MAD2B acts as a negative regulatory partner of TCF4 on proliferation in human dermal papilla cells

miR-140-y targets TCF4 to regulate the Wnt signaling pathway and promote embryonic feather follicle development in Hungarian white goose

Goose down feather has become one of the most important economical products in the goose breeding industry and it provides several essential physiological roles in birds. Therefore, understanding and regulating the development of skin and feather follicles during embryogenesis is critical for avian biology and the poultry industry. MicroRNAs are known to play an important role in controlling gene expression during skin and feather follicle development. In this study, bioinformatics analysis was conducted to select miR-140-y as a potential miRNA involved in skin and feather follicle development and to predict TCF4 as its target gene. This gene was expressed at significant levels during embryonic feather follicle development, as identified by qPCR and Western blot. The targeting relationship was confirmed by a dual-luciferase assay in 293T cells. Then, the miR-140-y/TCF4 function in dermal fibroblast cells was explored. The results showed that miR-140-y could suppress the proliferation of goose embryonic dermal fibroblast cells (GEDFs) by suppressing the activity of some Wingless-types (Wnt) pathway related genes and proliferation marker genes, while miR-140-y inhibition led to the opposite effect. Similarly, the inhibition of the TCF4 gene results in blocking the proliferation of GEDFs by reducing the activity of some Wnt pathway-related genes. Finally, the co-transfection of miR-140-y inhibitor and siRNA-TCF4 results in a rescue of the TCF4 function and an increase of the Wnt signaling pathway and GEDFs proliferation. In conclusion, these results demonstrated that the miR-140-y-TCF4 axis influences the activity of the Wnt signaling pathway and works as a dynamic regulator during skin and feather follicle development.

AURKB promotes bladder cancer progression by deregulating the p53 DNA damage response pathway via MAD2L2

BACKGROUND

Bladder cancer (BC) is the most common urinary tract malignancy. Aurora kinase B (AURKB), a component of the chromosomal passenger protein complex, affects chromosomal segregation during cell division. Mitotic arrest-deficient 2-like protein 2 (MAD2L2) interacts with various proteins and contributes to genomic integrity. Both AURKB and MAD2L2 are overexpressed in various human cancers and have synergistic oncogenic effects; therefore, they are regarded as emerging therapeutic targets for cancer. However, the relationship between these factors and the mechanisms underlying their oncogenic activity in BC remains largely unknown. The present study aimed to explore the interactions between AURKB and MAD2L2 and how they affect BC progression via the DNA damage response (DDR) pathway.

METHODS

Bioinformatics was used to analyze the expression, prognostic value, and pro-tumoral function of AURKB in patients with BC. CCK-8 assay, colony-forming assay, flow cytometry, SA-β-gal staining, wound healing assay, and transwell chamber experiments were performed to test the viability, cell cycle progression, senescence, and migration and invasion abilities of BC cells in vitro. A nude mouse xenograft assay was performed to test the tumorigenesis ability of BC cells in vivo. The expression and interaction of proteins and the occurrence of the senescence-associated secretory phenotype were detected using western blot analysis, co-immunoprecipitation assay, and RT-qPCR.

RESULTS

AURKB was highly expressed and associated with prognosis in patients with BC. AURKB expression was positively correlated with MAD2L2 expression. We confirmed that AURKB interacts with, and modulates the expression of, MAD2L2 in BC cells. AURKB knockdown suppressed the proliferation, migration, and invasion abilities of, and cell cycle progression in, BC cells, inducing senescence in these cells. The effects of AURKB knockdown were rescued by MAD2L2 overexpression in vitro and in vivo. The effects of MAD2L2 knockdown were similar to those of AURKB knockdown. Furthermore, p53 ablation rescued the MAD2L2 knockdown-induced suppression of BC cell proliferation and cell cycle arrest and senescence in BC cells.

CONCLUSIONS

AURKB activates MAD2L2 expression to downregulate the p53 DDR pathway, thereby promoting BC progression. Thus, AURKB may serve as a potential molecular marker and a novel anticancer therapeutic target for BC.

CRABP2 Promotes the Proliferation of Dermal Papilla Cells via the Wnt/β-Catenin Pathway

In our previous study of Hu sheep hair follicles, we found that CRABP2 was highly expressed in DPCs, which suggested that CRABP2 may influence the number of DPCs. In the present study, we aimed to understand the effect of CRABP2 in Hu sheep dermal papilla cells (DPCs). First, we explored the influence of CRABP2 on the ability of Hu sheep DPCs' proliferation. Based on the results obtained from some experiments, such as CCK-8, EDU, qPCR, and Western blot experiment, we found that the overexpression of CRABP2 facilitated the proliferation of DPCs compared to the negative control group. Then, we also detected the effect of CRABP2 on the Wnt/β-catenin pathway based on the important function of the Wnt/β-catenin pathway in hair follicles. The results showed that CRABP2 could activate the Wnt/β-catenin pathway in DPCs, and it rescues the proliferation of DPCs when the Wnt/β-catenin pathway was inhibited. In summary, our findings indicate that CRABP2 is a vital functional gene in the proliferation of Hu sheep DPCs. Our study will be of great use for revealing the roles of CRABP2 in the hair follicles of Hu sheep.

