Sox6 suppression induces RA-dependent apoptosis mediated by BMP-4 expression during neuronal differentiation in P19 cells

LncRNA MIR181A2HG inhibits keratinocytes proliferation through miR-223-3p/SOX6 axis

BACKGROUND

Psoriasis is a complex and recurrent chronic inflammatory skin disease, and the abnormal proliferation of keratinocytes plays a crucial role in the pathogenesis of psoriasis. Long non-coding RNAs (lncRNAs) play an indispensable role in regulating cellular functions. This research aims to explore the potential impact of lncRNA MIR181A2HG on the regulation of keratinocyte proliferation.

METHODS

The expression level of MIR181A2HG and the mRNA level of KRT6, KRT16, and SOX6 were assessed using qRT-PCR. The viability and proliferation of keratinocytes were evaluated using CCK-8 and EdU assays. Cell cycle analysis was performed using flow cytometry. Dual-luciferase reporter assays were applied to test the interaction among MIR181A2HG/miR-223-3p/SOX6. Protein level was detected by Western blotting analysis.

RESULTS

The findings indicated that psoriasis lesions tissue exhibited lower levels of MIR181A2HG expression compared to normal tissue. The overexpression of MIR181A2HG resulted in the inhibition of HaCaT keratinocytes proliferation. The knockdown of MIR181A2HG promoted cell proliferation. The dual-luciferase reporter assay and rescue experiments provided evidence of the interaction among MIR181A2HG, SOX6, and miR-223-3p.

CONCLUSIONS

The lncRNA MIR181A2HG functions as a miR-223-3p sponge targeting SOX6 to regulate the proliferation of keratinocytes, which suggested that MIR181A2HG/miR-223-3p/SOX6 might be potential diagnostic and therapeutic targets for psoriasis.

miR-365-3p mediates BCL11A and SOX6 erythroid-specific coregulation: A new player in HbF activation

Hemoglobin switching is a complex biological process not yet fully elucidated. The mechanism regulating the suppression of fetal hemoglobin (HbF) expression is of particular interest because of the positive impact of HbF on the course of diseases such as β-thalassemia and sickle cell disease, hereditary hemoglobin disorders that affect the health of countless individuals worldwide. Several transcription factors have been implicated in the control of HbF, of which BCL11A has emerged as a major player in HbF silencing. SOX6 has also been implicated in silencing HbF and is critical to the silencing of the mouse embryonic hemoglobins. BCL11A and SOX6 are co-expressed and physically interact in the erythroid compartment during differentiation. In this study, we observe that BCL11A knockout leads to post-transcriptional downregulation of SOX6 through activation of microRNA (miR)-365-3p. Downregulating SOX6 by transient ectopic expression of miR-365-3p or gene editing activates embryonic and fetal β-like globin gene expression in erythroid cells. The synchronized expression of BCL11A and SOX6 is crucial for hemoglobin switching. In this study, we identified a BCL11A/miR-365-3p/SOX6 evolutionarily conserved pathway, providing insights into the regulation of the embryonic and fetal globin genes suggesting new targets for treating β-hemoglobinopathies.

Regulatory mechanisms of SoxD transcription factors and their influences on male fertility

Members of the SRY-related box (SOX) subfamily D (SoxD) of transcription factors are well conserved among vertebrate species and play important roles in different stages of male reproductive development. In mammals, the SoxD subfamily contains three members: SOX5, SOX6 and SOX13. Here, we describe their implications in testicular development and spermatogenesis, contributing to fertility. We also cover the mechanisms of action of SoxD transcription factors in gene regulation throughout male development. The specificity of activation of target genes by SoxD members depends, in part, on their post-translational modifications and interactions with other partners. Sperm production in adult males requires the coordination in the regulation of gene expression by different members of the SoxD subfamily of transcription factors in the testis. Specifically, the regulation of genes promoting adequate spermatogenesis by SoxD members is discussed in comparison between species.

MiR-17-3p inhibits osteoblast differentiation by downregulating Sox6 expression

Osteoporosis and osteoarthritis are orthopedic disorders that affect millions of elderly people worldwide; stimulation of bone formation is a potential therapeutic strategy for the treatment of these conditions. As the only bone‐forming cells, osteoblasts play a key role in bone reconstruction. The microRNA miR‐17‐3p is downregulated during osteogenic differentiation of human bone marrow mesenchymal stem cells, but its precise role in this process is unknown. Here, we investigated the role of miR‐17‐3p in osteoblast differentiation. An in vitro model of osteogenesis was established by treating MC3T3‐E1 murine preosteoblast cells with bone morphogenetic protein 2 (BMP2). The expression of miR‐17‐3p in BMP2‐induced MC3T3‐E1 cells was detected by reverse transcription‐quantitative PCR, and its effects on cells transfected with miR‐17‐3p mimic or inhibitor were evaluated by Alizarin Red staining, alkaline phosphatase (ALP) activity assay, and by detection of osteoblast markers including the ALP, collagen type I α1 chain, and osteopontin genes. Bioinformatics analysis was carried out to identify putative target genes of miR‐17‐3p, and the luciferase reporter assay was used for functional validation. Rescue experiments were performed to determine whether SRY‐box transcription factor 6 (Sox6) plays a role in the regulation of osteoblast differentiation by miR‐17‐3p. We report that miR‐17‐3p was downregulated upon BMP2‐induced osteoblast differentiation in MC3T3‐E1 cells, and this was accompanied by decreased differentiation and mineralization, ALP activity, and expression of osteogenesis‐related genes. Sox6 was confirmed to be a target gene of miR‐17‐3p in osteoblasts, and the inhibitory effect of miR‐17‐3p on osteoblast differentiation was observed to occur via Sox6. These results suggest the existence of a novel mechanism underlying miRNA‐mediated regulation of osteogenesis, which has potential implications for the treatment of orthopedic disorders.

