pathway.

CONCLUSION

This study suggested that CASC2 may potentially serve as a valuable diagnostic and prognostic biomarker and a therapeutic target for glioma patients.