Dissecting chicken germ cell dynamics by combining a germ cell tracing transgenic chicken model with single-cell RNA sequencing

Avian germ cells can be distinguished by certain characteristics during development. On the basis of these characteristics, germ cells can be used for germline transmission. However, the dynamic transcriptional landscape of avian germ cells during development is unknown. Here, we used a novel germ-cell-tracing method to monitor and isolate chicken germ cells at different stages of development. We targeted the deleted in azoospermia like (DAZL) gene, a germ-cell-specific marker, to integrate a green fluorescent protein (GFP) reporter gene without affecting endogenous DAZL expression. The resulting transgenic chickens (DAZL::GFP) were used to uncover the dynamic transcriptional landscape of avian germ cells. Single-cell RNA sequencing of 4,752 male and 13,028 female DAZL::GFP germ cells isolated from embryonic day E2.5 to 1 week post-hatch identified sex-specific developmental stages (4 stages in male and 5 stages in female) and trajectories (apoptosis and meiosis paths in female) of chicken germ cells. The male and female trajectories were characterized by a gradual acquisition of stage-specific transcription factor activities. We also identified evolutionary conserved and species-specific gene expression programs during both chicken and human germ-cell development. Collectively, these novel analyses provide mechanistic insights into chicken germ-cell development.

REV7: Jack of many trades

The HORMA domain protein REV7, also known as MAD2L2, interacts with a variety of proteins and thereby contributes to the establishment of different complexes. With doing so, REV7 impacts a diverse range of cellular processes and gained increasing interest as more of its activities became uncovered. REV7 has important roles in translesion synthesis and mitotic progression, and acts as a central component in the recently discovered shieldin complex that operates in DNA double-strand break repair. Here we discuss the roles of REV7 in its various complexes, focusing on its activity in genome integrity maintenance. Moreover, we will describe current insights on REV7 structural features that allow it to be such a versatile protein.

Multiple potential roles of thymosin β4 in the growth and development of hair follicles

The hair follicle (HF) is an important mini-organ of the skin, composed of many types of cells. Dermal papilla cells are important signalling components that guide the proliferation, upward migration and differentiation of HF stem cell progenitor cells to form other types of HF cells. Thymosin β4 (Tβ4), a major actin-sequestering protein, is involved in various cellular responses and has recently been shown to play key roles in HF growth and development. Endogenous Tβ4 can activate the mouse HF cycle transition and affect HF growth and development by promoting the migration and differentiation of HF stem cells and their progeny. In addition, exogenous Tβ4 increases the rate of hair growth in mice and promotes cashmere production by increasing the number of secondary HFs (hair follicles) in cashmere goats. However, the molecular mechanisms through which Tβ4 promotes HF growth and development have rarely been reported. Herein, we review the functions and mechanisms of Tβ4 in HF growth and development and describe the endogenous and exogenous actions of Tβ4 in HFs to provide insights into the roles of Tβ4 in HF growth and development.

Twist1 Contributes to the Maintenance of Some Biological Properties of Dermal Papilla Cells in vitro by Forming a Complex With Tcf4 and β-Catenin

OBJECTIVE

During hair follicle regeneration, hair follicle stem cells (HFSCs) are regulated by signals from dermal papilla cells (DPCs). Previously we found that Tcf4 could promote the proliferation of DPCs. In this study, we focused on whether and how the biological properties of Tcf4-induced DPCs were regulated by Twist1.

METHODS

Twist1 was overexpressed or knocked down in DPCs following different adenovirus or lentivirus infection. Phase-contrast microscopy was used to observe the agglutinative growth of DPCs. The CCK-8 assay was used to test the proliferation of DPCs. Western blot and qPCR experiments were used to determine the expression of HGF, IGF-1, VEGF, c-myc, survivin, and CyclinD1 in DPCs. ELISAs were used to test the growth factors secreted by DPCs. Conditional medium culture was used to detect the inductive ability of DPCs. Co-immunoprecipitation and immunofluorescence were used to test the binding of Twist1, Tcf4, and β-catenin in DPCs. Immunofluorescence was also used to test the expression of Twist1, Tcf4, and KRT15 in hair follicles.

RESULTS

Twist1 induced DPC agglutinative growth and proliferation. Twist1 upregulated the expression of downstream target genes downstream of Tcf4, c-myc, survivin, in Tcf4-induced DPCs, as well as the expression and secretion of growth factors HGF, IGF-1, VEGF, which had the ability to induce hair follicle growth. The conditional medium from Twist1-treated DPCs increased the expression of KRT40 and MSX2 in HaCaT cells. Twist1 and Tcf4 co-localized in DPCs both in vitro and in vivo. Anti-Twist1 precipitated Tcf4 and β-catenin.