miRNA‑342 suppresses renal interstitial fibrosis in diabetic nephropathy by targeting SOX6

Diabetic kidney disease (DKD) is one of the major microvascular complications in patients with type 1 and/or type 2 diabetes, the first cause of end-stage renal disease (ESRD) in several countries and regions. However, the pathogenesis of DKD and the mechanisms through which it leads to ESRD remain unknown. Thus, in this study, we aimed to elucidate some of these mechanisms. The expression of microRNA (miRNA or miR)-342-3p and SRY-box 6 (SOX6) in the renal tissues of mice with DKD and mouse renal mesangial cells (MCs) was determined by RT-qPCR and western blot analysis. The diabetic kidney environment was established using high-glucose medium. SOX6 was verified as a target gene of miR-342-3p by dual-luciferase activity assay. In addition, western blot analysis was employed to determine the changes in the levels of several biomarkers of fibrosis [transforming growth factor (TGF)-β1, fibronectin (FN), collagen IV (referred to as C-IV) and phosphatase and tensin homolog (PTEN)]. Compared with THE control mice, the expression of miR-342-3p in the kidney tissues of mice with DKD was down-regulated, whereas that of SOX6 was upregulated. The same phenomenon was observed in the MCs cultured in high-glucose medium. Subsequently, miR-342-3p inhibited SOX6 expression, promoted cell proliferation and inhibited the apoptosis of MCs. Moreover, the overexpression of miR-342-3p suppressed high glucose-induced renal interstitial fibrosis. In addition, it was found that miR-342-3p inhibited SOX6 expression by binding to the 3′-UTR of SOX6. On the whole, the findings of this study demonstrate that miR-342-3p suppresses the progression of DKD by inducing the degradation of SOX6. Thus, the miR-342-3p/SOX6 axis may serve as a novel therapeutic target in the treatment of DKD.

Transformation of the Transcriptomic Profile of Mouse Periocular Mesenchyme During Formation of the Embryonic Cornea

Purpose

Defects in neural crest development are a major contributing factor in corneal dysgenesis, but little is known about the genetic landscape during corneal development. The purpose of this study was to provide a detailed transcriptome profile and evaluate changes in gene expression during mouse corneal development.

Methods

RNA sequencing was used to uncover the transcriptomic profile of periocular mesenchyme (pNC) isolated at embryonic day (E) 10.5 and corneas isolated at E14.5 and E16.5. The spatiotemporal expression of several differentially expressed genes was validated by in situ hybridization.

Results

Analysis of the whole-transcriptome profile between pNC and embryonic corneas identified 3815 unique differentially expressed genes. Pathway analysis revealed an enrichment of differentially expressed genes involved in signal transduction (retinoic acid, transforming growth factor-β, and Wnt pathways) and transcriptional regulation.

Conclusions

Our analyses, for the first time, identify a large number of differentially expressed genes during progressive stages of mouse corneal development. Our data provide a comprehensive transcriptomic profile of the developing cornea. Combined, these data serve as a valuable resource for the identification of novel regulatory networks crucial for the advancement of studies in congenital defects, stem cell therapy, bioengineering, and adult corneal diseases.

MicroRNA-135a-5p promotes neuronal differentiation of pluripotent embryonal carcinoma cells by repressing Sox6/CD44 pathway

MicroRNA-135a-5p has been reported to play a potential role in the generation of new neurons. However, the underlying targets of miR-135a-5p in regulating neuronal differentiation have been poorly understood. Our study recently has uncovered that Sox6 and CD44 genes were significantly downregulated during neuronal differentiation of P19 cells, a multipotent cell type. We then found that Sox6 directly bound to the promoter of CD44. Importantly, we identified Sox6 as a direct target of miR-135a-5p. Additionally, we demonstrated that miR-135a-5p is crucial for the neuronal differentiation of P19 cells. More significantly, we found that Sox6 overexpression could overturn miR-135a-5p-mediated neuronal differentiation and dendrite development. In conclusion, these findings indicated that miR-135a-5p/Sox6/CD44 axis provides an important molecular target mechanism for neurodifferentiation.

Expression profiles of Sox transcription factors within the postnatal rodent testes

SRY-related box (Sox) transcription factors are conserved among vertebrate species. These proteins regulate multiple processes including sex determination and testis differentiation of the male embryo. Members of the Sox family have been identified in pre- and postnatal testis and are known to play an important role in sex determination (Sry, Sox9), male gonadal development, and fertility (Sox4, Sox8, Sox30). However, their expression profiles per cell types remain elusive. The objectives of this research were to characterize the expression profiles of Sox family members within adult testes using publically available datasets and to determine whether these findings are consistent with literature as well as immunofluorescence and in situ hybridization results. We have found that Sox4, Sox8, Sox9, and Sox12 are highly expressed in Sertoli cells, whereas Sox5, Sox6, and Sox30 were typically expressed in spermatocytes and spermatids. Spermatogonia were characterized by the expressions of Sox3, Sox4, Sox12, Sox13, and Sox18. Hence, these results suggest that Sox transcription factors may play different roles according to cell types of the adult mammalian testis.