CONCLUSION

These results indicate that Tcf4 and Twist1 play a synergistic role in regulating the hair follicle induction ability of DPCs. Twist1 functions by forming a ternary complex with Tcf4 and β-catenin. Thus, we report new data that elucidate whether and how Twist1 regulates some biological properties of DPCs.

Thymosin β4 Identified by Transcriptomic Analysis from HF Anagen to Telogen Promotes Proliferation of SHF-DPCs in Albas Cashmere Goat

Increasing cashmere yield is one of the important goals of cashmere goat breeding. To achieve this goal, we screened the key genes that can improve cashmere performance. In this study, we used the RNA raw datasets of the skin and dermal papilla cells of secondary hair follicle (SHF-DPCs) samples of hair follicle (HF) anagen and telogen of Albas cashmere goats and identified a set of significant differentially expressed genes (DEGs). To explore potential associations between gene sets and SHF growth features and to identify candidate genes, we detected functional enrichment and constructed protein-protein interaction (PPI) networks. Through comprehensive analysis, we selected Thymosin β4 (Tβ4), Rho GTPase activating protein 6 (ARHGAP6), ADAM metallopeptidase with thrombospondin type 1 motif 15, (ADAMTS15), Chordin (CHRD), and SPARC (Osteonectin), cwcv and kazal-like domains proteoglycan 1 (SPOCK1) as candidate genes. Gene set enrichment analysis (GSEA) for these genes revealed Tβ4 and ARHGAP6 have a close association with the growth and development of SHF-DPCs. However, the expression of Tβ4 in the anagen was higher than that in the telogen, so we finally chose Tβ4 as the ultimate research object. Overexpressing Tβ4 promoted and silencing Tβ4 inhibited the proliferation of SHF-DPCs. These findings suggest that Tβ4 can promote the growth and development of SHF-DPCs and indicate that this molecule may be a valuable target for increasing cashmere production.

Stra8 may inhibit apoptosis during mouse spermatogenesis via the AKT signaling pathway

Stimulated by retinoic acid 8 (Stra8), one of genes induced by retinoic acid (RA), is required for the meiotic initiation of male spermatogenesis. The present study found that Stra8 inhibited apoptosis in male Stra8‑knockout mice, and in mice with vitamin A deficiency and vitamin A recovery in vivo. This phenotype was also verified in GC1 spermatogonia (spg) cells overexpressing Stra8. In addition, microarray analysis identified that there were nine differentially expressed genes (DEGs) in the Stra8‑overexpressed GC1 spg cells compared with the control groups; the expression of these nine genes was verified via mRNA expression levels. The DEGs were as follows: Phosphatidylinositol‑dependent kinase 1 (PDK1), a key gene upstream of protein kinase B (AKT); angiopoietin 2, a B‑cell lymphoma 2 (Bcl‑2)‑inhibited gene; transcription factor 4, glutathione S‑transferase P91 and ubiquitin‑specific protease 33, mitogen‑activated protein kinase (MAPK)‑related genes; oxidative stress induced growth inhibitor 1, related to the P53 pathway; Bcl‑2, P53, ERK (MAPK1/3), c‑Jun N‑terminal kinase (MAPK8/9), and P38 (MAPK14), all of which are key genes involved in the AKT signaling pathway. Therefore, the present study further verified these genes and found that the mRNA and protein expression levels of PDK1, AKT, Bcl‑2 and ERK were increased. Although the mRNA expression level of P53 was decreased, there was no significant difference in the protein expression level in Stra8‑overexpressing GC1 spg cells compared with controls. In addition, Caspase 3, one of the executioner caspases, was decreased in Stra8‑overexpressing GC1 spg cells compared with the control groups. Therefore, it was suggested that Stra8 may directly or indirectly inhibit caspases through the AKT signaling pathway and ultimately exert an anti‑apoptotic effect in the male reproductive system.

miR-195-5p Regulates Hair Follicle Inductivity of Dermal Papilla Cells by Suppressing Wnt/β-Catenin Activation

Dermal papilla (DP) cells play a vital role in hair follicle (HF) development and postnatal hair cycling. However, the abilities are lost on further culture. Recent studies have demonstrated significant influences of posttranscriptional regulation by microRNA (miRNA) on HF development. The current study aims to investigate how miRNAs regulate Wnt/β-catenin to control HF inductivity of DP cells by performing microarray analysis in early- and late-passage DP cells and transfecting with miRNAs inhibitor or mimic. Results showed early-passage DP cells strongly expressed miRNAs related to inhibition of noncanonical Wnt pathways. In late-passage DP cells, miRNAs capable of inhibiting the canonical Wnt/β-catenin pathway were upregulated, in addition to the miRNAs targeting the noncanonical Wnt pathway. Moreover, we verified that β-catenin expression was downregulated by miR-195-5p overexpression in dose manner. Meanwhile LRP6 expression was downregulated in both protein and mRNA as well as the genes involved in the hair inductivity of DP cells. These results suggest that the appearance of miRNAs that suppress the Wnt/β-catenin pathway may be responsible for the loss of ability of DP cells in culture and miR-195-5p is the potential key factor involved in regulating HF inductivity of DP cells.